Satellites Missions and Technologies

[17] Moen J, Oksavik K, Alfonsi L, Daabakk Y, Romano V, Spogli L. Space weather challenges of the polar cap ionosphere. Journal of Space

*Satellites Missions and Technologies for Geosciences*

Weather and Space Climate. 2013;**3**: A02. DOI: 10.1051/swsc/2013025

[18] Priyadarshi S, Zhang QH, Ma YZ, Wang Y, Xing ZY. Observations and modeling of ionospheric scintillations at South Pole during six X-class solar flares

in 2013. Journal of Geophysical Research: Space Physics. 2016;**121**: 5737-5751. DOI: 10.1002/2016JA022833

and differential carrier phase

[21] Tiwari R, Strangeways HJ. Regionally based alarm index to

[22] Kinter PM, Ledvina BM, de Paula ER. GPS and ionosphere scintillations. Space Weather. 2007;

**5**:S09003. DOI: 10.1029/

mitigate ionospheric scintillation effects for GNSS receivers. Space Weather. 2015;**13**:72-85. DOI: 10.1002/

209-224

3484-x

2014SW001115

2006SW000260

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[19] Bhattacharrya A et al. Nighttime equatorial ionosphere: GPS scintillations

fluctuations. Radio Science. 2000;**35**(1):

[20] Priyadarshi S, Zhang QH, Ma YZ. Antarctica SED/TOI associated ionospheric scintillation during 27 February 2014 geomagnetic storm. Astrophysics and Space Science. 2018; **363**:262. DOI: 10.1007/s10509-018-

**107**

**Abstract**

**Chapter 7**

Innovation

Earth Observation Technologies:

Low-End-Market Disruptive

*Daniel Garcia-Almiñana, Eloi Sierra, Jose S. Perez,* 

*Dhiren Kataria, Ronald Outlaw, Leonardo Ghizoni,* 

*Steve Edmondson, Sarah Haigh, Nicholas H. Crisp,* 

*Vitor T.A. Oiko, Rachel E. Lyons, Stephen D. Worral,* 

*Yung-An Chan, Adam Boxberger, Stefanos Fasoulas,* 

*Jonas Morsbøl, Ameli Schwalber and Barbara Heißerer*

have been disrupting the EO market in front of traditional platforms.

After decades of traditional space businesses, the space paradigm is changing. New approaches to more efficient missions in terms of costs, design, and manufacturing processes are fostered. For instance, placing big constellations of micro- and nano-satellites in Low Earth Orbit and Very Low Earth Orbit (LEO and VLEO) enables the space community to obtain a huge amount of data in near real-time with an unprecedented temporal resolution. Beyond technology innovations, other drivers promote innovation in the space sector like the increasing demand for Earth Observation (EO) data by the commercial sector. Perez et al. stated that the EO industry is the second market in terms of operative satellites (661 units), micro- and nano-satellites being the higher share of them (61%). Technological and market drivers encourage the emergence of new start-ups in the space environment like Skybox, OneWeb, Telesat, Planet, and OpenCosmos, among others, with novel business models that change the accessibility, affordability, ownership, and commercialization of space products and services. This chapter shows some results of the H2020 DISCOVERER (DISruptive teChnOlogies for VERy low Earth oRbit platforms) Project and focuses on understanding how micro- and nano-satellites

*Constantin Traub, Victor Jungnell, Kristian Bay,* 

*Sabrina Livadiotti, Claire Huyton, Luciana A. Sinpetru,* 

*Rosa M. Domínguez, David González, Francesco Romano,* 

*Peter C.E. Roberts, Jonathan Becedas, Georg H. Herdrich,* 

*Rachel Villain, Alexis Conte, Badia Belkouchi, Kate Smith,* 

*Silvia Rodriguez-Donaire, Miquel Sureda,* 

#### **Chapter 7**

## Earth Observation Technologies: Low-End-Market Disruptive Innovation

*Silvia Rodriguez-Donaire, Miquel Sureda, Daniel Garcia-Almiñana, Eloi Sierra, Jose S. Perez, Peter C.E. Roberts, Jonathan Becedas, Georg H. Herdrich, Dhiren Kataria, Ronald Outlaw, Leonardo Ghizoni, Rachel Villain, Alexis Conte, Badia Belkouchi, Kate Smith, Steve Edmondson, Sarah Haigh, Nicholas H. Crisp, Vitor T.A. Oiko, Rachel E. Lyons, Stephen D. Worral, Sabrina Livadiotti, Claire Huyton, Luciana A. Sinpetru, Rosa M. Domínguez, David González, Francesco Romano, Yung-An Chan, Adam Boxberger, Stefanos Fasoulas, Constantin Traub, Victor Jungnell, Kristian Bay, Jonas Morsbøl, Ameli Schwalber and Barbara Heißerer*

#### **Abstract**

After decades of traditional space businesses, the space paradigm is changing. New approaches to more efficient missions in terms of costs, design, and manufacturing processes are fostered. For instance, placing big constellations of micro- and nano-satellites in Low Earth Orbit and Very Low Earth Orbit (LEO and VLEO) enables the space community to obtain a huge amount of data in near real-time with an unprecedented temporal resolution. Beyond technology innovations, other drivers promote innovation in the space sector like the increasing demand for Earth Observation (EO) data by the commercial sector. Perez et al. stated that the EO industry is the second market in terms of operative satellites (661 units), micro- and nano-satellites being the higher share of them (61%). Technological and market drivers encourage the emergence of new start-ups in the space environment like Skybox, OneWeb, Telesat, Planet, and OpenCosmos, among others, with novel business models that change the accessibility, affordability, ownership, and commercialization of space products and services. This chapter shows some results of the H2020 DISCOVERER (DISruptive teChnOlogies for VERy low Earth oRbit platforms) Project and focuses on understanding how micro- and nano-satellites have been disrupting the EO market in front of traditional platforms.

**Keywords:** disruptive innovation, low-end market, micro- and nano-satellites, new space, Earth Observation

#### **1. Introduction**

Although Earth Observation (EO) started as an activity exclusively affordable for governments or big players in space with vast financial resources to sustain expensive programmes, it is no longer an exclusive and expensive industry. It allows the emergence of start-ups and spin-offs from academia and emerging countries that are the foundations of the *New Space*. This phenomenon, known as the democratization of space, changes the accessibility, affordability, and commercialization of space products and services to companies of all types and sizes [1].

According to [2], New Space can be understood as a disruptive trend whose aim is to transform space into a commodity by taking advantage from the joint between Information Technology (IT) and EO. Even though its origins were in Silicon Valley, the trend is now extended worldwide.

Regarding the Union of Concerned Scientists (UCS) satellite database, 1980 operational satellites were orbiting the Earth at the end of April 2018, with 684 of these aimed to EO [3]. This represents a growth of 250% compared to January 2014, when there were only 192 active EO satellites. From this huge increase, it is clear that EO data acquisition is an emerging market. With the number of companies growing year-by-year and optimistic forecasts, it can be reinforced that "EO is on its earlier days and there are still a lot of improvements to do and problems to solve" [4].

Looking at the new EO-based markets, it is observed in [2, 5] some signs of potential disruptive innovation in the space sector. Some technological drivers promote this innovation. For instance, low cost access to earth imagery; availability of high-quality spatial, spectral and temporal imagery; innovations in

**Figure 1.** *Micro- and nano-satellites launched between 1997 and 2017, classified by sectors (own elaboration).*

**109**

**Table 1.**

*Earth Observation Technologies: Low-End-Market Disruptive Innovation*

governmental programmes to other industries and services.

nity, working with almost every launch vehicle provider on the planet.

The term *disruptive innovation* was popularized in 2003 by Clayton M. Christensen, professor at Harvard Business School. In [6], he distinguished between sustaining and disruptive technologies and later, in [7], it replaced the term *technology* with *innovation*, since disruption does not come from technology but from businesses. According to [7], sustaining innovations foster improved product performance, while disruptive innovations bring to the market a very different value proposition, with a performance that is initially below the mainstream

products, but with low prices or unique features that compensate for it.

**Space situation**

specific missions

risk-averse culture

background

Additionally, in [6], a distinction between low-end-market and new-market innovations is made. Low-end-market innovations are those that do not result in

Closed sector (−) Space is a closed sector with little exchange of resources outside of aerospace and

Risk adversity (−) Space activities are high-risk efforts and they do not offer opportunities for error

intersection of domains and disciplines

Space missions remain technically very challenging and their components and technologies are still one-off prototypes, custom-designed, and optimized for

defense. However, innovations, especially the disruptive ones, appear from the

corrections after launch. This leaves little freedom for innovation and leads to a

Space workforce is highly educated and mobile and has a diverse cultural

Without open competitive markets, space innovations are likely considered useless for businesses. Additionally, high entry barriers and huge launching costs reduce the stimuli of industrial and private sectors to invest in space innovations

computer science, like cloud computing and machine learning; and some specific programmes, like Copernicus, that transfer high technology development from

Beyond technological drivers, other drivers promote the disruptive innovation in the space sector, such as the sharing economy, the increasing demand of the commercial sector—like smart cities—and the government interests in environmental monitoring. For example, Spaceflight offers companies a global launching opportu-

All of these drivers encourage new companies—like Skybox, SpaceX, OneWeb, Telesat, Planet, and OpenCosmos, among others—to develop new business models that make space more accessible and affordable for nongovernmental organizations

**Figure 1** summarizes the total number of micro- and nano-satellites launched per year between 2001 and 2017. Micro-satellites are loosely defined as any satellite weighting between 10 and 100 kg, while nano-satellites weight less than 10 kg. They have been classified by sectors to emphasize the huge increase of commercial microand nano-satellites launched in recent years compared to those launched by defense

*DOI: http://dx.doi.org/10.5772/intechopen.90923*

on shorter periods.

**Factors affecting innovation**

Highly skilled workforce (+)

High entrance barriers and open competitive markets (−)

*Factors affecting space innovation [5].*

Challenging objectives and attractive environments (+)

departments and governments.

**2. Hypotheses: disruption in EO technologies**

#### *Earth Observation Technologies: Low-End-Market Disruptive Innovation DOI: http://dx.doi.org/10.5772/intechopen.90923*

*Satellites Missions and Technologies for Geosciences*

new space, Earth Observation

the trend is now extended worldwide.

**1. Introduction**

**Keywords:** disruptive innovation, low-end market, micro- and nano-satellites,

of space products and services to companies of all types and sizes [1].

Although Earth Observation (EO) started as an activity exclusively affordable for governments or big players in space with vast financial resources to sustain expensive programmes, it is no longer an exclusive and expensive industry. It allows the emergence of start-ups and spin-offs from academia and emerging countries that are the foundations of the *New Space*. This phenomenon, known as the democratization of space, changes the accessibility, affordability, and commercialization

According to [2], New Space can be understood as a disruptive trend whose aim is to transform space into a commodity by taking advantage from the joint between Information Technology (IT) and EO. Even though its origins were in Silicon Valley,

Regarding the Union of Concerned Scientists (UCS) satellite database, 1980 operational satellites were orbiting the Earth at the end of April 2018, with 684 of these aimed to EO [3]. This represents a growth of 250% compared to January 2014, when there were only 192 active EO satellites. From this huge increase, it is clear that EO data acquisition is an emerging market. With the number of companies growing year-by-year and optimistic forecasts, it can be reinforced that "EO is on its earlier days and there are still a lot of improvements to do and problems to solve" [4]. Looking at the new EO-based markets, it is observed in [2, 5] some signs of potential disruptive innovation in the space sector. Some technological drivers promote this innovation. For instance, low cost access to earth imagery; availability of high-quality spatial, spectral and temporal imagery; innovations in

**108**

**Figure 1.**

*Micro- and nano-satellites launched between 1997 and 2017, classified by sectors (own elaboration).*

computer science, like cloud computing and machine learning; and some specific programmes, like Copernicus, that transfer high technology development from governmental programmes to other industries and services.

Beyond technological drivers, other drivers promote the disruptive innovation in the space sector, such as the sharing economy, the increasing demand of the commercial sector—like smart cities—and the government interests in environmental monitoring. For example, Spaceflight offers companies a global launching opportunity, working with almost every launch vehicle provider on the planet.

All of these drivers encourage new companies—like Skybox, SpaceX, OneWeb, Telesat, Planet, and OpenCosmos, among others—to develop new business models that make space more accessible and affordable for nongovernmental organizations on shorter periods.

**Figure 1** summarizes the total number of micro- and nano-satellites launched per year between 2001 and 2017. Micro-satellites are loosely defined as any satellite weighting between 10 and 100 kg, while nano-satellites weight less than 10 kg. They have been classified by sectors to emphasize the huge increase of commercial microand nano-satellites launched in recent years compared to those launched by defense departments and governments.

#### **2. Hypotheses: disruption in EO technologies**

The term *disruptive innovation* was popularized in 2003 by Clayton M. Christensen, professor at Harvard Business School. In [6], he distinguished between sustaining and disruptive technologies and later, in [7], it replaced the term *technology* with *innovation*, since disruption does not come from technology but from businesses. According to [7], sustaining innovations foster improved product performance, while disruptive innovations bring to the market a very different value proposition, with a performance that is initially below the mainstream products, but with low prices or unique features that compensate for it.

Additionally, in [6], a distinction between low-end-market and new-market innovations is made. Low-end-market innovations are those that do not result in


#### **Table 1.**

*Factors affecting space innovation [5].*

better product performance but offer lower prices, such as Walmart and its cheap retailing malls. On the other hand, new-market innovations, like the iPod, serve new users who had not owned or used the previous generation of products.

Christensen approached disruptive innovations from the point of view of both management and industry. However, his recommendations are kept at industrial level. Despite his product performance and business strategy analysis, his definition does not identify the innovation characteristics, since they are intrinsic rather than external factors that change over time, like customer perception or government regulations.

In [5], the concept of innovation is applied to the space environment. The author stated that some factors would affect the likelihood of innovation within the European space sector. **Table 1** summarizes these factors, dividing them between those that promote space innovation (+) and those that prevent it (−).

In [8], the previous concept of disruptive innovation is refined by identifying three innovation characteristics: functionality, discontinuous technical standards, and ownership models. His definition broadens the meaning of low-end market and new market innovations.

**Low-end market innovations** *are those with discontinuous technical standards that disrupt markets by using new, less costly materials or new production processes in the creation of existing technologies* [9, 10] *or new forms of ownership. These forms dictate how innovations are received in a marketplace, as they establish prices and innovation-related services among others* [11].

**New-market innovations** *are those with a disruptive functionality that provides the user with the ability to undertake a new behavior or accomplish a new task that was impossible before* [12–14].

Taking the above signs of innovation in the space sector and following the strategy developed in [7, 8], recent micro- and nano-satellite EO missions seem to show the key characteristics of disruptive innovation. **Table 2** summarizes the characteristics of micro- and nano-satellites as disruptive innovations according to different authors.

By combining the above-presented characteristics of disruptive micro- and nano-satellite innovations with the main specificities of the EO space market, a set of six hypotheses for micro- and nano-space market disruption has been developed


**111**

novel products.

*Earth Observation Technologies: Low-End-Market Disruptive Innovation*

Standardization The space sector has a low level of risk acceptance, which leaves

Performance Micro- and nano-satellites improve their performance in a pace

Affordability Traditional, established space companies are ignoring the market

Ownership forms Recent evolutions in micro- and nano-satellite technologies

*Summary of studied hypothesis related to the disruptive innovation characteristics.*

little freedom for innovation. However, micro- and nanosatellites provide simplicity and standardization in terms of design and manufacturing, This leads to a higher level of risk acceptance and, consequently, more innovation

Data accessibility and technology standardization are essential conditions to open new market opportunities

that meets market needs even though they have an inferior performance than those of traditional EO spacecraft

due to very low-profit margins. This fact leaves room for new entrants with totally different business models. These new actors bet on low-cost technology to produce more affordable space systems for Earth Observation

are affecting the forms of ownership and operability of EO systems, which were formerly owned by governments or public organizations

Micro- and nano-satellite missions offer disruptive functionalities that provide novel products or services that were unthinkable or impossible with traditional spacecraft missions

**Hypothesis to test Hypothesis** 

**label**

1

2

3

4

5

6

and presented in **Table 3**. In this section, all mentioned characteristics are tested to verify if the authors' hypotheses are true in order to clarify whether micro- and

In this section, the analysis of the six hypotheses stated in **Table 3** for micro- and nano-space market disruption has been done. The first hypothesis is related to space market standardization, the second hypothesis is related to market opportunities, the third hypothesis is related to micro- and nano-satellite performance, the fourth hypothesis is related to the affordability of the new space technologies for EO, the fifth hypothesis is related to the forms of ownership and operability of EO systems, and finally, the sixth hypothesis is related to disruptive functionalities that provide

**3.1 Hypothesis 1: micro- and nano-satellite simplicity and standardization**

*leads to a higher level of risk acceptance and, consequently, more innovation.*

In mainstream space platforms, each of design, development, and test campaign

H1: *The space sector has a low level of risk acceptance, which leaves little freedom for innovation. However, micro- and nano-satellites provide simplicity and standardization in terms of design and manufacturing. This* 

tends to be almost unique, custom-made for the specific mission. Long project

nano-satellites are disruptive for the EO market.

**3. Analysis: disruption in EO technologies**

*DOI: http://dx.doi.org/10.5772/intechopen.90923*

**Characteristics of disruptive innovations**

New market opportunities

Disruptive functionality

**Table 3.**

**Table 2.**

*Characteristics of micro- and nano-satellites as disruptive innovation in space [2, 5, 7, 8].*


*Earth Observation Technologies: Low-End-Market Disruptive Innovation DOI: http://dx.doi.org/10.5772/intechopen.90923*

#### **Table 3.**

*Satellites Missions and Technologies for Geosciences*

new market innovations.

*and innovation-related services among others* [11].

different authors.

**innovations**

(simplicity) Accessibility

Affordability Forms of ownership

High level of risk

Inferior performance Performance improvement Disruptive functionality

**Characteristics of disruptive** 

Discontinuous technical standards

Enabling new market opportunities

better product performance but offer lower prices, such as Walmart and its cheap retailing malls. On the other hand, new-market innovations, like the iPod, serve new users who had not owned or used the previous generation of products.

Christensen approached disruptive innovations from the point of view of both management and industry. However, his recommendations are kept at industrial level. Despite his product performance and business strategy analysis, his definition does not identify the innovation characteristics, since they are intrinsic rather than external factors that change over time, like customer perception or government regulations. In [5], the concept of innovation is applied to the space environment. The author stated that some factors would affect the likelihood of innovation within the European space sector. **Table 1** summarizes these factors, dividing them between

In [8], the previous concept of disruptive innovation is refined by identifying three innovation characteristics: functionality, discontinuous technical standards, and ownership models. His definition broadens the meaning of low-end market and

**Low-end market innovations** *are those with discontinuous technical standards that disrupt markets by using new, less costly materials or new production processes in the creation of existing technologies* [9, 10] *or new forms of ownership. These forms dictate how innovations are received in a marketplace, as they establish prices* 

**New-market innovations** *are those with a disruptive functionality that provides the user with the ability to* 

Taking the above signs of innovation in the space sector and following the strategy developed in [7, 8], recent micro- and nano-satellite EO missions seem to show the key characteristics of disruptive innovation. **Table 2** summarizes the characteristics of micro- and nano-satellites as disruptive innovations according to

*undertake a new behavior or accomplish a new task that was impossible before* [12–14].

By combining the above-presented characteristics of disruptive micro- and nano-satellite innovations with the main specificities of the EO space market, a set of six hypotheses for micro- and nano-space market disruption has been developed

> **Christensen and Raynor [7]**

*Characteristics of micro- and nano-satellites as disruptive innovation in space [2, 5, 7, 8].*

**Summerer [5]**

**Nagy et al. [8]** **Denis et al. [2]**

those that promote space innovation (+) and those that prevent it (−).

**110**

**Table 2.**

*Summary of studied hypothesis related to the disruptive innovation characteristics.*

and presented in **Table 3**. In this section, all mentioned characteristics are tested to verify if the authors' hypotheses are true in order to clarify whether micro- and nano-satellites are disruptive for the EO market.

#### **3. Analysis: disruption in EO technologies**

In this section, the analysis of the six hypotheses stated in **Table 3** for micro- and nano-space market disruption has been done. The first hypothesis is related to space market standardization, the second hypothesis is related to market opportunities, the third hypothesis is related to micro- and nano-satellite performance, the fourth hypothesis is related to the affordability of the new space technologies for EO, the fifth hypothesis is related to the forms of ownership and operability of EO systems, and finally, the sixth hypothesis is related to disruptive functionalities that provide novel products.

#### **3.1 Hypothesis 1: micro- and nano-satellite simplicity and standardization**

H1: *The space sector has a low level of risk acceptance, which leaves little freedom for innovation. However, micro- and nano-satellites provide simplicity and standardization in terms of design and manufacturing. This leads to a higher level of risk acceptance and, consequently, more innovation.*

In mainstream space platforms, each of design, development, and test campaign tends to be almost unique, custom-made for the specific mission. Long project

durations and high costs are consequences of the complexity that implies the need of guaranteeing the maximum quality, hence the minimum risk for the mission.

On the other hand, micro- and nano-satellite constellations are based on the concept of standardization, which opens up the possibility of using commercial electronic components and the choice of numerous technology suppliers. In that way, it is possible to create less expensive satellites in shorter periods. Depending on the specifications, a micro-satellite can be built and placed in orbit for a few million euros and a nano-satellite for almost a quarter million. In comparison, the cost of a large satellite can rise to 500 million euros [4, 15].

Apart from the cost and size, the main benefit of micro- and nano-satellites is the time required to design and implement each model. As an average, a micro- or a nano-satellite can be designed, manufactured, and launched within less than 2 years [4, 15]. This means that large constellations of small satellites can be regularly renewed with state-of-the-art systems, ensuring optimal performance even if some units are lost or fail. This is not the case of conventional satellites, which are developed and launched within expensive and long projects that last between 5 and 10 years and, accordingly, cannot afford any failure in the platform without risking the entire mission.

Particularly worthy of mention is the recent emergence of many dedicated micro-launchers designed to place small satellites in orbit. So far, micro- and nano-satellites are launched at marginal costs as "piggyback" payload alongside traditional spacecraft. However, new micro-launcher concepts may be responsible for providing simplicity and standardization to the whole process, lowering launch costs if they demonstrate reliability and good performance [1].

*For the stated reasons, H1 can be supported, since micro- and nano-satellite design and manufacturing is focused on simple and standard equipment that eventually may increase the linked risk acceptance*.

#### **3.2 Hypothesis 2: new market opportunities**

H2: *Data accessibility and technology standardization are essential conditions to open new market opportunities*.

EO is a promising, fast-growing field boosted by a wide range of applications across various economic sectors, including precision farming, natural resource monitoring, oil and gas exploration, meteorology, civil protection, insurance, and urban monitoring [1]. The emergence of low-cost micro- and nano-satellites enabled EO start-ups to attract new markets interested in their tremendous amount of accessible and affordable high-resolution images. Additionally, more and more countries invest in their EO capacity, confirming the soft power dimension of space but also opening new market opportunities for international or regional cooperation [1].

Not only space is becoming more accessible through new launch technology, but also data from programs like US Landsat and Europe's Sentinel program are already available to all. This allows third parties to develop new services and applications over high-quality databases supported by different funding programs. For instance, OneAtlas updated the base map of the whole world with high-resolution imagery without taking any picture or OneWeb plan to use small spacecraft technology to make satellite Internet available on a global scale.

It is clear that some of these new markets are recently gaining access to EO data because it is cheaper than before. However, a very important entry barrier was also the traditional space companies themselves, because data owned and controlled by defense and public organizations were not available at any price.

**113**

offering comparable data.

**Figure 2.**

33% of the value-added market.

*Earth Observation Technologies: Low-End-Market Disruptive Innovation*

In **Figure 2**, it can be seen that in the year 2017, defense represented more than 60% of the commercial data market (\$1.8 billion), with infrastructure and natural resources verticals accounting a similar share to each other. These three vertical markets represented 80% of the commercial data market in 2017. Looking to the future, Euroconsult forecasts that the market for commercial EO data is expected to reach \$3 billion (5% of the Compound Annual Growth Rate (CAGR)) in 2026 [1]. In the short term, growth is expected to continue to be driven by the defense, with ongoing regional unrest and growing Image Intelligence needs of countries without proprietary military systems. By 2026, the defense is expected to represent 46% of the total market value (\$1.7 billion). Therefore, although defense will continue to be the major client for EO imagery, their share will reduce in the coming years. Other applications, such as maritime, infrastructure, and resource monitoring will support growth in the long term. Together with defense, these applications should have a 5% CAGR through 2026. Emerging applications in these sectors such as critical infrastructure monitoring and precision agriculture benefit from more capable satellite systems (i.e., a combination of higher ground resolution with higher temporal resolution). Location-Based Services (LBS) applications, including financial and insurance services, have been slow to develop, but the longer-term outlook for these services remains positive with the availability of new satellite capacity. For LBS applications, greater emphasis is expected to be put on integrated product offerings, emphasizing requiring the development of change detection analytics. In terms of revenue generation by data type, VHR optical is expected to remain the most significant in terms of data sales. More moderate-resolution datasets will be challenged by the availability of free solutions and low-cost systems

*Commercial EO data market in 2017 (left) and value-added services market in 2017 (right) [1].*

According to [1], in 2016, the market for Value-Added Services (VAS) was \$3.5 billion. This discounts the purchase of commercial data to develop geospatial solutions. Key markets for VAS do not mirror those for commercial data sales. Defense, while representing 61% of the commercial data market, only represents 15% of the VAS market; conversely, infrastructure and engineering (which incorporated cartography, cadastre, etc.) is only 10% of the commercial data market but

According to [1], the reasoning for this is relatively straightforward: defense end-users purchase data with much value-added analytics performed in-house. On the other hand, lower-cost, coarser resolution, and lower geolocation accuracy data can be leveraged with value-adding to form greater value products and services. Environmentmonitoring users, for instance, procure limited commercial data but are developing

*DOI: http://dx.doi.org/10.5772/intechopen.90923*

#### *Earth Observation Technologies: Low-End-Market Disruptive Innovation DOI: http://dx.doi.org/10.5772/intechopen.90923*

*Satellites Missions and Technologies for Geosciences*

large satellite can rise to 500 million euros [4, 15].

the entire mission.

*increase the linked risk acceptance*.

regional cooperation [1].

**3.2 Hypothesis 2: new market opportunities**

make satellite Internet available on a global scale.

defense and public organizations were not available at any price.

durations and high costs are consequences of the complexity that implies the need of guaranteeing the maximum quality, hence the minimum risk for the mission. On the other hand, micro- and nano-satellite constellations are based on the concept of standardization, which opens up the possibility of using commercial electronic components and the choice of numerous technology suppliers. In that way, it is possible to create less expensive satellites in shorter periods. Depending on the specifications, a micro-satellite can be built and placed in orbit for a few million euros and a nano-satellite for almost a quarter million. In comparison, the cost of a

Apart from the cost and size, the main benefit of micro- and nano-satellites is the time required to design and implement each model. As an average, a micro- or a nano-satellite can be designed, manufactured, and launched within less than 2 years [4, 15]. This means that large constellations of small satellites can be regularly renewed with state-of-the-art systems, ensuring optimal performance even if some units are lost or fail. This is not the case of conventional satellites, which are developed and launched within expensive and long projects that last between 5 and 10 years and, accordingly, cannot afford any failure in the platform without risking

Particularly worthy of mention is the recent emergence of many dedicated micro-launchers designed to place small satellites in orbit. So far, micro- and nano-satellites are launched at marginal costs as "piggyback" payload alongside traditional spacecraft. However, new micro-launcher concepts may be responsible for providing simplicity and standardization to the whole process, lowering launch

*For the stated reasons, H1 can be supported, since micro- and nano-satellite design and manufacturing is focused on simple and standard equipment that eventually may* 

EO is a promising, fast-growing field boosted by a wide range of applications across various economic sectors, including precision farming, natural resource monitoring, oil and gas exploration, meteorology, civil protection, insurance, and urban monitoring [1]. The emergence of low-cost micro- and nano-satellites enabled EO start-ups to attract new markets interested in their tremendous amount of accessible and affordable high-resolution images. Additionally, more and more countries invest in their EO capacity, confirming the soft power dimension of space but also opening new market opportunities for international or

H2: *Data accessibility and technology standardization are essential conditions to open new market opportunities*.

Not only space is becoming more accessible through new launch technology, but also data from programs like US Landsat and Europe's Sentinel program are already available to all. This allows third parties to develop new services and applications over high-quality databases supported by different funding programs. For instance, OneAtlas updated the base map of the whole world with high-resolution imagery without taking any picture or OneWeb plan to use small spacecraft technology to

It is clear that some of these new markets are recently gaining access to EO data because it is cheaper than before. However, a very important entry barrier was also the traditional space companies themselves, because data owned and controlled by

costs if they demonstrate reliability and good performance [1].

**112**

**Figure 2.** *Commercial EO data market in 2017 (left) and value-added services market in 2017 (right) [1].*

In **Figure 2**, it can be seen that in the year 2017, defense represented more than 60% of the commercial data market (\$1.8 billion), with infrastructure and natural resources verticals accounting a similar share to each other. These three vertical markets represented 80% of the commercial data market in 2017. Looking to the future, Euroconsult forecasts that the market for commercial EO data is expected to reach \$3 billion (5% of the Compound Annual Growth Rate (CAGR)) in 2026 [1].

In the short term, growth is expected to continue to be driven by the defense, with ongoing regional unrest and growing Image Intelligence needs of countries without proprietary military systems. By 2026, the defense is expected to represent 46% of the total market value (\$1.7 billion). Therefore, although defense will continue to be the major client for EO imagery, their share will reduce in the coming years. Other applications, such as maritime, infrastructure, and resource monitoring will support growth in the long term. Together with defense, these applications should have a 5% CAGR through 2026. Emerging applications in these sectors such as critical infrastructure monitoring and precision agriculture benefit from more capable satellite systems (i.e., a combination of higher ground resolution with higher temporal resolution). Location-Based Services (LBS) applications, including financial and insurance services, have been slow to develop, but the longer-term outlook for these services remains positive with the availability of new satellite capacity. For LBS applications, greater emphasis is expected to be put on integrated product offerings, emphasizing requiring the development of change detection analytics. In terms of revenue generation by data type, VHR optical is expected to remain the most significant in terms of data sales. More moderate-resolution datasets will be challenged by the availability of free solutions and low-cost systems offering comparable data.

According to [1], in 2016, the market for Value-Added Services (VAS) was \$3.5 billion. This discounts the purchase of commercial data to develop geospatial solutions. Key markets for VAS do not mirror those for commercial data sales. Defense, while representing 61% of the commercial data market, only represents 15% of the VAS market; conversely, infrastructure and engineering (which incorporated cartography, cadastre, etc.) is only 10% of the commercial data market but 33% of the value-added market.

According to [1], the reasoning for this is relatively straightforward: defense end-users purchase data with much value-added analytics performed in-house. On the other hand, lower-cost, coarser resolution, and lower geolocation accuracy data can be leveraged with value-adding to form greater value products and services. Environmentmonitoring users, for instance, procure limited commercial data but are developing

solutions using scientific and coarse resolution data, for example, pollution/aerosol monitoring and climate modeling. Many infrastructure applications for mapping also can be developed by using Landsat and Sentinel data that are free of charge.

In [1], it is also forecast that data also add to the belief that by making coarserresolution data free, the value-added services industry can leverage this to build greater value services with the potential for two very different businesses: a "highend" data market to support defense and free/low-cost data sources to support commercial and civil government applications.

*For these reasons, H2 would also be supported, since new market opportunities are growing and standardization has been proven as H1*.

#### **3.3 Hypothesis 3: micro- and nano-satellites performance**

H3: *Micro- and nano-satellites improve their performance in a pace that meets EO market needs despite having an inferior performance than those of traditional EO spacecraft*.

EO optical imaging satellite performance is defined in terms of spatial and temporal resolution. Spatial resolution relates to the level of detail obtained from an image and can be measured by the Ground Sample Distance (GSD), which is the distance between adjacent pixel centers measured on the ground.

**Figure 3** shows the evolution of EO micro- and nano-satellite GSD in the last 20 years. The solid lines depict how the concepts of Medium Resolution (MR), High Resolution (HR), and Very High Resolution (VHR) evolved through time. While MR has maintained constant around 15 m, HR and VHR have decreased to 2 and 0.3 m, respectively.

Dots in **Figure 3** represent GSD values for the EO micro- and nano-satellites analyzed in this research (see Appendix A for details on the data analysis methodology). Cross marks prove that between 1999 and 2013 governmental and defense were almost the only micro- and nano-satellites devoted to obtaining HR and VHR images of the earth. However, 2013 marks a turning point in the EO market, with

**115**

and their high revisit time.

*Earth Observation Technologies: Low-End-Market Disruptive Innovation*

the irruption of private start-ups launching small space platforms able to achieve

*GSD, year of launching, mass, and revisit time of EO micro- and nano-satellites (own elaboration).*

Nano-satellites can obtain GSD below 3 m, thanks to new sensor technologies and the use of Low Earth Orbit and Very Low Earth Orbit (LEO and VLEO). In the range of micro-satellites, GSD around 1 m can be achieved, with perspectives of values even lower in the next years. These values are small enough to have a great interest for many commercial applications, mainly in the agriculture, transporta-

If the temporal resolution is also taken into account, micro- and nano-satellites show their huge potential for EO commercial applications. Satellite's revisit time is the time elapsed between observations of the same point on Earth's surface. **Figure 4** summarizes GSD, year of launching, mass, and revisit time of EO microand nano-satellites. The amount of satellites displayed in **Figure 4** is smaller than in **Figures 1** and **3** because the information about revisit time was not available for many satellites (see Appendix A for details on the data analysis methodology). Besides, revisit time of Flock (Planet) and ÑuSat (Satellogic) constellations is

In **Figure 4**, each circle represents a satellite or a constellation of identical satellites. GSD and launching year can be measured in both axes, while the circle gives information about the mass and revisit time (the bigger, the more massive and the darker, the shortest revisit time). Looking at the characteristics of different satellites, it is easy to see that Flock and the ÑuSat constellations are the only platforms able to provide revisit times lower than one day. This capability makes their data more appealing than any of the other platforms, even having a slightly less spatial resolution. The key for this performance is the possibility to design, launch, and operate constellations of more than 100 satellites, something which seems only possible, thanks to the reduced costs associated to micro- and nano-satellite technology considering the several hundred million dollar cost of traditional EO satellites. These massive micro- and nano-satellite constellations are aiming to transform EO imagery into a commercial product (e.g., analytical solutions from the big data obtained from the constellations), taking benefit of their almost high resolution

*DOI: http://dx.doi.org/10.5772/intechopen.90923*

resolutions from 4 to 1 m [15].

**Figure 4.**

tion, energy, and infrastructure markets [1].

calculated using their final future configuration.

**Figure 3.** *Evolution of EO satellite GSD during the period 1999–2018 (own elaboration).*

*Earth Observation Technologies: Low-End-Market Disruptive Innovation DOI: http://dx.doi.org/10.5772/intechopen.90923*

#### **Figure 4.**

*Satellites Missions and Technologies for Geosciences*

commercial and civil government applications.

0.3 m, respectively.

*growing and standardization has been proven as H1*.

*having an inferior performance than those of traditional EO spacecraft*.

**3.3 Hypothesis 3: micro- and nano-satellites performance**

distance between adjacent pixel centers measured on the ground.

*Evolution of EO satellite GSD during the period 1999–2018 (own elaboration).*

solutions using scientific and coarse resolution data, for example, pollution/aerosol monitoring and climate modeling. Many infrastructure applications for mapping also

In [1], it is also forecast that data also add to the belief that by making coarserresolution data free, the value-added services industry can leverage this to build greater value services with the potential for two very different businesses: a "highend" data market to support defense and free/low-cost data sources to support

*For these reasons, H2 would also be supported, since new market opportunities are* 

EO optical imaging satellite performance is defined in terms of spatial and temporal resolution. Spatial resolution relates to the level of detail obtained from an image and can be measured by the Ground Sample Distance (GSD), which is the

H3: *Micro- and nano-satellites improve their performance in a pace that meets EO market needs despite* 

**Figure 3** shows the evolution of EO micro- and nano-satellite GSD in the last 20 years. The solid lines depict how the concepts of Medium Resolution (MR), High Resolution (HR), and Very High Resolution (VHR) evolved through time. While MR has maintained constant around 15 m, HR and VHR have decreased to 2 and

Dots in **Figure 3** represent GSD values for the EO micro- and nano-satellites analyzed in this research (see Appendix A for details on the data analysis methodology). Cross marks prove that between 1999 and 2013 governmental and defense were almost the only micro- and nano-satellites devoted to obtaining HR and VHR images of the earth. However, 2013 marks a turning point in the EO market, with

can be developed by using Landsat and Sentinel data that are free of charge.

**114**

**Figure 3.**

*GSD, year of launching, mass, and revisit time of EO micro- and nano-satellites (own elaboration).*

the irruption of private start-ups launching small space platforms able to achieve resolutions from 4 to 1 m [15].

Nano-satellites can obtain GSD below 3 m, thanks to new sensor technologies and the use of Low Earth Orbit and Very Low Earth Orbit (LEO and VLEO). In the range of micro-satellites, GSD around 1 m can be achieved, with perspectives of values even lower in the next years. These values are small enough to have a great interest for many commercial applications, mainly in the agriculture, transportation, energy, and infrastructure markets [1].

If the temporal resolution is also taken into account, micro- and nano-satellites show their huge potential for EO commercial applications. Satellite's revisit time is the time elapsed between observations of the same point on Earth's surface. **Figure 4** summarizes GSD, year of launching, mass, and revisit time of EO microand nano-satellites. The amount of satellites displayed in **Figure 4** is smaller than in **Figures 1** and **3** because the information about revisit time was not available for many satellites (see Appendix A for details on the data analysis methodology). Besides, revisit time of Flock (Planet) and ÑuSat (Satellogic) constellations is calculated using their final future configuration.

In **Figure 4**, each circle represents a satellite or a constellation of identical satellites. GSD and launching year can be measured in both axes, while the circle gives information about the mass and revisit time (the bigger, the more massive and the darker, the shortest revisit time). Looking at the characteristics of different satellites, it is easy to see that Flock and the ÑuSat constellations are the only platforms able to provide revisit times lower than one day. This capability makes their data more appealing than any of the other platforms, even having a slightly less spatial resolution. The key for this performance is the possibility to design, launch, and operate constellations of more than 100 satellites, something which seems only possible, thanks to the reduced costs associated to micro- and nano-satellite technology considering the several hundred million dollar cost of traditional EO satellites. These massive micro- and nano-satellite constellations are aiming to transform EO imagery into a commercial product (e.g., analytical solutions from the big data obtained from the constellations), taking benefit of their almost high resolution and their high revisit time.

*For all these arguments, H3 would be supported, as performance is increasingly high in new satellites and constellations, whilst it is still far from conventional satellites*.

#### **3.4 Hypothesis 4: affordability of the new space technologies for EO**

H4: *Traditional, established space companies are ignoring the market due to very low-profit margins. This fact leaves room for new entrants with totally different business models. These new actors bet on low-cost technology to produce more affordable space systems for Earth Observation*.

During the last decades of the twentieth century, EO systems were mainly dedicated platforms owned and operated by public organizations or governments, often at a national level. This status quo was sustained by economic and policy barriers to space commerce. Traditionally, costs associated with satellite development and operation have been extremely high, both at LEO and Geostationary Orbits (GSO). However, platform standardization, continued progress in technology miniaturization, and Components Off-The-Shelf (COTS) are not only leading to cheaper satellite development and launch but also reducing manufacturing time. The possibility of using many small satellites in a constellation is enabling near real-time Earth Observation and addressing the issue of temporal resolution. Consequently, increasingly large amounts of data are being gathered every day.

This novel combination of price reduction and data generation has created in the last decade new business opportunities favoring the emergence of new space companies dedicated to the EO market. These companies base their innovative business models on the generation of near real-time high-resolution images (close to 1 m [15]) that are sold in user-oriented data access platforms (around \$1/km<sup>2</sup> [15]).

It is important to note that this new model is mainly ruled by start-ups with substantial investment capacity. **Figure 5** depicts the evolution of investment and the number of start-ups founded in the EO market between 2013 and 2017. It can be seen that almost 60 EO companies were funded in these 5 years. More significantly, the solid line clearly shows an increase in the investment, from less than 5 million

**Figure 5.**

*Earth Observation start-ups and investments during the period 2013–2017 (source [15] and own elaboration).*

**117**

*Earth Observation Technologies: Low-End-Market Disruptive Innovation*

Satellogic, PLD Space, Deimos, and GomSpace, among others [2, 5].

**3.5 Hypothesis 5: forms of ownership and operability of EO systems**

*operability of EO systems, which were formerly owned by governments or public organizations*.

technology without interrupting the innovation freedom of the space sector.

data analysis that represents VAS to commercial and public organizations.

dollars in 2013 and 2014 to almost 160 million dollars in 2017. According to [15], one of the reasons why new start-ups have been so successful in raising capital may well be because it challenges traditional space enterprises at technology implementation, deployment of spacecraft, innovation in the business model, etc. Some of these new start-ups that embrace open-innovation and knowledge sharing are Planet,

*For all these reasons, H4 would be supported, since new dealers in the space sector are* 

These new opportunities foster innovation and commercial growth, but they also leave room to establish a legal framework. That regulation would aim to maintain a safe and predictable space environment that allows us to face correctly the rapid changes of

H5: *Recent evolutions in micro- and nano-satellite technologies are affecting the forms of ownership and* 

The disruption in the space market extends the technological improvements. For instance, an increment in the supply of EO imagery would have implications for new business models, lower costs and more flexible ownership models for commer-

Emerging start-ups and spin-offs in the space sector are transforming the operability of EO systems owned by governments or public organizations. This transformation extends from the satellites themselves to the data processing and finally the

The idea of a "sharing economy" implies a revolution in the ownership of space imagery. All users have access to relevant and free data under a distributed ownership scheme. This trend is being driven by multiple technological innovations, for example, reusable launchers (e.g., SpaceX), online platforms where users can combine different data (e.g., Blacksky), or launcher service platform (e.g., Spaceflight). Nevertheless, there are questions over the sustainability of this ownership model, especially for commercial organizations that need to generate profit. Additionally, there are certain applications related to security or defense where such a shared-

Radiant Earth Foundation is trying to address some of these challenges, such as building a place where the development community can go for earth imagery and geospatial data and with access to market analytics, best practices guides, return of

*For all these reasons, H5 would also be supported, since new dealers from H4 are also* 

Although nano- and micro-satellites are dramatically changing the EO market, it cannot be said that they are providing novel products or services to the final data users. Satellite imaging has been used since the early 1970s when the Landsat program started. As stated before, the irruption of new start-ups with novel business

H6: *Micro- and nano-satellite missions offer disruptive functionalities that provide novel products or services* 

*DOI: http://dx.doi.org/10.5772/intechopen.90923*

*mainly new companies rather than stablished ones*.

ownership model may not be appropriate.

*defining new forms of ownership and service*.

**3.6 Hypothesis 6: disruptive functionality**

investment methodologies, and discussion of policy issues.

*that were unthinkable or impossible with traditional spacecraft missions*.

cializing imagery.

*Earth Observation Technologies: Low-End-Market Disruptive Innovation DOI: http://dx.doi.org/10.5772/intechopen.90923*

*Satellites Missions and Technologies for Geosciences*

*ogy to produce more affordable space systems for Earth Observation*.

*For all these arguments, H3 would be supported, as performance is increasingly high* 

During the last decades of the twentieth century, EO systems were mainly dedicated platforms owned and operated by public organizations or governments, often at a national level. This status quo was sustained by economic and policy barriers to space commerce. Traditionally, costs associated with satellite development and operation have been extremely high, both at LEO and Geostationary Orbits (GSO). However, platform standardization, continued progress in technology miniaturization, and Components Off-The-Shelf (COTS) are not only leading to cheaper satellite development and launch but also reducing manufacturing time. The possibility of using many small satellites in a constellation is enabling near real-time Earth Observation and addressing the issue of temporal resolution. Consequently,

H4: *Traditional, established space companies are ignoring the market due to very low-profit margins. This fact leaves room for new entrants with totally different business models. These new actors bet on low-cost technol-*

This novel combination of price reduction and data generation has created in the last decade new business opportunities favoring the emergence of new space companies dedicated to the EO market. These companies base their innovative business models on the generation of near real-time high-resolution images (close to 1 m [15]) that are sold in user-oriented data access platforms (around

It is important to note that this new model is mainly ruled by start-ups with substantial investment capacity. **Figure 5** depicts the evolution of investment and the number of start-ups founded in the EO market between 2013 and 2017. It can be seen that almost 60 EO companies were funded in these 5 years. More significantly, the solid line clearly shows an increase in the investment, from less than 5 million

*Earth Observation start-ups and investments during the period 2013–2017 (source [15] and own elaboration).*

*in new satellites and constellations, whilst it is still far from conventional satellites*.

**3.4 Hypothesis 4: affordability of the new space technologies for EO**

increasingly large amounts of data are being gathered every day.

**116**

**Figure 5.**

\$1/km<sup>2</sup>

[15]).

dollars in 2013 and 2014 to almost 160 million dollars in 2017. According to [15], one of the reasons why new start-ups have been so successful in raising capital may well be because it challenges traditional space enterprises at technology implementation, deployment of spacecraft, innovation in the business model, etc. Some of these new start-ups that embrace open-innovation and knowledge sharing are Planet, Satellogic, PLD Space, Deimos, and GomSpace, among others [2, 5].

*For all these reasons, H4 would be supported, since new dealers in the space sector are mainly new companies rather than stablished ones*.

#### **3.5 Hypothesis 5: forms of ownership and operability of EO systems**

H5: *Recent evolutions in micro- and nano-satellite technologies are affecting the forms of ownership and operability of EO systems, which were formerly owned by governments or public organizations*.

These new opportunities foster innovation and commercial growth, but they also leave room to establish a legal framework. That regulation would aim to maintain a safe and predictable space environment that allows us to face correctly the rapid changes of technology without interrupting the innovation freedom of the space sector.

The disruption in the space market extends the technological improvements. For instance, an increment in the supply of EO imagery would have implications for new business models, lower costs and more flexible ownership models for commercializing imagery.

Emerging start-ups and spin-offs in the space sector are transforming the operability of EO systems owned by governments or public organizations. This transformation extends from the satellites themselves to the data processing and finally the data analysis that represents VAS to commercial and public organizations.

The idea of a "sharing economy" implies a revolution in the ownership of space imagery. All users have access to relevant and free data under a distributed ownership scheme. This trend is being driven by multiple technological innovations, for example, reusable launchers (e.g., SpaceX), online platforms where users can combine different data (e.g., Blacksky), or launcher service platform (e.g., Spaceflight). Nevertheless, there are questions over the sustainability of this ownership model, especially for commercial organizations that need to generate profit. Additionally, there are certain applications related to security or defense where such a sharedownership model may not be appropriate.

Radiant Earth Foundation is trying to address some of these challenges, such as building a place where the development community can go for earth imagery and geospatial data and with access to market analytics, best practices guides, return of investment methodologies, and discussion of policy issues.

*For all these reasons, H5 would also be supported, since new dealers from H4 are also defining new forms of ownership and service*.

#### **3.6 Hypothesis 6: disruptive functionality**

H6: *Micro- and nano-satellite missions offer disruptive functionalities that provide novel products or services that were unthinkable or impossible with traditional spacecraft missions*.

Although nano- and micro-satellites are dramatically changing the EO market, it cannot be said that they are providing novel products or services to the final data users. Satellite imaging has been used since the early 1970s when the Landsat program started. As stated before, the irruption of new start-ups with novel business

models is not based on the generation of new data, but on the accessibility to it and complementing traditional space business models.

Therefore, considering that hypothesis 2 and 4 proved to be true, micro- and nano-satellites in the EO market can be categorized as low-end-market disruptive innovations. This hypothesis is also supported in [15], in which it is stated that new space business models do not drastically change satellite EO business, since both fulfill a similar kind of customer needs. What New Space businesses provide against traditional ones are accessibility, affordability, and commercialization of space products or services to commercial and noncommercial companies.

*H6 is therefore not fulfilled*.

#### **4. Conclusions**

New Space has usually been considered as a disruptive market. Some technological drivers like low-cost, high-quality image, among others, promote innovation, and they encourage new companies to develop new business models that make space more accessible and affordable for nongovernmental organizations on shorter development periods.

This chapter is measuring how disruptive the micro- and nano-satellite innovations are within the EO space market, under a series of hypotheses based on established standards for disruptive innovation [2, 5, 7, 8].

As a result, we have observed that micro- and nano-satellite technologies represent a low-end-market disruptive innovation, since they standardize the production process that reduces the cost of design and manufacturing phases. Additionally, thanks to this standardization, the forms of ownership and operability of EO platforms have changed to a private model. This allows the establishment of lower prices and creation of innovative services that not only open new market opportunities for new business models and data accessibility by commercial companies, but also improve the space market performance even though they have inferior characteristics than those provided by traditional EO spacecraft. As a consequence of all this, it cannot be said that micro- and nano-satellites drastically change satellite EO business, but they provide an accessible and affordable data to commercial and noncommercial companies against traditional ones.

#### **Acknowledgements**

The DISCOVERER project has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 737183.

#### **Appendix: quantitative data analysis**

Most of the data analyzed in this paper were obtained from the Union of Concerned Scientists (UCS) database [1]. This Web includes a listing of nearly 2000 operational satellites orbiting around Earth. Based on this information, only satellites with Earth Observation purposes were selected, which lead to a final number of 394 EO satellites usable for our research. From all these, **Figures 3** and **4** only picture information about those with spatial and temporal resolution values available. The list of used data can be found in **Table 4**.

**119**

*\**

**Table 4.**

*Earth Observation Technologies: Low-End-Market Disruptive Innovation*

**Name User Launch date Launch mass** 

DLR Tubsat Government 26/05/1999 45 6 — IKONOS-2 Commercial 24/09/1999 817 1 2.25 Terra Government 18/12/1999 4864 15 — QuickBird-2 Commercial 01/10/2001 1100 0.5 7 Bird 2 Government 22/10/2001 92 25 — SPOT-5 Government 04/05/2002 3030 2.5 26 BeijinGalaxy-1 Civil 27/10/2005 50 39 — EROS B1 Military/commercial 25/04/2006 350 0.7 —

GeoEye-1 Commercial 01/09/2008 1955 0.5 3 HJ-1 Government 05/09/2008 470 30 — Saudisat-2 Government 29/07/2009 35 15 — DEIMOS-1 Government 29/07/2009 90 22 2 Worldview-2 Commercial 01/10/2009 2800 0.5 2.4 Alsat Government 12/07/2010\* 116 2.5 —

Landsat-8 Government 11/02/2013 2623 15 — DubaiSat-2 Government 21/11/2013 300 1 —

Rising-2 Civil 24/05/2014 41 5 — Flock Constellation Commercial 19/06/2014\* 5 4 1 Aurora Commercial 19/06/2014 25 15 — Worldview-3 Commercial 01/08/2014 2800 0.4 2.75 ASNARO 1 Government 06/11/2014 500 0.5 — CBNT-1 Commercial 10/07/2015 91 1,5 — DMC 3 Commercial 10/07/2015\* 447 1 — LAPAN A2 Government 24/09/2015 68 5 — Bison Sat Civil 08/10/2015 1 43 — Athenoxat-1 Commercial 16/12/2015 6 25 — BIROS Government 22/06/2016 110 42.4 —

Worldview-4 Commercial 01/11/2016 2485 0.3 4.5 CE-SAT-1 Commercial 22/06/2017 50 1 — Skysat Commercial 31/10/2017\* 110 0.9 —

*Constellation's launch date stated in the table corresponds to the first launching.*

*List of satellites used in Figures 3 and 4 [3, 16–19].*

BKA 2 Government 22/07/2012 473 2.1

**(kg)**

Commercial 29/08/2008\* 175 6.5 3.25

Commercial 26/04/2014\* 90 10 5

Commercial 26/09/2016 44 1 —

**GSD (m)**

**Revisit time (days)**

*DOI: http://dx.doi.org/10.5772/intechopen.90923*

RapidEye Constellation

Zhuhai 1 Constellation

BlackSky Pathfinder


#### *Earth Observation Technologies: Low-End-Market Disruptive Innovation DOI: http://dx.doi.org/10.5772/intechopen.90923*

*Satellites Missions and Technologies for Geosciences*

*H6 is therefore not fulfilled*.

**4. Conclusions**

development periods.

**Acknowledgements**

complementing traditional space business models.

lished standards for disruptive innovation [2, 5, 7, 8].

noncommercial companies against traditional ones.

**Appendix: quantitative data analysis**

list of used data can be found in **Table 4**.

models is not based on the generation of new data, but on the accessibility to it and

Therefore, considering that hypothesis 2 and 4 proved to be true, micro- and nano-satellites in the EO market can be categorized as low-end-market disruptive innovations. This hypothesis is also supported in [15], in which it is stated that new space business models do not drastically change satellite EO business, since both fulfill a similar kind of customer needs. What New Space businesses provide against traditional ones are accessibility, affordability, and commercialization of space

New Space has usually been considered as a disruptive market. Some technological drivers like low-cost, high-quality image, among others, promote innovation, and they encourage new companies to develop new business models that make space more accessible and affordable for nongovernmental organizations on shorter

This chapter is measuring how disruptive the micro- and nano-satellite innovations are within the EO space market, under a series of hypotheses based on estab-

As a result, we have observed that micro- and nano-satellite technologies represent a low-end-market disruptive innovation, since they standardize the production process that reduces the cost of design and manufacturing phases. Additionally, thanks to this standardization, the forms of ownership and operability of EO platforms have changed to a private model. This allows the establishment of lower prices and creation of innovative services that not only open new market opportunities for new business models and data accessibility by commercial companies, but also improve the space market performance even though they have inferior characteristics than those provided by traditional EO spacecraft. As a consequence of all this, it cannot be said that micro- and nano-satellites drastically change satellite EO business, but they provide an accessible and affordable data to commercial and

The DISCOVERER project has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 737183.

Most of the data analyzed in this paper were obtained from the Union of Concerned Scientists (UCS) database [1]. This Web includes a listing of nearly 2000 operational satellites orbiting around Earth. Based on this information, only satellites with Earth Observation purposes were selected, which lead to a final number of 394 EO satellites usable for our research. From all these, **Figures 3** and **4** only picture information about those with spatial and temporal resolution values available. The

products or services to commercial and noncommercial companies.

**118**

#### **Table 4.**

*List of satellites used in Figures 3 and 4 [3, 16–19].*

### **Author details**

Silvia Rodriguez-Donaire1 , Miquel Sureda1 , Daniel Garcia-Almiñana1 \*, Eloi Sierra1 , Jose S. Perez2 , Peter C.E. Roberts3 , Jonathan Becedas4 , Georg H. Herdrich<sup>5</sup> , Dhiren Kataria6 , Ronald Outlaw7 , Leonardo Ghizoni8 , Rachel Villain2 , Alexis Conte2 , Badia Belkouchi2 , Kate Smith3 , Steve Edmondson3 , Sarah Haigh3 , Nicholas H. Crisp3 , Vitor T.A. Oiko3 , Rachel E. Lyons3 , Stephen D. Worral3 , Sabrina Livadiotti3 , Claire Huyton3 , Luciana A. Sinpetru3 , Rosa M. Domínguez4 , David González4 , Francesco Romano5 , Yung-An Chan5 , Adam Boxberger<sup>5</sup> , Stefanos Fasoulas5 , Constantin Traub5 , Victor Jungnell8 , Kristian Bay8 , Jonas Morsbøl8 , Ameli Schwalber<sup>9</sup> and Barbara Heißerer<sup>9</sup>


\*Address all correspondence to: daniel.garcia@upc.edu

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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*Earth Observation Technologies: Low-End-Market Disruptive Innovation*

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*DOI: http://dx.doi.org/10.5772/intechopen.90923*

[1] Perez S et al. Prospects of Earth Observation Overview. Euroconsult. DISCOVERER H2020 Deliverable; 2018

[2] Denis G, Claverie A, Pasco X, Darnis J, de Maupeou B, Lafaye M, et al. Towards disruptions in Earth observation? New Earth Observation systems and markets evolution: Possible scenarios and impacts. Acta Astronautica. 2017;**137**:415-433. DOI: 10.1016/j.actaastro.2017.04.034

[3] UCS Satellite Database [Internet]. Union of Concerned Scientists. 2019. Available from: https://www.ucsusa. org/nuclear-weapons/space-weapons/ satellite-database [Accessed: 13 May 2019]

[4] Kramer H. Observation of the Earth and Its Environment. Berlin: Springer;

[5] Summerer L. Signs of potentially disruptive innovation in the space sector. International Journal of

Innovation Science. 2011;**3**(3):127-140.

DOI: 10.1260/1757-2223.3.3.127

[6] Christensen C. The Innovator's Dilemma. New York, NY: Harper

[7] Christensen C, Raynor M. The Innovator's Solution: Creating and Sustaining Successful Growth. 1st ed. Boston: Harvard Business Review Press;

[8] Nagy D, Schuessler J, Dubinsky A. Defining and identifying disruptive innovations. Industrial Marketing Management. 2016;**57**:119-126. DOI: 10.1016/j.indmarman.2015.11.017

[9] Rogers E. Diffusion of Innovations. 4th ed. New York: Free Press; 1995

organizations. Management Science.

[10] Swanson E. Information systems innovation among

**References**

2002

Business; 2011

2013

*Earth Observation Technologies: Low-End-Market Disruptive Innovation DOI: http://dx.doi.org/10.5772/intechopen.90923*

#### **References**

*Satellites Missions and Technologies for Geosciences*

**Author details**

Jose S. Perez2

Alexis Conte2

Dhiren Kataria6

Nicholas H. Crisp3

Sabrina Livadiotti3

David González4

Jonas Morsbøl8

Stefanos Fasoulas5

2 Euroconsult, Paris, France

Silvia Rodriguez-Donaire1

, Peter C.E. Roberts3

, Badia Belkouchi2

, Ronald Outlaw7

, Ameli Schwalber<sup>9</sup>

, Vitor T.A. Oiko3

, Claire Huyton3

, Francesco Romano5

, Constantin Traub5

1 UPC-BarcelonaTECH ESEIAAT, Terrassa, Barcelona, Spain

3 The University of Manchester, Manchester, United Kingdom

5 Institute of Space System, University of Stuttgart, Stuttgart, Germany

6 Mullard Space Science Laboratory (UCL), Dorking, United Kingdom

9 Concentris Research Management GmbH, Fürstenfeldbruck, Germany

7 Christopher Newport University, Newport News, VA, United States of America

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

4 Elecnor Deimos Satellite Systems, Puertollano, Spain

\*Address all correspondence to: daniel.garcia@upc.edu

8 Gomspace AS, Aalborg East, Denmark

provided the original work is properly cited.

, Miquel Sureda1

, Jonathan Becedas4

, Leonardo Ghizoni8

, Rachel E. Lyons3

, Luciana A. Sinpetru3

, Yung-An Chan5

, Victor Jungnell8

and Barbara Heißerer<sup>9</sup>

, Kate Smith3

, Daniel Garcia-Almiñana1

, Steve Edmondson3

, Georg H. Herdrich<sup>5</sup>

, Stephen D. Worral3

, Adam Boxberger<sup>5</sup>

, Kristian Bay8

, Rachel Villain2

\*, Eloi Sierra1

,

,

,

,

, Rosa M. Domínguez<sup>4</sup>

,

, Sarah Haigh3

,

,

,

**120**

[1] Perez S et al. Prospects of Earth Observation Overview. Euroconsult. DISCOVERER H2020 Deliverable; 2018

[2] Denis G, Claverie A, Pasco X, Darnis J, de Maupeou B, Lafaye M, et al. Towards disruptions in Earth observation? New Earth Observation systems and markets evolution: Possible scenarios and impacts. Acta Astronautica. 2017;**137**:415-433. DOI: 10.1016/j.actaastro.2017.04.034

[3] UCS Satellite Database [Internet]. Union of Concerned Scientists. 2019. Available from: https://www.ucsusa. org/nuclear-weapons/space-weapons/ satellite-database [Accessed: 13 May 2019]

[4] Kramer H. Observation of the Earth and Its Environment. Berlin: Springer; 2002

[5] Summerer L. Signs of potentially disruptive innovation in the space sector. International Journal of Innovation Science. 2011;**3**(3):127-140. DOI: 10.1260/1757-2223.3.3.127

[6] Christensen C. The Innovator's Dilemma. New York, NY: Harper Business; 2011

[7] Christensen C, Raynor M. The Innovator's Solution: Creating and Sustaining Successful Growth. 1st ed. Boston: Harvard Business Review Press; 2013

[8] Nagy D, Schuessler J, Dubinsky A. Defining and identifying disruptive innovations. Industrial Marketing Management. 2016;**57**:119-126. DOI: 10.1016/j.indmarman.2015.11.017

[9] Rogers E. Diffusion of Innovations. 4th ed. New York: Free Press; 1995

[10] Swanson E. Information systems innovation among organizations. Management Science. 1994;**40**(9):1069-1092. DOI: 10.1287/ mnsc.40.9.1069

[11] Merges R, Reynolds G. The proper scope of the copyright and patent power. Harvard Journal on Legislation. 2000;**37**:45

[12] Abernathy WJ, Utterback JM. Patterns of industrial innovation. Technology Review. 1978;**80**:40-47

[13] Anderson P, Tushman M. Technological discontinuities and dominant designs: A cyclical model of technological change. Administrative Science Quarterly. 1990;**35**(4):604. DOI: 10.2307/2393511

[14] Dahlin K, Behrens D. When is an invention really radical? Research Policy. 2005;**34**(5):717-737. DOI: 10.1016/j. respol.2005.03.009

[15] Nagendra N, Segert T. Challenges for new space commercial earth observation small satellites. New Space. 2017;**5**(4):238-243. DOI: 10.1089/ space.2017.0014

[16] EO Portal Directory [Online]. EO Sharing Earth Observation Resources. Available from: https://directory. eoportal.org/web/eoportal/satellitemissions [Accessed: 19 May 2019]

[17] Planet SA [Online]. California: Planet Labs. 2019. Available from: https://www.planet.com/ [Accessed: 19 May 2019]

[18] Digital Globe SA [Online]. Westminster: DigitalGlobe Headquarters. 2019. Available from: https://www.digitalglobe.com/ [Accessed: 19 May 2019]

[19] Satellite Imaging Corporation [Online]. Houston: Satellite Imaging Corporation Headquarters. 2019. Available from: https://www.satimagingcorp.com/ [Accessed: 19 May 2019]

**123**

**Chapter 8**

**Abstract**

**1. Introduction**

space missions are:

A Survey on Small Satellite

for Geodetic Applications

*Vaios Lappas and Vassilis Kostopoulos*

enhance our knowledge in the geodetic field.

**Keywords:** small satellites, GPS, geodetic, space missions

ments of microwave signals emitted by artificial satellites [1–4].

Technologies and Space Missions

Advances in microelectronics, materials, combined with affordable and frequent launch opportunities has led to a revolution which consists of small satellite missions used for technology validation, Earth observation, space exploration. Small satellites are now being developed in large volumes for mega-constellations for Earth observation, Internet of Things (IoT) and low latency communications (internet) thus democratizing space and making new space applications a reality. Advances in small satellite platforms, miniaturization of instruments and the availability of low-cost launches for small satellites, can enable new, geodetic missions which can benefit from the use of constellations of small satellites. An overview of some of the most important small satellite based geodetic missions is presented, along with a brief overview of new mission concepts which can significantly

Today, space geodetic techniques are the primary tools to study size, figure and deformation of the Earth, and its motion as a finite body in the inertial reference system. Space geodetic techniques have become the fundamental tools for geodesy, geodetic astronomy, and geodynamics. The development of space geodesy has increase significantly with the progress in space technology, miniaturization of satellites and the advent of Global Navigation Satellite Systems (GNSS) and GNSS technology such as receivers. GNSS is making a much greater impact in the last decade with the advent of small satellites, launch availability and the miniaturization of electronics. It should be viewed as the replacement of classical navigation and positioning (based on the observation of astrometric positions of natural celestial objects) by measure-

With respect to space technology, the two main areas of geodetic research and

(Challenging Minisatellite Payload for Geophysical Research and Application)

• Gravity space missions: For geodesy and geodynamics, the CHAMP

and CHAMP-FO missions, the GRACE (Gravity Recovery and Climate Experiment) mission, and the GOCE (Gravity field and Ocean Current

#### **Chapter 8**

## A Survey on Small Satellite Technologies and Space Missions for Geodetic Applications

*Vaios Lappas and Vassilis Kostopoulos*

#### **Abstract**

Advances in microelectronics, materials, combined with affordable and frequent launch opportunities has led to a revolution which consists of small satellite missions used for technology validation, Earth observation, space exploration. Small satellites are now being developed in large volumes for mega-constellations for Earth observation, Internet of Things (IoT) and low latency communications (internet) thus democratizing space and making new space applications a reality. Advances in small satellite platforms, miniaturization of instruments and the availability of low-cost launches for small satellites, can enable new, geodetic missions which can benefit from the use of constellations of small satellites. An overview of some of the most important small satellite based geodetic missions is presented, along with a brief overview of new mission concepts which can significantly enhance our knowledge in the geodetic field.

**Keywords:** small satellites, GPS, geodetic, space missions

#### **1. Introduction**

Today, space geodetic techniques are the primary tools to study size, figure and deformation of the Earth, and its motion as a finite body in the inertial reference system. Space geodetic techniques have become the fundamental tools for geodesy, geodetic astronomy, and geodynamics. The development of space geodesy has increase significantly with the progress in space technology, miniaturization of satellites and the advent of Global Navigation Satellite Systems (GNSS) and GNSS technology such as receivers. GNSS is making a much greater impact in the last decade with the advent of small satellites, launch availability and the miniaturization of electronics. It should be viewed as the replacement of classical navigation and positioning (based on the observation of astrometric positions of natural celestial objects) by measurements of microwave signals emitted by artificial satellites [1–4].

With respect to space technology, the two main areas of geodetic research and space missions are:

• Gravity space missions: For geodesy and geodynamics, the CHAMP (Challenging Minisatellite Payload for Geophysical Research and Application) and CHAMP-FO missions, the GRACE (Gravity Recovery and Climate Experiment) mission, and the GOCE (Gravity field and Ocean Current

Explorer) mission are particularly fascinating. Our knowledge of the Earth's gravity field (thanks to the use of space-borne GPS receivers, accelerometers, and gradiometers) has significantly grown thanks to these missions. Gravity missions are of central importance for altimetry, because the precise geoids are required to refer the sea surface topography to the geoid [1].

• GNSS. GNSS stands for Global Navigation Satellite System. The current generation of GNSS may be viewed as the successor of the Doppler systems. The systems are based on coherent microwave signals (in the L-band) emitted by the satellites in (at least) two carrier frequencies. Simultaneity of measurement of the signals emitted by several satellites and recorded by a receiver allow for instantaneous positioning. The GPS (Global Positioning System) is probably the best known GNSS and is considered the best-known space geodetic technique today. The system has an impact on science and society as a whole, reaching far beyond space geodesy. GPS revolutionized surveying, timing, pedestrian, car, marine and aircraft navigation. Many millions of receivers are in use today. Space-borne applications of the GPS have a deep impact on geodesy and atmospheric sciences [1]. The development new GNSS systems from Europe (Galileo), China (Beidou) and others will bring new developments and substantially improve our knowledge of Earth's and planetary geodesy.

In summary, satellite geodetic missions offer the following capabilities:


The advent of microelectronics, miniaturization in combination with the proven use of commercial off the shelf (COTS) electronics, has led to the wide use of small satellites, i.e., spacecraft which have a mass of 500–1000 kg. Small satellites have proved to be an affordable means of demonstrating new technologies, but also allowing constellations of satellites to approach conventional space missions in a different manner by increasing the revisit time over multiple locations of interest, increase the number of scientific measurements but also enable the use of differential measurements using ranging techniques in combination with space-borne GPS receivers. The next section presents an introduction to small satellites followed by an overview of the most important geodetic small satellite missions in orbit or completed to date.

#### **2. Small satellites**

The size and cost of spacecraft vary depending on the application; some can hold in your hand while others like Hubble are as big as a school bus. Small spacecraft (smallsats) focus on spacecraft with a mass less than 180 kg and about the size

**125**

**Figure 1.**

*Nano/microsatellite (<50 kg) forecast.*

*A Survey on Small Satellite Technologies and Space Missions for Geodetic Applications*

of a large kitchen fridge. Even with small spacecraft, there is a large variety of size and mass that can be differentiated. The accepted small satellite classification

Small satellites, miniaturized satellites, or smallsats, are satellites of low mass and size, usually under 500 kg (1100 lb). While all such satellites can be referred to as "small", different classifications are used to categorize them based on mass. Satellites can be built small to reduce the large economic cost of launch vehicles and the costs associated with construction. Miniature satellites, especially in large numbers, may be more useful than fewer, larger ones for some purposes—for example, gathering of scientific data and radio relay. Small satellites have become a significant part of the space industry. The advent of small satellite technology in multiple areas such as micro-propulsion, cubesats, microelectronics, long distance communications and increased low cost rideshare launch availability has also led to new mission concepts and missions such as broadband internet, communications and Earth observation, which consist of mega constellations of small satellites. Given the available production capabilities of the Contractor and the trend of small satellites, seeking a demonstrator application in this market would be reasonable and would create market potential in the near future. The advent of microelectronics, electric micro propulsion and other small satellite subsystems has enabled a multitude of interplanetary and high power cubesat/nanosatellite mission to be

*DOI: http://dx.doi.org/10.5772/intechopen.92625*

• Minisatellite: 150–500 kg

• Microsatellite: 10–150 kg

• Nanosatellite: 1–10 kg

• Picosatellite: 0.01–1 kg

• Femtosatellite: 0.001–0.01 kg

(per kg) in the space community is as follows:

#### *A Survey on Small Satellite Technologies and Space Missions for Geodetic Applications DOI: http://dx.doi.org/10.5772/intechopen.92625*

of a large kitchen fridge. Even with small spacecraft, there is a large variety of size and mass that can be differentiated. The accepted small satellite classification (per kg) in the space community is as follows:

• Minisatellite: 150–500 kg

*Satellites Missions and Technologies for Geosciences*

by ground to satellite measurements

borne altimeters

**2. Small satellites**

Explorer) mission are particularly fascinating. Our knowledge of the Earth's gravity field (thanks to the use of space-borne GPS receivers, accelerometers, and gradiometers) has significantly grown thanks to these missions. Gravity missions are of central importance for altimetry, because the precise geoids are

• GNSS. GNSS stands for Global Navigation Satellite System. The current generation of GNSS may be viewed as the successor of the Doppler systems. The systems are based on coherent microwave signals (in the L-band) emitted by the satellites in (at least) two carrier frequencies. Simultaneity of measurement of the signals emitted by several satellites and recorded by a receiver allow for instantaneous positioning. The GPS (Global Positioning System) is probably the best known GNSS and is considered the best-known space geodetic technique today. The system has an impact on science and society as a whole, reaching far beyond space geodesy. GPS revolutionized surveying, timing, pedestrian, car, marine and aircraft navigation. Many millions of receivers are in use today. Space-borne applications of the GPS have a deep impact on geodesy and atmospheric sciences [1]. The development new GNSS systems from Europe (Galileo), China (Beidou) and others will bring new developments and

substantially improve our knowledge of Earth's and planetary geodesy.

1.Provide precise relative and geocentric locations of separated points on Earth

4.Provide measurements of time invariant and time variant aspects of vertical geometry of the oceans and land on a rapid and continuing basis by satellite-

The advent of microelectronics, miniaturization in combination with the proven use of commercial off the shelf (COTS) electronics, has led to the wide use of small satellites, i.e., spacecraft which have a mass of 500–1000 kg. Small satellites have proved to be an affordable means of demonstrating new technologies, but also allowing constellations of satellites to approach conventional space missions in a different manner by increasing the revisit time over multiple locations of interest, increase the number of scientific measurements but also enable the use of differential measurements using ranging techniques in combination with space-borne GPS receivers. The next section presents an introduction to small satellites followed by an overview of the most important geodetic small satellite missions in orbit or completed to date.

The size and cost of spacecraft vary depending on the application; some can hold in your hand while others like Hubble are as big as a school bus. Small spacecraft (smallsats) focus on spacecraft with a mass less than 180 kg and about the size

In summary, satellite geodetic missions offer the following capabilities:

2.Provide knowledge of the time invariant and time variant gravitational forces and surface forces acting on satellite from precise analysis of orbital

perturbations and by satellite borne gravity scanning devices

3.Provide precise geocentric location of a spacecraft

required to refer the sea surface topography to the geoid [1].

**124**


Small satellites, miniaturized satellites, or smallsats, are satellites of low mass and size, usually under 500 kg (1100 lb). While all such satellites can be referred to as "small", different classifications are used to categorize them based on mass. Satellites can be built small to reduce the large economic cost of launch vehicles and the costs associated with construction. Miniature satellites, especially in large numbers, may be more useful than fewer, larger ones for some purposes—for example, gathering of scientific data and radio relay. Small satellites have become a significant part of the space industry. The advent of small satellite technology in multiple areas such as micro-propulsion, cubesats, microelectronics, long distance communications and increased low cost rideshare launch availability has also led to new mission concepts and missions such as broadband internet, communications and Earth observation, which consist of mega constellations of small satellites. Given the available production capabilities of the Contractor and the trend of small satellites, seeking a demonstrator application in this market would be reasonable and would create market potential in the near future. The advent of microelectronics, electric micro propulsion and other small satellite subsystems has enabled a multitude of interplanetary and high power cubesat/nanosatellite mission to be

**Figure 1.** *Nano/microsatellite (<50 kg) forecast.*

**Figure 2.** *Microsatellite (<50 kg) constellations launched and planned.*


**127**

**Parameter** Platform mass (kg)

Payload mass (kg)

Dimensions (m)

Propulsion Lifetime (years)

**Table 2.** *Small satellite comparison (assembled from multiple sources).*

150

60 1 × 1 × 1.3 Xenon HET

>5

120 80 0.8 × 0.845 × 0.8

Multiple

>5

100

50 0.7 × 0.45 × 0.77

Resistojet

5

20

8 0.3 × 0.04 × 0.4

Multiple

5

**Airbus**

**OHB**

**SSTL**

**16**

**U**

*A Survey on Small Satellite Technologies and Space Missions for Geodetic Applications*

55

20

0.32 × 0.32 × 0.4

Multiple

3

*DOI: http://dx.doi.org/10.5772/intechopen.92625*

**SITAEL**

#### **Table 1.**

*Mega-constellations planned/operations (assembled from multiple sources).*


*A Survey on Small Satellite Technologies and Space Missions for Geodetic Applications DOI: http://dx.doi.org/10.5772/intechopen.92625*

#### **Table 2.**

*Small satellite comparison (assembled from multiple sources).*

*Satellites Missions and Technologies for Geosciences*

*Microsatellite (<50 kg) constellations launched and planned.*

Thales Alenia+ Orbital ATK

Boeing Satellite

Alenia

OneWeb Airbus JV

Thales Alenia (O3b) Boeing (O3bm)

*Mega-constellations planned/operations (assembled from multiple sources).*

66 + 9 spares

2956

LeoSat 78-108 Thales

1980

4425- 11,943

20 O3b 7 O3bm

**Con/n Num. Maker Weight Year Avail Orbit** 

**(km)**

860 kg 2009 2018 780 Complete

N/A 2016 N/A 1200 Unknown

1250 kg 2015 2022 1400 first

145 kg 2015 2020 1200 6 pilot

2014: O3b 2021: O3bm

SpaceX 227 kg 2015 2020 550 km 120

700 kg 2008:

117-512 TBC 300 kg 2016 2021 1000–

156 CASC <500 kg 2017 2022 160–

O3b 2017: O3bm

320 CASC < 500 kg 2017 2023 1100 Prototypes l

**Status**

launches in 2021

satellites in February 2019

launched in 2020

complete

Prototypes 2018

Prototypes 2018

2018

8000 O3b

1248

2000

**126**

**Table 1.**

**Figure 2.**

Iridium Next

SpaceX Starlink

O3b (SES)

Telesat LEO

CASIC Hongyun

CASC Hongyan

Boeing 1396-

OneWeb 882-

developed. JPL's MaRCO 3 U cubesat mission are operating already in Mars orbit as communication relays and the NASA funded LunarCube is a 100 W 3 U cubesat mission which will use a Busek iodine RF thruster for Lunar Exploration.

#### **2.1 Small satellite market and trends**

In addition to cubesats, larger small satellite missions are now being designed for high power missions due to the sophistication of their payloads and need to use micro electric propulsion which drive power demands. The smallsat (<500 kg mass satellites) market is going through significant expansion in terms of capabilities and demand. In the last couple of years, numerous companies have produced solutions, largely based around a constellation approach, to better deliver services and reach out to new users. These solutions are supported by new ventures, entrepreneurs investing in space in this so-called new or adaptive space environment. The logic of lower-cost constellations is to provide global connectivity from one system (satcom) or high-frequency change detection (in Earth observation [EO]) or connecting devices and vehicles (Information) for the Internet of Things (IoT), Machine to Machine (M2M), and traffic monitoring (AIS or ADS-B). It is aided by the advancement of satellite system miniaturization permitted by new technologies and/or advances in related sectors, particularly in computational technology with smallsats now providing operational services that were previously only achievable through heavier satellites. Over 300 nano/ microsatellites were launched in 2017, shattering analyst' expectations and surpassing even SpaceWorks "full market potential" prediction from last year. 2017 represented a 205% increase in nano/microsatellites launched compared to 2016. SpaceWorks' estimates up to 2600 nano/microsatellites will require launch over the next 5 years. This creates space for new opportunities that could benefit from the technology developments in the activity and match the size and scope of the involved partners.

As it can be seen in **Figures 1**, **2** and **Table 1**, mega-constellations with microsatellites up to a mass of 200–300 kg are the most popular trend in the space industry and indicate that the 200–300 kg mass and volume factor of 0.125–1 m3 are the near optimum to: (i) squeeze as many small satellites in medium size launch vehicles such as Falcon 9, Ariane 6 (ii) still launch 2–3 small satellites in dedicated small launchers VEGA, LauncherOne, Electron etc. (iii) are small enough to mass produce in lean, highly automated, automotive style production lines as OneWeb and SpaceX are currently undertaking.1

**Table 2** presents a summary and comparison of a representative selection of small satellites of different size, country of manufacture and capabilities.

#### **3. Small satellite geodetic missions**

Small satellites have significant benefits which have made them very popular in the last decade for scientific and commercial space missions:

• The advent of microelectronics, automated manufacturing, sensors, batteries, motors and the significant reduction in their cost of manufacture has enabled the miniaturization of larger conventional satellites and instruments brining the launch cost (cost per kg) significantly down

**129**

*A Survey on Small Satellite Technologies and Space Missions for Geodetic Applications*

• Use of COTS components for Low Earth Orbit (LEO) small satellite missions has also lowered space mission costs, helped towards miniaturization and also has created large availability of components and sensors which can be used for

• Miniaturized satellites such as cubesats or nano/microsatellites can be launched

• New private and civilian launchers have increased the number and competitiveness of launches, bringing launch costs down and increasing launch

• Access to private funding, entrepreneurship has increased small satellite subsystem, sensor and platform quantities and thus reducing mission costs

All the above advantages of small satellites have contributed to new space missions which were simply impossible, or too expensive to achieve in the past. Specifically for geodesy, there have been a number of scientifically rich satellite missions which used radar and laser altimetry as well as geodetical components to study Earth's gravity field such as CHAMP (CHAllenging Mini satellite Payload), GRACE (Gravity Recovery and Climate Experiment), and GOCE (Gravity field and steady-state Ocean Circulation Explorer). These satellite missions, although in the boundaries of small satellite missions (with respect to mass and cost) used small satellite technologies to achieve complex mission objectives and provide unique

• Miniature small satellites with low launch costs can enable constellations which can thus allow for a tremendous increase in the number, frequency and location

**Table 3** shows a summary of small satellite geodesy mission types. In summary, the benefits of small satellites geodetic missions are that they can be a cost effective means to measure/estimate Earth's geopotential using ranging and GPS data, while constellations can help get polar region data (missing), increase temporal frequency (from months to weeks) and increase the amount, frequency and location of science measurements at a reasonable mission cost. The following section describes

the most significant geodetic small satellite missions launched to date.

GFZ 1 (Geo Forschungs Zentrum Potsdam 1) is the first satellite mission designed and funded by the GeoForschungsZentrum Potsdam, Germany. The mission objectives of GFZ-1 were to determine variations in the rotational characteristics of the Earth and to measurement changes in the Earth's gravity field. For the high-resolution determination of the parameters of the gravity field the satellite had to be launched into the lowest possible orbit. At its altitude of 400 km, GFZ-1 was the lowest geodynamic satellite to be ranged to by lasers (in 1995). As the vehicle's orbit was decaying, the satellite's orbital motion was used to calculate atmospheric

GFZ-1 was s a passive geodetic satellite which only used one instrument, the retroreflector array (RRA). The GFZ-1 RRA consisted of 60 corner cubes and has a center of mass correction of 58 + 2 mm. These retroreflectors were quartz prisms placed in special holders recessed into the satellite's body. External metallic surfaces were covered with white paint for thermal control purposes and to facilitate visual

*DOI: http://dx.doi.org/10.5772/intechopen.92625*

science data about Earth's gravity field.

**3.1 Reflector type satellite missions**

densities [5, 6] (**Figure 3**).

space instruments, subsystems and platforms

as secondary payloads which are very affordable

availability significantly compared to 10 years ago

of sensor measurements simultaneously across the globe

<sup>1</sup> https://www.nanosats.eu/#figures

*A Survey on Small Satellite Technologies and Space Missions for Geodetic Applications DOI: http://dx.doi.org/10.5772/intechopen.92625*


All the above advantages of small satellites have contributed to new space missions which were simply impossible, or too expensive to achieve in the past. Specifically for geodesy, there have been a number of scientifically rich satellite missions which used radar and laser altimetry as well as geodetical components to study Earth's gravity field such as CHAMP (CHAllenging Mini satellite Payload), GRACE (Gravity Recovery and Climate Experiment), and GOCE (Gravity field and steady-state Ocean Circulation Explorer). These satellite missions, although in the boundaries of small satellite missions (with respect to mass and cost) used small satellite technologies to achieve complex mission objectives and provide unique science data about Earth's gravity field.

**Table 3** shows a summary of small satellite geodesy mission types. In summary, the benefits of small satellites geodetic missions are that they can be a cost effective means to measure/estimate Earth's geopotential using ranging and GPS data, while constellations can help get polar region data (missing), increase temporal frequency (from months to weeks) and increase the amount, frequency and location of science measurements at a reasonable mission cost. The following section describes the most significant geodetic small satellite missions launched to date.

#### **3.1 Reflector type satellite missions**

GFZ 1 (Geo Forschungs Zentrum Potsdam 1) is the first satellite mission designed and funded by the GeoForschungsZentrum Potsdam, Germany. The mission objectives of GFZ-1 were to determine variations in the rotational characteristics of the Earth and to measurement changes in the Earth's gravity field. For the high-resolution determination of the parameters of the gravity field the satellite had to be launched into the lowest possible orbit. At its altitude of 400 km, GFZ-1 was the lowest geodynamic satellite to be ranged to by lasers (in 1995). As the vehicle's orbit was decaying, the satellite's orbital motion was used to calculate atmospheric densities [5, 6] (**Figure 3**).

GFZ-1 was s a passive geodetic satellite which only used one instrument, the retroreflector array (RRA). The GFZ-1 RRA consisted of 60 corner cubes and has a center of mass correction of 58 + 2 mm. These retroreflectors were quartz prisms placed in special holders recessed into the satellite's body. External metallic surfaces were covered with white paint for thermal control purposes and to facilitate visual

*Satellites Missions and Technologies for Geosciences*

**2.1 Small satellite market and trends**

the involved partners.

SpaceX are currently undertaking.1

**3. Small satellite geodetic missions**

<sup>1</sup> https://www.nanosats.eu/#figures

developed. JPL's MaRCO 3 U cubesat mission are operating already in Mars orbit as communication relays and the NASA funded LunarCube is a 100 W 3 U cubesat

In addition to cubesats, larger small satellite missions are now being designed

As it can be seen in **Figures 1**, **2** and **Table 1**, mega-constellations with microsatellites up to a mass of 200–300 kg are the most popular trend in the space industry

are the near

and indicate that the 200–300 kg mass and volume factor of 0.125–1 m3

small satellites of different size, country of manufacture and capabilities.

the last decade for scientific and commercial space missions:

the launch cost (cost per kg) significantly down

optimum to: (i) squeeze as many small satellites in medium size launch vehicles such as Falcon 9, Ariane 6 (ii) still launch 2–3 small satellites in dedicated small launchers VEGA, LauncherOne, Electron etc. (iii) are small enough to mass produce in lean, highly automated, automotive style production lines as OneWeb and

**Table 2** presents a summary and comparison of a representative selection of

Small satellites have significant benefits which have made them very popular in

• The advent of microelectronics, automated manufacturing, sensors, batteries, motors and the significant reduction in their cost of manufacture has enabled the miniaturization of larger conventional satellites and instruments brining

for high power missions due to the sophistication of their payloads and need to use micro electric propulsion which drive power demands. The smallsat (<500 kg mass satellites) market is going through significant expansion in terms of capabilities and demand. In the last couple of years, numerous companies have produced solutions, largely based around a constellation approach, to better deliver services and reach out to new users. These solutions are supported by new ventures, entrepreneurs investing in space in this so-called new or adaptive space environment. The logic of lower-cost constellations is to provide global connectivity from one system (satcom) or high-frequency change detection (in Earth observation [EO]) or connecting devices and vehicles (Information) for the Internet of Things (IoT), Machine to Machine (M2M), and traffic monitoring (AIS or ADS-B). It is aided by the advancement of satellite system miniaturization permitted by new technologies and/or advances in related sectors, particularly in computational technology with smallsats now providing operational services that were previously only achievable through heavier satellites. Over 300 nano/ microsatellites were launched in 2017, shattering analyst' expectations and surpassing even SpaceWorks "full market potential" prediction from last year. 2017 represented a 205% increase in nano/microsatellites launched compared to 2016. SpaceWorks' estimates up to 2600 nano/microsatellites will require launch over the next 5 years. This creates space for new opportunities that could benefit from the technology developments in the activity and match the size and scope of

mission which will use a Busek iodine RF thruster for Lunar Exploration.

**128**


#### **Table 3.**

*Small satellite geodetic mission types with mission examples.*

#### **Figure 3.**

*Model of the geo research satellite GFZ-1 (GFZ) [6].*

observation in space. The satellite was built by Kayser Threde GmbH and launched through the space station MIR bby RKK Energiya and had a mass of 21 kg. GFZ-1 was transported to Mir Station aboard the Russian Progress-M 27 spacecraft and from there put into a low Earth orbit in April 1995 at an orbit of 382 km × 395 km with an inclination 51.6°. On June 23rd, 1999, GFZ-1 completed its mission with the satellite burning up in the Earth's upper atmosphere. The GFZ-1 orbited nearly 24,000 times around the Earth and for 4 years and 64 days in space, 5402 passes of GFZ-1 were observed by 33 cooperating ground stations using satellite laser ranging, around the globe [5, 6].

**131**

**Figure 4.**

*the measurement of frame dragging [8].*

*A Survey on Small Satellite Technologies and Space Missions for Geodetic Applications*

The LARES mission concept represents an improvement of the LAGEOS-3 project proposed in 1984 by Ciufolini. The LAGEOS (Laser Geodynamics Satellite) series was designed to be a passive long-lived satellite with a stable, well-defined orbit. As such, it acts as a reference point in inertial space. An international groundbased network of laser ranging stations used the orbiting LAGEOS satellites as passive reflectors to obtain ranges to the satellite by precision laser echo-bounce techniques. Since the position of the satellites is determined by some laser ranging stations with uncertainties of <1 cm, there was a potential for measuring the 2 m per year drift of the nodes of LAGEOS satellites in orbit. The LAGEOS-1 (LAser GEOdynamics Satellite-1, launch May 4, 1976) and LAGEOS-2 (launch Oct. 23, 1992) missions in MEO (Medium Earth Orbit) of NASA and ASI represented the origin of international cooperative research in geodynamics [7, 8] (**Figure 4**).

LARES was a completely passive satellite made of a dense tungsten alloy (THA-18 N) sphere of 376 mm in diameter and a mass of ~400 kg (density of ~18 kg/cm3

covered with retroreflectors that allowed the satellite's motion to be followed via SLR (Satellite Laser Ranging) from Earth. Once in orbit, LARES became the satellite with the highest mean density in the Solar System. The surface of the sphere was covered by 92 CCRs (Corner Cube Reflectors) evenly distributed so that the signal strength is practically independent on satellite attitude. The LARES spacecraft was launched on February 13, 2012 on the maiden flight of the Vega launch vehicle of ESA (the Vega flight was designated as VV01); the launch site was Kourou in French Guiana [7, 8]. Larets was a small geodesy and calibration satellite launched for IPIE (Institute

of Space Device Engineering—Moscow). It was a 21 cm sphere with 60 laser retro-reflectors, very similar to the German GFZ 1 satellite. Larets was designed to address scientific and applied problems in the interests of geodesy and geodynamics. The LARETS mission launched in 1003 with a 21 kg mass and in a 675 km orbit, was a next generation satellite based on a low-target-error laser satellite design optimization, which started with the WESTPAC mission, another reflector type satellite mission launched in 1998 in a 835 km, 98.67°. Larets was launched with a cluster of small satellites in September 2003 on a Kosmos-3M rocket [9] (**Figure 5**).

**3.2 Geodesy with GPS measurements of the Earth's gravitation field**

Challenging Minisatellite Payload (CHAMP) was a German satellite launched

July 15, 2000 from Plesetsk, Russia and was used for atmospheric and ionospheric research, as well as other geoscientific applications, such as GPS radio

*(Left) Image of LARES satellite (Right) Schematic view of LAGEOS-1, LAGEOS-2 and LARES in orbit for* 

)

*DOI: http://dx.doi.org/10.5772/intechopen.92625*

#### *A Survey on Small Satellite Technologies and Space Missions for Geodetic Applications DOI: http://dx.doi.org/10.5772/intechopen.92625*

The LARES mission concept represents an improvement of the LAGEOS-3 project proposed in 1984 by Ciufolini. The LAGEOS (Laser Geodynamics Satellite) series was designed to be a passive long-lived satellite with a stable, well-defined orbit. As such, it acts as a reference point in inertial space. An international groundbased network of laser ranging stations used the orbiting LAGEOS satellites as passive reflectors to obtain ranges to the satellite by precision laser echo-bounce techniques. Since the position of the satellites is determined by some laser ranging stations with uncertainties of <1 cm, there was a potential for measuring the 2 m per year drift of the nodes of LAGEOS satellites in orbit. The LAGEOS-1 (LAser GEOdynamics Satellite-1, launch May 4, 1976) and LAGEOS-2 (launch Oct. 23, 1992) missions in MEO (Medium Earth Orbit) of NASA and ASI represented the origin of international cooperative research in geodynamics [7, 8] (**Figure 4**).

LARES was a completely passive satellite made of a dense tungsten alloy (THA-18 N) sphere of 376 mm in diameter and a mass of ~400 kg (density of ~18 kg/cm3 ) covered with retroreflectors that allowed the satellite's motion to be followed via SLR (Satellite Laser Ranging) from Earth. Once in orbit, LARES became the satellite with the highest mean density in the Solar System. The surface of the sphere was covered by 92 CCRs (Corner Cube Reflectors) evenly distributed so that the signal strength is practically independent on satellite attitude. The LARES spacecraft was launched on February 13, 2012 on the maiden flight of the Vega launch vehicle of ESA (the Vega flight was designated as VV01); the launch site was Kourou in French Guiana [7, 8].

Larets was a small geodesy and calibration satellite launched for IPIE (Institute of Space Device Engineering—Moscow). It was a 21 cm sphere with 60 laser retro-reflectors, very similar to the German GFZ 1 satellite. Larets was designed to address scientific and applied problems in the interests of geodesy and geodynamics. The LARETS mission launched in 1003 with a 21 kg mass and in a 675 km orbit, was a next generation satellite based on a low-target-error laser satellite design optimization, which started with the WESTPAC mission, another reflector type satellite mission launched in 1998 in a 835 km, 98.67°. Larets was launched with a cluster of small satellites in September 2003 on a Kosmos-3M rocket [9] (**Figure 5**).

#### **3.2 Geodesy with GPS measurements of the Earth's gravitation field**

Challenging Minisatellite Payload (CHAMP) was a German satellite launched July 15, 2000 from Plesetsk, Russia and was used for atmospheric and ionospheric research, as well as other geoscientific applications, such as GPS radio

#### **Figure 4.**

*(Left) Image of LARES satellite (Right) Schematic view of LAGEOS-1, LAGEOS-2 and LARES in orbit for the measurement of frame dragging [8].*

*Satellites Missions and Technologies for Geosciences*

Geodesy: measurement of the Earth's gravitation

Geodesy by Differential measurement

Multipoint geodesy (constellation), Reflectometry

field

Geodesy with retroreflector array

**Mission Approach Example Notes**

(drag 0<sup>−</sup><sup>6</sup>

CHAMP (2000)

GRACE (2002) GRACE-FO (2010)

TDS-1, GYCNSS, C-2 Low cost mission with medium

Performance limited due to acceleration noise

Application to multiple fields

orbit determination/control

resolution data

GFZ-1, Larets Low resolution data

Cubesats Need high precision attitude/

1 satellite with accelerometer + GPS GPS: m accuracy Accelerometer: 10<sup>−</sup>10 m/s2

1 satellite with retroreflector array

2 satellites with accelerometers, GPS,

Ranging: nm to μm

Ranging: nm to μm

with ranging, GPS Accuracy: 10<sup>−</sup>10 to 10<sup>−</sup>15 m/s2 Drag force canceled

Satellites with accelerometers, GPS,

ranging

ranging

Drag-free based geodesy 2 drag-free satellites

*Small satellite geodetic mission types with mission examples.*

m/s2 )

**130**

**Figure 3.**

**Table 3.**

ing, around the globe [5, 6].

*Model of the geo research satellite GFZ-1 (GFZ) [6].*

observation in space. The satellite was built by Kayser Threde GmbH and launched through the space station MIR bby RKK Energiya and had a mass of 21 kg. GFZ-1 was transported to Mir Station aboard the Russian Progress-M 27 spacecraft and from there put into a low Earth orbit in April 1995 at an orbit of 382 km × 395 km with an inclination 51.6°. On June 23rd, 1999, GFZ-1 completed its mission with the satellite burning up in the Earth's upper atmosphere. The GFZ-1 orbited nearly 24,000 times around the Earth and for 4 years and 64 days in space, 5402 passes of GFZ-1 were observed by 33 cooperating ground stations using satellite laser rang-

**Figure 5.** *Larets satellite model [9].*

occultation. CHAMP was managed by GeoForschungsZentrum (GFZ) Potsdam (GFZ). The spacecraft was the first application of Astrium's "Flexbus" platform (now Airbus Defense and Space); GRACE was the second. A heavily modified version flew as the GOCE mission. CHAMP completed its mission and reentered the Earth's atmosphere on 19 September 2010 after 10 years (design life: 5 years) [10]. The three primary science objectives of the CHAMP mission were to provide:


With its multifunctional and complementary payload CHAMP aimed at contributing to the following Earth system components:


**133**

*A Survey on Small Satellite Technologies and Space Missions for Geodetic Applications*

The CHAMP satellite had a robust structure design with fixed solar panels. The primary structure was mainly based on aluminum sandwich panels with an additional kapton foam layer on the outer panels. The shape of the satellite was a compromise with respect to its aerodynamic behaviour, accommodation of instruments

and subsystems and fitting into the fairing of the launcher [10].

/kg

GRACE was an international cooperative US-German dual-minisatellite SST (Satellite-to-Satellite Tracking) geodetic mission with the overall objective to obtain long-term data with unprecedented accuracy for global (high-resolution) models of the mean and the time-variable components of the Earth's gravity field (a new model of the Earth's gravity field every 30 days for 5 years). GRACE was also part of NASA's ESSP (Earth System Science Pathfinder) program [11, 12]. The science

• To enable a better understanding of ocean surface currents and ocean heat

• To monitor changes in the storage of water and snow on the continents

• Length (with 4044 mm Boom): 8333 mm

*Front view of the CHAMP spacecraft (image credit: GFZ).*

• Area to mass ratio: 0.00138 m2

**3.3 Multipoint geodesy and Reflectometry**

• To measure changes in the sea-floor pressure

• To measure the mass balance of ice sheets and glaciers

• To study ocean mass changes

• Total mass: 522 kg

**Figure 6.**

• Height: 750 mm

• Width: 1621 mm

objectives were:

transport

*DOI: http://dx.doi.org/10.5772/intechopen.92625*

*A Survey on Small Satellite Technologies and Space Missions for Geodetic Applications DOI: http://dx.doi.org/10.5772/intechopen.92625*

**Figure 6.**

*Satellites Missions and Technologies for Geosciences*

occultation. CHAMP was managed by GeoForschungsZentrum (GFZ) Potsdam (GFZ). The spacecraft was the first application of Astrium's "Flexbus" platform (now Airbus Defense and Space); GRACE was the second. A heavily modified version flew as the GOCE mission. CHAMP completed its mission and reentered the Earth's atmosphere on 19 September 2010 after 10 years (design life: 5 years) [10]. The three primary science objectives of the CHAMP mission

• highly precise global long-wavelength features of the static Earth gravity field

• high accuracy global estimates of the main and crustal magnetic field of the

• large number of GPS signal refraction data, with a good global distribution, caused by the atmosphere and ionosphere, which can be converted into

With its multifunctional and complementary payload CHAMP aimed at

• Geosphere: investigation of the structure and dynamics of the solid Earth from the core along the mantle to the crust, and investigation of interactions with

• Hydrosphere: more accurate monitoring of ocean circulation, global sea level changes and short-term changes in the global water balance as well as interac-

• Atmosphere: global sounding of the vertical layers of the neutral and ionized gas shell of the Earth and relationship with weather on Earth and space

Earth and the space/time variability of these field components

**132**

were to provide:

*Larets satellite model [9].*

**Figure 5.**

and the temporal variation of this field.

temperature, water vapor and electron content.

contributing to the following Earth system components:

the ocean and atmosphere

weather (**Figure 6**).

tions with weather and climate

*Front view of the CHAMP spacecraft (image credit: GFZ).*

The CHAMP satellite had a robust structure design with fixed solar panels. The primary structure was mainly based on aluminum sandwich panels with an additional kapton foam layer on the outer panels. The shape of the satellite was a compromise with respect to its aerodynamic behaviour, accommodation of instruments and subsystems and fitting into the fairing of the launcher [10].


#### **3.3 Multipoint geodesy and Reflectometry**

GRACE was an international cooperative US-German dual-minisatellite SST (Satellite-to-Satellite Tracking) geodetic mission with the overall objective to obtain long-term data with unprecedented accuracy for global (high-resolution) models of the mean and the time-variable components of the Earth's gravity field (a new model of the Earth's gravity field every 30 days for 5 years). GRACE was also part of NASA's ESSP (Earth System Science Pathfinder) program [11, 12]. The science objectives were:


The mission concept made use of measurements of the inter-satellite range changes and its derivatives between two co-planar satellites (in low-altitude and polar orbits), using a microwave tracking system. The orbits of the two separately flying satellites are perturbed differently in the Earth's gravity field, leading to intersatellite range variations. In addition, each satellite carried a GPS receiver of geodetic quality and high-accuracy accelerometers to enable accurate orbit determination, spatial registration of gravity data and the estimation of gravity field models. The fluctuations in the strength of the Earth's gravity field reflect in turn changes in the distribution of mass in the ocean, atmosphere, and solid Earth, and in the storage of water, snow, and ice on land. Since ocean bottom pressure represents a column integral of the mass of the atmosphere plus ocean, this measurement technique permits the deduction of ocean bottom pressure changes from space [11, 12].

Both satellite structures were of identical design. The shape of each satellite is trapezoidal in cross section, based on the FLEXBUS design of Astrium (now Airbus Defense and Space) (length = 3122 mm, height = 720 mm, bottom width = 1942 mm, top width = 693 mm). The FLEXBUS structure consists of CFRP (Carbon Fiber Reinforced Plastic). This material, with a very low coefficient of thermal expansion, provides the dimensional stability necessary for precise range change measurements between the two spacecraft. The actuators include a cold gas system (with 12 attitude control thrusters and two orbit control thrusters, each rated at 40 mN) and three magnetorquers [11, 12] (**Figure 7**).

Each satellite has a mass of 432 kg (science payload = 40 kg, fuel = 34 kg) and the satellite power is 150-210 W (science payload = 75 W). The top and side panels of each satellite are covered with strings of silicon solar cells; NiH batteries with 16 Ah provide power storage. The satellite design life was 5 years. About 80% of the spacecraft's on-board electronics parts were COTS (Commercial Off-the-Shelf) products. Mission operations exceeded the initial 5 years, operating for 15 years until the decommissioning of GRACE-2 on 27 October 2017 [11, 12] (**Figure 8**).

Based on the significant success of GRACE, the GRACE-FO mission, is also a collaboration between NASA and GFZ and was launched on 22 May 2018 aboard a SpaceX Falcon 9 rocket from Vandenberg AFB, California, sharing the launch with five Iridium NEXT satellites [13]. During in-orbit checks, an anomaly was discovered in the primary system component of the microwave instrument (MWI), and the system was temporarily powered down on 19 July 2018. After a full investigation by an anomaly response team at JPL, the backup system in the MWI was powered up on 19 October 2018 and GRACE-FO resumed its in-orbit checks. GRACE-FO entered the science phase of its mission on 28 January 2019 [13]. The orbit and design of GRACE-FO is very similar to its predecessor. GRACE-FO has a design life of 5 years. Astrium (now Airbus DS) uses a 3rd generation Flexbus for the GRACE-FO mission. Each of the GRACE-FO satellites measures approximately

**135**

**Figure 9.**

*(GRACE-FO) twin satellites [13].*

*A Survey on Small Satellite Technologies and Space Missions for Geodetic Applications*

3 m × 2 m × 0.8 m and has a mass of around 580 kg. GRACE-FO employs the same two-way microwave-ranging link as GRACE, which will allow for similar inter-

*(Left) Artist concept of GRACE-FO Mission; (Right) the gravity recovery and climate experiment follow-on* 

In addition, GRACE-FO employs laser-ranging interferometry (LRI) as a technological experiment in preparation for future satellites. The LRI allows for more accurate inter-satellite ranging due to the shorter wavelength of light, and additionally allows the angle between the two spacecraft to be measured as well as their separation, via differential wavefront sensing. Using the LRI, scientists have improved the precision of the separation distance measurements by a factor of more than 20 relative to the GRACE mission. The LRL lasers must be detected by a spacecraft about 137 miles (220 km) away. This laser approach will generate much more accurate measurements than the previous GRACE satellite mission. The GRACE-FO satellites obtain electricity from gallium arsenide solar cell array panels covering the outside of each satellite. GRACE-FO will continue to monitor Earth's gravity and climate. The mission will track gravitational changes in global sea levels, glaciers, and ice sheets, as well as large lake and river water levels, and soil moisture. In addition, each of the satellites will use GPS antennas to create at least 200 profiles per day of atmospheric temperature distribution and water vapor content, a first for the

*DOI: http://dx.doi.org/10.5772/intechopen.92625*

satellite ranging precision (**Figure 9**).

*GRACE gravity field maps [11, 12].*

**Figure 8.**

GRACE mission [13].

**Figure 7.** *GRACE satellite design [11, 12].*

*A Survey on Small Satellite Technologies and Space Missions for Geodetic Applications DOI: http://dx.doi.org/10.5772/intechopen.92625*

**Figure 8.** *GRACE gravity field maps [11, 12].*

*Satellites Missions and Technologies for Geosciences*

The mission concept made use of measurements of the inter-satellite range changes and its derivatives between two co-planar satellites (in low-altitude and polar orbits), using a microwave tracking system. The orbits of the two separately flying satellites are perturbed differently in the Earth's gravity field, leading to intersatellite range variations. In addition, each satellite carried a GPS receiver of geodetic quality and high-accuracy accelerometers to enable accurate orbit determination, spatial registration of gravity data and the estimation of gravity field models. The fluctuations in the strength of the Earth's gravity field reflect in turn changes in the distribution of mass in the ocean, atmosphere, and solid Earth, and in the storage of water, snow, and ice on land. Since ocean bottom pressure represents a column integral of the mass of the atmosphere plus ocean, this measurement technique permits

the deduction of ocean bottom pressure changes from space [11, 12].

rated at 40 mN) and three magnetorquers [11, 12] (**Figure 7**).

Both satellite structures were of identical design. The shape of each satellite is trapezoidal in cross section, based on the FLEXBUS design of Astrium (now Airbus Defense and Space) (length = 3122 mm, height = 720 mm, bottom width = 1942 mm, top width = 693 mm). The FLEXBUS structure consists of CFRP (Carbon Fiber Reinforced Plastic). This material, with a very low coefficient of thermal expansion, provides the dimensional stability necessary for precise range change measurements between the two spacecraft. The actuators include a cold gas system (with 12 attitude control thrusters and two orbit control thrusters, each

Each satellite has a mass of 432 kg (science payload = 40 kg, fuel = 34 kg) and the satellite power is 150-210 W (science payload = 75 W). The top and side panels of each satellite are covered with strings of silicon solar cells; NiH batteries with 16 Ah provide power storage. The satellite design life was 5 years. About 80% of the spacecraft's on-board electronics parts were COTS (Commercial Off-the-Shelf) products. Mission operations exceeded the initial 5 years, operating for 15 years until the decommissioning of GRACE-2 on 27 October 2017 [11, 12] (**Figure 8**). Based on the significant success of GRACE, the GRACE-FO mission, is also a collaboration between NASA and GFZ and was launched on 22 May 2018 aboard a SpaceX Falcon 9 rocket from Vandenberg AFB, California, sharing the launch with five Iridium NEXT satellites [13]. During in-orbit checks, an anomaly was discovered in the primary system component of the microwave instrument

(MWI), and the system was temporarily powered down on 19 July 2018. After a full investigation by an anomaly response team at JPL, the backup system in the MWI was powered up on 19 October 2018 and GRACE-FO resumed its in-orbit checks. GRACE-FO entered the science phase of its mission on 28 January 2019 [13]. The orbit and design of GRACE-FO is very similar to its predecessor. GRACE-FO has a design life of 5 years. Astrium (now Airbus DS) uses a 3rd generation Flexbus for the GRACE-FO mission. Each of the GRACE-FO satellites measures approximately

**134**

**Figure 7.**

*GRACE satellite design [11, 12].*

3 m × 2 m × 0.8 m and has a mass of around 580 kg. GRACE-FO employs the same two-way microwave-ranging link as GRACE, which will allow for similar intersatellite ranging precision (**Figure 9**).

In addition, GRACE-FO employs laser-ranging interferometry (LRI) as a technological experiment in preparation for future satellites. The LRI allows for more accurate inter-satellite ranging due to the shorter wavelength of light, and additionally allows the angle between the two spacecraft to be measured as well as their separation, via differential wavefront sensing. Using the LRI, scientists have improved the precision of the separation distance measurements by a factor of more than 20 relative to the GRACE mission. The LRL lasers must be detected by a spacecraft about 137 miles (220 km) away. This laser approach will generate much more accurate measurements than the previous GRACE satellite mission. The GRACE-FO satellites obtain electricity from gallium arsenide solar cell array panels covering the outside of each satellite. GRACE-FO will continue to monitor Earth's gravity and climate. The mission will track gravitational changes in global sea levels, glaciers, and ice sheets, as well as large lake and river water levels, and soil moisture. In addition, each of the satellites will use GPS antennas to create at least 200 profiles per day of atmospheric temperature distribution and water vapor content, a first for the GRACE mission [13].

#### **Figure 9.**

*(Left) Artist concept of GRACE-FO Mission; (Right) the gravity recovery and climate experiment follow-on (GRACE-FO) twin satellites [13].*

#### *3.3.1 GNSS reflectometry*

GNSS-Reflectometry is a new technique that shows promise for many Earth observation applications including remote sensing of oceans, land, and ice. High grade GNSS payload has been developed in the last few years, that are low in size and power, and suitable for use on small satellites. One such GNSS payload is the SGR-ReSI GNSS Reflectometry Instrument flown on the TechDemoSat-1 microsatellite mission, launched in July 2014. The instrument has been operational since its commissioning in September 2014 and has been collecting delay Doppler maps routinely over many different surfaces. Preliminary work has been undertaken to develop and validate wind speed inversion algorithms against Advanced Scatterometer (ASCAT) wind measurements with promising results [14]. One of the first ever GPS Reflectometry experiments was flown again by Surrey Satellite Technology Limited on the UK-DMC microsatellite mission, launched in 2003, which proved the feasibility of using GNSS reflections for measuring the sea state and other geophysical observables through a partnership between SSTL and National Oceanography Centre (NOC) [14]. Preliminary work using UK-DMC GPS data focused on inverting the measurements into Level 2 products, specifically wind speed and mean-squared slope over the ocean, with promising results. Reflections recovered over the land surface showed a strong geophysical imprint, suggesting potential for hydrological and vegetation related retrieval. Subsequently, a new instrument was developed called the Space GNSS Receiver Remote Sensing Instrument (SGR-ReSI) to gather more space-borne reflectometry data and demonstrate the potential for a sea-state service. In parallel, a US mission called CYGNSS was selected by NASA that plans to measure hurricanes with reflected GNSS signals collected using an updated revision of the SGR-ReSI, (also referred to as delay Doppler mapping Instrument) as payload on each of the eight satellites [14, 15] (**Figures 10** and **11**).

#### *3.3.2 Cyclone Global Navigation Satellite System (CYGNSS)*

The Cyclone Global Navigation Satellite System (CYGNSS) is a space-based system developed by the University of Michigan and Southwest Research Institute with the aim of improving hurricane forecasting by better understanding the interactions between the sea and the air near the core of a storm. CYGNSS estimates the wind speed from its radar measurements [15–17]. Winds are measured continuously over the ocean in all weather conditions, although the mission objectives are focused on measurements made in and near the inner core of tropical cyclones Each CYGNSS satellite (eight in total) carries a Delay Doppler Mapping Instrument (DDMI), consisting of:


The instrument receives GPS signals scattered by the ocean surface for the purposes of bi-static scatterometry. The CYGNSS mission was launched on December 15, 2016, at 13:37:21 UTC from a single Pegasus XL air-launched rocket at 35° inclination and 520-km altitude orbit. The eight CYGNSS microsatellites include a Delay Doppler Mapping Instrument consisting of a multichannel GPS receiver, low gain zenith antennas and high gain nadir antenna.

**137**

**Figure 12.**

**Figure 11.**

**Figure 10.**

*A Survey on Small Satellite Technologies and Space Missions for Geodetic Applications*

*(Left) TechDemoSat-1 (TDS-1) prior to launch (Centre) SGR-ReSI SGR-ReSI, part of sea-state payload on* 

Attitude is three-axis stabilized with 2.1° (3σ) knowledge and 2.8° (3σ) control using horizon sensors, a magnetometer, pitch momentum wheel, and torque rods. Satellite mass and power are estimated to be ~25 kg and ~38 Watts. The satellites were built by SwRI and the payload by SSTL USA, based on SSTL's

*(Left) CYGNSS microsatellite platform built by SwRI (Right) delay Doppler mapping instrument (DDMI).*

*Sequence of delay Doppler measurements (DDMs) over a sea/ice boundary near Iceland, march 2015. The* 

*white arrow indicates the boundary as detected by canny edge detection routine [14].*

TDS-1 GPS payload [14, 16] (**Figure 12**).

*DOI: http://dx.doi.org/10.5772/intechopen.92625*

*TDS-1 (Right) TDS-1 nadir GNSS antenna [14].*

*A Survey on Small Satellite Technologies and Space Missions for Geodetic Applications DOI: http://dx.doi.org/10.5772/intechopen.92625*

#### **Figure 10.**

*Satellites Missions and Technologies for Geosciences*

satellites [14, 15] (**Figures 10** and **11**).

• a Delay Mapping Receiver (DMR)

• two nadir-pointing antennas

• one zenith-pointing antenna

*3.3.2 Cyclone Global Navigation Satellite System (CYGNSS)*

The Cyclone Global Navigation Satellite System (CYGNSS) is a space-based system developed by the University of Michigan and Southwest Research Institute with the aim of improving hurricane forecasting by better understanding the interactions between the sea and the air near the core of a storm. CYGNSS estimates the wind speed from its radar measurements [15–17]. Winds are measured continuously over the ocean in all weather conditions, although the mission objectives are focused on measurements made in and near the inner core of tropical cyclones Each CYGNSS satellite (eight in

The instrument receives GPS signals scattered by the ocean surface for the purposes of bi-static scatterometry. The CYGNSS mission was launched on December 15, 2016, at 13:37:21 UTC from a single Pegasus XL air-launched rocket at 35° inclination and 520-km altitude orbit. The eight CYGNSS microsatellites include a Delay Doppler Mapping Instrument consisting of a multichannel GPS receiver, low gain zenith antennas and high gain nadir antenna.

total) carries a Delay Doppler Mapping Instrument (DDMI), consisting of:

GNSS-Reflectometry is a new technique that shows promise for many Earth observation applications including remote sensing of oceans, land, and ice. High grade GNSS payload has been developed in the last few years, that are low in size and power, and suitable for use on small satellites. One such GNSS payload is the SGR-ReSI GNSS Reflectometry Instrument flown on the TechDemoSat-1 microsatellite mission, launched in July 2014. The instrument has been operational since its commissioning in September 2014 and has been collecting delay Doppler maps routinely over many different surfaces. Preliminary work has been undertaken to develop and validate wind speed inversion algorithms against Advanced Scatterometer (ASCAT) wind measurements with promising results [14]. One of the first ever GPS Reflectometry experiments was flown again by Surrey Satellite Technology Limited on the UK-DMC microsatellite mission, launched in 2003, which proved the feasibility of using GNSS reflections for measuring the sea state and other geophysical observables through a partnership between SSTL and National Oceanography Centre (NOC) [14]. Preliminary work using UK-DMC GPS data focused on inverting the measurements into Level 2 products, specifically wind speed and mean-squared slope over the ocean, with promising results. Reflections recovered over the land surface showed a strong geophysical imprint, suggesting potential for hydrological and vegetation related retrieval. Subsequently, a new instrument was developed called the Space GNSS Receiver Remote Sensing Instrument (SGR-ReSI) to gather more space-borne reflectometry data and demonstrate the potential for a sea-state service. In parallel, a US mission called CYGNSS was selected by NASA that plans to measure hurricanes with reflected GNSS signals collected using an updated revision of the SGR-ReSI, (also referred to as delay Doppler mapping Instrument) as payload on each of the eight

*3.3.1 GNSS reflectometry*

**136**

*(Left) TechDemoSat-1 (TDS-1) prior to launch (Centre) SGR-ReSI SGR-ReSI, part of sea-state payload on TDS-1 (Right) TDS-1 nadir GNSS antenna [14].*

#### **Figure 11.**

*Sequence of delay Doppler measurements (DDMs) over a sea/ice boundary near Iceland, march 2015. The white arrow indicates the boundary as detected by canny edge detection routine [14].*

Attitude is three-axis stabilized with 2.1° (3σ) knowledge and 2.8° (3σ) control using horizon sensors, a magnetometer, pitch momentum wheel, and torque rods. Satellite mass and power are estimated to be ~25 kg and ~38 Watts. The satellites were built by SwRI and the payload by SSTL USA, based on SSTL's TDS-1 GPS payload [14, 16] (**Figure 12**).

#### *3.3.3 Formosa Satellite-7/Constellation Observing System for Meteorology Ionosphere and Climate (FORMOSAT-7/COSMIC-2)*

The Formosa Satellite-7/Constellation Observing System for Meteorology Ionosphere and Climate (FORMOSAT-7/COSMIC-2, hereafter C2), is a recently launched equatorial constellation of six satellites carrying advanced radio occultation receivers, which exhibit high signal-to-noise ratio, precision, and accuracy, and the ability to provide high vertical resolution profiles of bending angles and refractivity, which contain information on temperature and water vapor in the challenging tropical atmosphere. The mission is an international collaboration between Taiwan (NSPO) and the United States (NOAA) that will use a constellation of 12 remote sensing microsatellites (planned) to collect atmospheric data for weather prediction and for ionosphere, climate and gravity research. Budget constraints have meant that the constellation will most likely remain to the current number of 6 currently in orbit [17]. The first six satellites, built by SSTL (UK) were launched on June 25 via the SpaceX Falcon 9 launcher to an initial circular parking orbit of 720 km. Eventually, they were positioned in a low inclination orbit at a nominal altitude of ~520–550 km with an inclination of 24° (using their propulsion system). Through constellation deployment, they are placed into 6 orbital planes with 60° separation. The satellites, built by SSTL in the UK have a mass of 300 kg and are based on SSTL's 150 kg microsatellite platform, with dimensions 100 × 125 × 125 cm3 , uses S band (2 Mbps download), 2 GB data storage, utilize nine downlink stations and have a hydrazine monopropellant propulsion system to lower their initial 725 km orbit to a 550 km final operational orbit.

After an initial calibration/validation phase, over 100,000 soundings of bending angles and refractivity that passed quality control in October 2019 and are being compared with independent data, including radiosondes, model forecasts, and analyses. The comparisons show that C2 data meet expectations of high accuracy, precision, and capability to detect super refraction. When fully operational, the C2 satellites are expected to produce ~5000 soundings per day, providing freely available observations that will enable improved forecasts of weather, including tropical cyclones, and weather, space weather, and climate research (**Figure 13**).

#### **Figure 13.**

*(Left) COSMIC-2 on Falcon 9 Heavy (Right) 110 neutral atmospheric occultations within 3 h of receiving the first level 0 data [16].*

**139**

missions is presented.

**4. Geodetic smallsat mission concepts**

*A Survey on Small Satellite Technologies and Space Missions for Geodetic Applications*

the Gravity field and steady-state Ocean Circulation Explorer (GOCE) [23].

As mentioned, the miniaturization of small satellites and instrumentation and the overall low cost of small satellite missions, makes them ideal vehicles to expand drag free mission principles. Section 4 details multiple cubesat based drag free mission concepts which are in the design phase and which will fly into space in the next few years. In the following section a brief overview of the GRACE and GOCE

The availability of reusable launch vehicles such as the SpaceX Falcon 9 and 9 Heavy and the further miniaturization of small satellites and instruments to the cubesat form factor (1–3 U) and mass (<5 kg) has led to the proposal of multiple constellation based geodetic missions which are currently being investigated. The section below provides a brief overview of some of these mission concepts [19–27]. CNES has performed the preliminary design studies of a mission for a future nano-

satellite constellation of GNSS-RO receivers for a targeted number of occultations:

Drag-free space systems [11–19] provide autonomous precision orbit determination, more accurately map the static and time varying components of Earth's mass distribution, aid in our understanding of the fundamental force of gravity, and ultimately open up a new window to our universe through the detection and observation of gravitational waves. At the heart of this technology is a gravitational reference sensor, which (a) contains and shields a free-floating test mass from all non-gravitational forces, and (b) precisely measures the position of the test mass inside the sensor. A feedback control system commands thrusters to fly the "tender" spacecraft with respect to the test mass [16]. Thus, both test mass and spacecraft follow a pure geodesic in spacetime. By tracking the position of a low Earth orbiting drag-free satellite we can directly determine the detailed shape of geodesics and through analysis, the higher order harmonics of the Earth's geopotential. In addition to geodesic information, the commanded thrust, test mass position and GPS tracking data can be combined to produce three dimensional maps of atmospheric winds and density. With multiple drag-free spacecraft, one can perform a more accurate differential measurement between two geodesics, for example with laser interferometry, in order to improve measurements made by NASA's twin GRACE satellites [12, 18]. The range of applications for drag-free technology is broad. A summary is provided in **Table 3** combined with other geodesic mission types [20]. The listed applications are separated into four distinct categories: navigation, Earth science, fundamental physics, and astrophysics. Two key performance metrics for each application are also shown. The first metric, called drag-free performance, is the residual acceleration of the test mass. For an ideal drag-free satellite, the residual acceleration is zero, but in practice small, residual forces act on the test mass, perturbing its trajectory with respect to a pure geodesic. The primary goal of drag-free satellite design is to minimize these residual forces. The second metric, called metrology, is either the measurement of the absolute position of a drag-free test mass (e.g. via GPS) or the differential measurement of the distance between two drag-free test masses. Space missions which implemented this concepts were the drag-free satellites: NASA's Gravity Probe B (GP-B), which tested two predictions of general relativity with ultraprecise drag-free gyroscopes in low Earth orbit [21–23], and ESA's geodesy mission,

*DOI: http://dx.doi.org/10.5772/intechopen.92625*

**3.4 Drag free space missions**

*A Survey on Small Satellite Technologies and Space Missions for Geodetic Applications DOI: http://dx.doi.org/10.5772/intechopen.92625*

#### **3.4 Drag free space missions**

*Satellites Missions and Technologies for Geosciences*

platform, with dimensions 100 × 125 × 125 cm3

operational orbit.

research (**Figure 13**).

*3.3.3 Formosa Satellite-7/Constellation Observing System for Meteorology* 

The Formosa Satellite-7/Constellation Observing System for Meteorology Ionosphere and Climate (FORMOSAT-7/COSMIC-2, hereafter C2), is a recently launched equatorial constellation of six satellites carrying advanced radio occultation receivers, which exhibit high signal-to-noise ratio, precision, and accuracy, and the ability to provide high vertical resolution profiles of bending angles and refractivity, which contain information on temperature and water vapor in the challenging tropical atmosphere. The mission is an international collaboration between Taiwan (NSPO) and the United States (NOAA) that will use a constellation of 12 remote sensing microsatellites (planned) to collect atmospheric data for weather prediction and for ionosphere, climate and gravity research. Budget constraints have meant that the constellation will most likely remain to the current number of 6 currently in orbit [17]. The first six satellites, built by SSTL (UK) were launched on June 25 via the SpaceX Falcon 9 launcher to an initial circular parking orbit of 720 km. Eventually, they were positioned in a low inclination orbit at a nominal altitude of ~520–550 km with an inclination of 24° (using their propulsion system). Through constellation deployment, they are placed into 6 orbital planes with 60° separation. The satellites, built by SSTL in the UK have a mass of 300 kg and are based on SSTL's 150 kg microsatellite

2 GB data storage, utilize nine downlink stations and have a hydrazine monopropellant propulsion system to lower their initial 725 km orbit to a 550 km final

After an initial calibration/validation phase, over 100,000 soundings of bending angles and refractivity that passed quality control in October 2019 and are being compared with independent data, including radiosondes, model forecasts, and analyses. The comparisons show that C2 data meet expectations of high accuracy, precision, and capability to detect super refraction. When fully operational, the C2 satellites are expected to produce ~5000 soundings per day, providing freely available observations that will enable improved forecasts of weather, including tropical cyclones, and weather, space weather, and climate

*(Left) COSMIC-2 on Falcon 9 Heavy (Right) 110 neutral atmospheric occultations within 3 h of receiving the* 

, uses S band (2 Mbps download),

*Ionosphere and Climate (FORMOSAT-7/COSMIC-2)*

**138**

**Figure 13.**

*first level 0 data [16].*

Drag-free space systems [11–19] provide autonomous precision orbit determination, more accurately map the static and time varying components of Earth's mass distribution, aid in our understanding of the fundamental force of gravity, and ultimately open up a new window to our universe through the detection and observation of gravitational waves. At the heart of this technology is a gravitational reference sensor, which (a) contains and shields a free-floating test mass from all non-gravitational forces, and (b) precisely measures the position of the test mass inside the sensor. A feedback control system commands thrusters to fly the "tender" spacecraft with respect to the test mass [16]. Thus, both test mass and spacecraft follow a pure geodesic in spacetime. By tracking the position of a low Earth orbiting drag-free satellite we can directly determine the detailed shape of geodesics and through analysis, the higher order harmonics of the Earth's geopotential. In addition to geodesic information, the commanded thrust, test mass position and GPS tracking data can be combined to produce three dimensional maps of atmospheric winds and density. With multiple drag-free spacecraft, one can perform a more accurate differential measurement between two geodesics, for example with laser interferometry, in order to improve measurements made by NASA's twin GRACE satellites [12, 18].

The range of applications for drag-free technology is broad. A summary is provided in **Table 3** combined with other geodesic mission types [20]. The listed applications are separated into four distinct categories: navigation, Earth science, fundamental physics, and astrophysics. Two key performance metrics for each application are also shown. The first metric, called drag-free performance, is the residual acceleration of the test mass. For an ideal drag-free satellite, the residual acceleration is zero, but in practice small, residual forces act on the test mass, perturbing its trajectory with respect to a pure geodesic. The primary goal of drag-free satellite design is to minimize these residual forces. The second metric, called metrology, is either the measurement of the absolute position of a drag-free test mass (e.g. via GPS) or the differential measurement of the distance between two drag-free test masses. Space missions which implemented this concepts were the drag-free satellites: NASA's Gravity Probe B (GP-B), which tested two predictions of general relativity with ultraprecise drag-free gyroscopes in low Earth orbit [21–23], and ESA's geodesy mission, the Gravity field and steady-state Ocean Circulation Explorer (GOCE) [23].

As mentioned, the miniaturization of small satellites and instrumentation and the overall low cost of small satellite missions, makes them ideal vehicles to expand drag free mission principles. Section 4 details multiple cubesat based drag free mission concepts which are in the design phase and which will fly into space in the next few years. In the following section a brief overview of the GRACE and GOCE missions is presented.

#### **4. Geodetic smallsat mission concepts**

The availability of reusable launch vehicles such as the SpaceX Falcon 9 and 9 Heavy and the further miniaturization of small satellites and instruments to the cubesat form factor (1–3 U) and mass (<5 kg) has led to the proposal of multiple constellation based geodetic missions which are currently being investigated. The section below provides a brief overview of some of these mission concepts [19–27].

CNES has performed the preliminary design studies of a mission for a future nanosatellite constellation of GNSS-RO receivers for a targeted number of occultations:


MicroGEM (Microsatellites for GNSS Earth Monitoring) was a phase A study which proposed the use of satellites with a mass of 100 kg for monitoring of the Earth. The study explored how miniaturization of microsatellites and instrumentational can enable low cost geodetic missions. Using GPS/Galileo receivers and the GFZ-satellite missions CHAMP (CHAllenging Minisatellite Payload) and GRACE (Gravity Recovery and Climate Experiment) philosophy a small constellation is proposed. MicroGEM studied how to link the CHAMP and GRACE missions with cubesat/microsatellite technology and proposed for the first time to use the signals from the future Galileo-satellites for the GNSS-supported atmospheric and ionospheric remote sensing on a global scale. The study analyzed the significant improvements in this method. It also proposed to use GNSS-signals for the remote sensing of ocean and ice surface will be employed for the first time. The particular technological challenge of MicroGEM lies in the fact that this small satellite mission could serve as a predecessor for future multi-satellite systems with scientific GNSS-receivers as satellite payload. With such constellations the number of measurements can be considerably increased, and an improved global coverage can be achieved [24].

The proposed PRETTY (Passive Reflectometry and Dosimetry) mission included a demonstrator payload for passive reflectometry and scatterometry focusing on very low incidence angles whereby the direct and reflected signal will be received via the same antenna. The correlation of both signals will be done by a specific FPGA based hardware implementation. The demonstration of a passive reflectometer without the use of local code replica implicitly showed that also signals of unknown data modulation can be exploited for such a purpose. The PRETTY mission was proposed by an Austrian consortium with RUAG GmbH as prime contractor, relying on the results from a previous CubeSat mission (OPS-SAT) conducted by TU Graz under ESA contract [25].

GEOCON was another cubesat type study which is investigating the development of a new measurement concept using one or more space-based reference points (satellites) to significantly reduce the errors in the site ties between co-located geodetic ground stations. The proposed concept uses a novel idea of upconverting the Global Navigation Satellite System (GNSS) signal received at the satellite and transponding it to a Very Long Baseline Interferometry (VLBI) antenna ground station. This approach does not require the satellite to be in view of more than one VLBI station at a time, allowing the use of Low Earth Orbits. This is advantageous since it opens up the possibility of using inexpensive CubeSats or other small satellites, making it feasible to implement a cost-effective constellation of such satellites (GEOCON) to provide better global coverage and further improve the accuracy of the site ties for the Global Geodetic Observing System—GGOS, stations' network.

**141**

**5. Conclusion**

*A Survey on Small Satellite Technologies and Space Missions for Geodetic Applications*

A Drag-Free CubeSat mission has been proposed recently, to demonstrate the feasibility of a Gravitational Reference Sensor (GRS) with an optical readout for a 3 units (3 U) spacecraft [27, 28]. A purely drag-free object is defined by the absence of all external forces other than gravity, which are shielded by the spacecraft. In a real case, the spherical test mass (TM) will still be affected by disturbances. Several of them are passively reduced by the design of the TM housing. This system is a thick-walled aluminum box that holds the shadow sensors and shields the TM. The housing has an effect on the mechanical, thermal and magnetic environment around the TM. All of them have been analyzed. The mechanical vibrations have to fit the launch environment and the modes have to be outside of the measurement range (0.0001–1 Hz). The housing, together with the TM, the sensors and the UV LEDs for charging control, constitutes the GRS, which would then fit into a 1 U. The other 2Us are occupied by the caging mechanism that constraints the TM during launch, the thrusters, the Attitude Determination and Control System (ADACS) and the electronics. The Drag-Free CubeSat will be the result of the combined efforts of Stanford, University of Florida, KACST and NASA and will be the first drag-free mission with an optical readout and the first GRS designed within the limits of a 3 U small satellite [27]. The 1 U GRS consists of a 25 mm diameter spherical test mass housed inside a 50 mm cubic cavity. The sphere's position is sensed with a LED-based differential optical shadow sensor, its electric charge is controlled by photoemission using UV LEDs, and the spacecraft position is maintained with respect to the sphere using a cold gas micro-propulsion system. The Drag-free CubeSat is a 3-unit (3 U) CubeSat, measuring 34 cm × 10 cm × 10 cm and weighing 4 kg at launch. The drag-free control system uses the satellite position measurement provided by the shadow sensor and a small cold gas thruster in the aft of the satellite to compensate for atmospheric drag and keep the spacecraft centred with respect to the test mass. A commercially available Attitude Determination and Control System (ADACS) will maintain the satellite's attitude pointed in the direction of the drag force, as well as control the satellite's roll angle [28]. The target performance of the Drag-free CubeSat is roughly 10 times better than the GRACE accelerometers and comparable to the drag-free performance of GOCE. The performance is limited primarily by the minimum impulse bit and thrust noise of available CubeSat scale thrusters (**Figure 14**).

*CAD model of the Drag-free CubeSat (Right) drawing of the 1 U GRS payload [28].*

Geodetic missions have benefited from small satellite technology, with space missions such as GOCE, CHAMP, CRACE, GRACE-FO. Advances in GPS technology, sensors (accelerometers), microelectronics and the wide use of cubesat (<5 kg)

*DOI: http://dx.doi.org/10.5772/intechopen.92625*

**Figure 14.**

*A Survey on Small Satellite Technologies and Space Missions for Geodetic Applications DOI: http://dx.doi.org/10.5772/intechopen.92625*

**Figure 14.** *CAD model of the Drag-free CubeSat (Right) drawing of the 1 U GRS payload [28].*

A Drag-Free CubeSat mission has been proposed recently, to demonstrate the feasibility of a Gravitational Reference Sensor (GRS) with an optical readout for a 3 units (3 U) spacecraft [27, 28]. A purely drag-free object is defined by the absence of all external forces other than gravity, which are shielded by the spacecraft. In a real case, the spherical test mass (TM) will still be affected by disturbances. Several of them are passively reduced by the design of the TM housing. This system is a thick-walled aluminum box that holds the shadow sensors and shields the TM. The housing has an effect on the mechanical, thermal and magnetic environment around the TM. All of them have been analyzed. The mechanical vibrations have to fit the launch environment and the modes have to be outside of the measurement range (0.0001–1 Hz). The housing, together with the TM, the sensors and the UV LEDs for charging control, constitutes the GRS, which would then fit into a 1 U. The other 2Us are occupied by the caging mechanism that constraints the TM during launch, the thrusters, the Attitude Determination and Control System (ADACS) and the electronics. The Drag-Free CubeSat will be the result of the combined efforts of Stanford, University of Florida, KACST and NASA and will be the first drag-free mission with an optical readout and the first GRS designed within the limits of a 3 U small satellite [27].

The 1 U GRS consists of a 25 mm diameter spherical test mass housed inside a 50 mm cubic cavity. The sphere's position is sensed with a LED-based differential optical shadow sensor, its electric charge is controlled by photoemission using UV LEDs, and the spacecraft position is maintained with respect to the sphere using a cold gas micro-propulsion system. The Drag-free CubeSat is a 3-unit (3 U) CubeSat, measuring 34 cm × 10 cm × 10 cm and weighing 4 kg at launch. The drag-free control system uses the satellite position measurement provided by the shadow sensor and a small cold gas thruster in the aft of the satellite to compensate for atmospheric drag and keep the spacecraft centred with respect to the test mass. A commercially available Attitude Determination and Control System (ADACS) will maintain the satellite's attitude pointed in the direction of the drag force, as well as control the satellite's roll angle [28]. The target performance of the Drag-free CubeSat is roughly 10 times better than the GRACE accelerometers and comparable to the drag-free performance of GOCE. The performance is limited primarily by the minimum impulse bit and thrust noise of available CubeSat scale thrusters (**Figure 14**).

#### **5. Conclusion**

Geodetic missions have benefited from small satellite technology, with space missions such as GOCE, CHAMP, CRACE, GRACE-FO. Advances in GPS technology, sensors (accelerometers), microelectronics and the wide use of cubesat (<5 kg)

*Satellites Missions and Technologies for Geosciences*

remain a low-cost system

• 2 polar ground stations

• 10.000 per day main identified technical specifications to meet the end user

• main planned option for the constellation: 8 LEO satellites, altitude of 600 km

• receiver bi-frequencies (E1 and L5) and bi-GNSS constellation (GPS + Galileo)

MicroGEM (Microsatellites for GNSS Earth Monitoring) was a phase A study which proposed the use of satellites with a mass of 100 kg for monitoring of the Earth. The study explored how miniaturization of microsatellites and instrumentational can enable low cost geodetic missions. Using GPS/Galileo receivers and the GFZ-satellite missions CHAMP (CHAllenging Minisatellite Payload) and GRACE (Gravity Recovery and Climate Experiment) philosophy a small constellation is proposed. MicroGEM studied how to link the CHAMP and GRACE missions with cubesat/microsatellite technology and proposed for the first time to use the signals from the future Galileo-satellites for the GNSS-supported atmospheric and ionospheric remote sensing on a global scale. The study analyzed the significant improvements in this method. It also proposed to use GNSS-signals for the remote sensing of ocean and ice surface will be employed for the first time. The particular technological challenge of MicroGEM lies in the fact that this small satellite mission could serve as a predecessor for future multi-satellite systems with scientific GNSS-receivers as satellite payload. With such constellations the number of measurements can be considerably increased, and an improved global coverage can be achieved [24]. The proposed PRETTY (Passive Reflectometry and Dosimetry) mission included a demonstrator payload for passive reflectometry and scatterometry focusing on very low incidence angles whereby the direct and reflected signal will be received via the same antenna. The correlation of both signals will be done by a specific FPGA based hardware implementation. The demonstration of a passive reflectometer without the use of local code replica implicitly showed that also signals of unknown data modulation can be exploited for such a purpose. The PRETTY mission was proposed by an Austrian consortium with RUAG GmbH as prime contractor, relying on the results from a previous CubeSat mission (OPS-

GEOCON was another cubesat type study which is investigating the development of a new measurement concept using one or more space-based reference points (satellites) to significantly reduce the errors in the site ties between co-located geodetic ground stations. The proposed concept uses a novel idea of upconverting the Global Navigation Satellite System (GNSS) signal received at the satellite and transponding it to a Very Long Baseline Interferometry (VLBI) antenna ground station. This approach does not require the satellite to be in view of more than one VLBI station at a time, allowing the use of Low Earth Orbits. This is advantageous since it opens up the possibility of using inexpensive CubeSats or other small satellites, making it feasible to implement a cost-effective constellation of such satellites (GEOCON) to provide better global coverage and further improve the accuracy of the site ties for the Global Geodetic Observing

• small size and small mass (<50 kg) with a minimalist instrumentation to

requirements and comply with the low-cost constraint

• array antenna with at least 8 dB gain and 50° coverage

SAT) conducted by TU Graz under ESA contract [25].

System—GGOS, stations' network.

**140**

nanosatellite technology allows for drastic mass and volume reduction of satellite platforms and instruments and thus allowing microsatellite/cubesat type constellations to offer unique measurement capabilities for geodetic applications. New mission concepts using reflectometry, occultation, ionospheric research and drag free payloads are presented focused on cubesat level technology and size factors, which in combination with lowering launch costs and an increase in launch opportunities bring a new setting to conduct unprecedented geodetic missions with higher temporal resolution and higher measurement accuracy compared to what is available at present.

#### **Author details**

Vaios Lappas\* and Vassilis Kostopoulos Applied Mechanics Lab, University of Patras, Rio, Greece

\*Address all correspondence to: vlappas@upatras.gr

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

**143**

*A Survey on Small Satellite Technologies and Space Missions for Geodetic Applications*

relativity with the LARES and LAGEOS satellites. Nuclear Physics B - Proceedings Supplements.

[9] Burmistrov VB, Vasiliev VP, Parkhomenko NN, Shargorodsk VD. REFLECTOR, LARETS and METEOR-3M missions. In: IPIE Presentation at 14th International Workshop on Laser Ranging. San Fernando, Spain; 2004. Available from: https://cddis.nasa.gov/ lw14/docs/presnts/tar3a\_vbp.pdf

[10] CHAMP Mission Website. Available from: https://www.gfz-potsdam.de/en/ section/geomagnetism/infrastructure/

[11] Tapley B. GRACE—Gravity Recovery and Climate Experiment. NASA. 2011. Available from: http://solarsystem.nasa. gov/scitech/display.cfm?ST\_ID=186

2013;**243-244**:180-193

champ/satellite-systems/

[12] Tapley BD, Bettadpur S, Watkins M, Reigber C. The gravity recovery and climate experiment: mission overview and early results. Geophysical Research Letters. 2004;**31**

[13] Webb F, Flechtner F, Landerer F, Morton P, Watkins M, Save H, et al. Gravity recovery and climate experiment follow-on mission. In: Proceedings of the 70th IAC

(International Astronautical Congress); Washington DC, USA; 21-25 October 2019. Paper: IAC-19.B1.1. Available from: https://iafastro.directory/iac/ proceedings/IAC-19/IAC-19/B1/2/ manuscripts/IAC-19,B1,2,4,x54184.pdf

[14] Unwin M. TechDemoSat-1 and the GNSS reflectometry experiment. In: TechDemoSat-1 User Consultation Meeting. Southampton, United Kingdom: National Oceanography Centre; 2015. Available from: http://www.merrbys.co.uk:8080/ CatalogueData/Documents/TDS1%20

SGRReSI%20Experiment.pdf

*DOI: http://dx.doi.org/10.5772/intechopen.92625*

[1] Beutler G. Revolution in Geodesy and Surveying. International Federation of Surveyors. Article of the Month: July 2004. Available from: https://www.fig. net/resources/monthly\_articles/2004/ july\_2004/beutler\_july\_2004.pdf

[2] Potential Applications of Satellite Geodetic Techniques to Geosciences, by United States. National Aeronautics and Space Administration, Ad Hoc Advisory Group. NASA Report SP-158; 1968

[3] Heinkelmann R. VLBI Geodesy: Observations, Analysis and Results, Geodetic Sciences—Observations, Modeling and Applications. Rijeka, Croatia: IntechOpen; 2013. DOI: 10.5772/54446. Available from: https://www.intechopen.com/books/ geodetic-sciences-observations-

modeling-and-applications/vlbi-geodesyobservations-analysis-and-results

Applications. De Gruyter Publishing; 2008. DOI: 10.1515/9783110200089

[6] Website of GeoForschungs Zentrum Potsdam. Available from: https://www. gfz-potsdam.de/en/section/globalgeomonitoring-and-gravity-field/ projects/abgeschlossene-projekte/ geo-research-satellite-gfz-1/

[7] Paolozzi A, Ciufolini I. LARES successfully launched in orbit:

from: http://arxiv.org/ftp/arxiv/ papers/1305/1305.6823.pdf

[8] Ciufolini I, Paolozzi A, König R, Pavlis EC, Ries JC, Matzner R, et al. Fundamental physics and general

Satellite and mission description. Acta Astronautica. 2013;**91**:313-321. Available

[5] Kramer HJ. Observation of the Earth and Its Environment: Survey of Missions and Sensors. Springer-Verlag Berlin Heidelberg: Springer; 2002. ISBN:

978-3-642-56294-5

[4] Seeber G. Satellite Geodesy: Foundations, Methods, and

**References**

*A Survey on Small Satellite Technologies and Space Missions for Geodetic Applications DOI: http://dx.doi.org/10.5772/intechopen.92625*

#### **References**

*Satellites Missions and Technologies for Geosciences*

nanosatellite technology allows for drastic mass and volume reduction of satellite platforms and instruments and thus allowing microsatellite/cubesat type constellations to offer unique measurement capabilities for geodetic applications. New mission concepts using reflectometry, occultation, ionospheric research and drag free payloads are presented focused on cubesat level technology and size factors, which in combination with lowering launch costs and an increase in launch opportunities bring a new setting to conduct unprecedented geodetic missions with higher temporal resolution and higher measurement accuracy compared to what is available at present.

**142**

**Author details**

Vaios Lappas\* and Vassilis Kostopoulos

provided the original work is properly cited.

Applied Mechanics Lab, University of Patras, Rio, Greece

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

\*Address all correspondence to: vlappas@upatras.gr

[1] Beutler G. Revolution in Geodesy and Surveying. International Federation of Surveyors. Article of the Month: July 2004. Available from: https://www.fig. net/resources/monthly\_articles/2004/ july\_2004/beutler\_july\_2004.pdf

[2] Potential Applications of Satellite Geodetic Techniques to Geosciences, by United States. National Aeronautics and Space Administration, Ad Hoc Advisory Group. NASA Report SP-158; 1968

[3] Heinkelmann R. VLBI Geodesy: Observations, Analysis and Results, Geodetic Sciences—Observations, Modeling and Applications. Rijeka, Croatia: IntechOpen; 2013. DOI: 10.5772/54446. Available from: https://www.intechopen.com/books/ geodetic-sciences-observationsmodeling-and-applications/vlbi-geodesyobservations-analysis-and-results

[4] Seeber G. Satellite Geodesy: Foundations, Methods, and Applications. De Gruyter Publishing; 2008. DOI: 10.1515/9783110200089

[5] Kramer HJ. Observation of the Earth and Its Environment: Survey of Missions and Sensors. Springer-Verlag Berlin Heidelberg: Springer; 2002. ISBN: 978-3-642-56294-5

[6] Website of GeoForschungs Zentrum Potsdam. Available from: https://www. gfz-potsdam.de/en/section/globalgeomonitoring-and-gravity-field/ projects/abgeschlossene-projekte/ geo-research-satellite-gfz-1/

[7] Paolozzi A, Ciufolini I. LARES successfully launched in orbit: Satellite and mission description. Acta Astronautica. 2013;**91**:313-321. Available from: http://arxiv.org/ftp/arxiv/ papers/1305/1305.6823.pdf

[8] Ciufolini I, Paolozzi A, König R, Pavlis EC, Ries JC, Matzner R, et al. Fundamental physics and general

relativity with the LARES and LAGEOS satellites. Nuclear Physics B - Proceedings Supplements. 2013;**243-244**:180-193

[9] Burmistrov VB, Vasiliev VP, Parkhomenko NN, Shargorodsk VD. REFLECTOR, LARETS and METEOR-3M missions. In: IPIE Presentation at 14th International Workshop on Laser Ranging. San Fernando, Spain; 2004. Available from: https://cddis.nasa.gov/ lw14/docs/presnts/tar3a\_vbp.pdf

[10] CHAMP Mission Website. Available from: https://www.gfz-potsdam.de/en/ section/geomagnetism/infrastructure/ champ/satellite-systems/

[11] Tapley B. GRACE—Gravity Recovery and Climate Experiment. NASA. 2011. Available from: http://solarsystem.nasa. gov/scitech/display.cfm?ST\_ID=186

[12] Tapley BD, Bettadpur S, Watkins M, Reigber C. The gravity recovery and climate experiment: mission overview and early results. Geophysical Research Letters. 2004;**31**

[13] Webb F, Flechtner F, Landerer F, Morton P, Watkins M, Save H, et al. Gravity recovery and climate experiment follow-on mission. In: Proceedings of the 70th IAC (International Astronautical Congress); Washington DC, USA; 21-25 October 2019. Paper: IAC-19.B1.1. Available from: https://iafastro.directory/iac/ proceedings/IAC-19/IAC-19/B1/2/ manuscripts/IAC-19,B1,2,4,x54184.pdf

[14] Unwin M. TechDemoSat-1 and the GNSS reflectometry experiment. In: TechDemoSat-1 User Consultation Meeting. Southampton, United Kingdom: National Oceanography Centre; 2015. Available from: http://www.merrbys.co.uk:8080/ CatalogueData/Documents/TDS1%20 SGRReSI%20Experiment.pdf

[15] Rose R, Wells W, Rose D, Ruf C, Ridley A, Nave K. Nanosat technology and managed risk: An update of the CYGNSS microsatellite constellation mission development. In: Proceedings of the AIAA/USU Conference on Small Satellites. Logan, Utah, USA; 2-7 August 2014. Paper: SSC14-VI-4. Available from: http:// digitalcommons.usu.edu/cgi/viewcontent. cgi?article=3103&context=smallsat

[16] Ruf C. Two Year Anniversary of CYGNSS on Orbit. NASA Earth Observatory. 2018. Available from: https://earthobservatory.nasa.gov/ blogs/fromthefield/2018/12/15/twoyear-anniversary-of-cygnss-on-orbit/

[17] Ruf C, Asharaf S,

Balasubramaniam R, Gleason S, Lang T, McKague D, et al. In-orbit performance of the constellation of CYGNSS hurricane satellites. Bulletin of the American Meteorological Society. 2019. DOI: 10.1175/BAMS-D-18-0337.1

[18] Barney RD et al. DRAFT science instruments, observatories, and sensor systems roadmap. In: Technology Area 08; NASA; 2008

[19] Touboul P, Rodrigues M, Metris G, Tatry B. MICROSCOPE, testing the equivalence principle in space. Comptes Rendus de l'Academie des Sciences, Series IV Physics. 2001;**2**(9)

[20] Conklin J, Nguyen A. Drag-free control and drag force recovery of small satellites. In: 31st AIAA Utah Small Satellite Conference. Utah; 2017

[21] Danzmann K, Rudiger A. LISA technology—Concept, status, prospects. Classical and Quantum Gravity. 2003;**20**

[22] Everitt CWF et al. Gravity probe B: Final results of a space experiment to test general relativity. Physical Review Letters. 2011;**106**(22)

[23] Canuto E. Drag-free and attitude control for the GOCE satellite. Automatica. 2008;**44**(7)

[24] Briess K, Kornemann G, Wickert J, MicroGEM: Microsatellites for GNSS earth monitoring. Abschlussbericht Phase 0/A; 2009. p. 244. Available from: https://www.gnss.tu-berlin.de/menue/ forschung/aktuelle\_projekte/gnss\_ fernerkundung\_mit\_kleinsatelliten/

[25] Høeg P, Fragner H, Dielacher A, Zangerl F, Koudelka O, Høeg P, et al. PRETTY: Grazing altimetry measurements based on the interferometric method. In: Proceedings of the 5th Workshop on Advanced RF Sensors and Remote Sensing Instruments (ARSI'17); European Space Agency, GPS Reflectometry; 2017. Available from: https://backend.orbit. dtu.dk/ws/portalfiles/portal/134709739/ ARSI17\_Fragner\_PRETTY\_2017.pdf

[26] Pavlis EC, Merkowitz SM, Beaudoin CJ, Kuzmicz-Cieslak M, Rowlands DD, Lemoine FG. GEOCON: Geodetic system ties using a CubeSat constellation. Geophysical Research. 2019;**21**:EGU2019-6158-1. EGU General Assembly 2019. Available from: https:// meetingorganizer.copernicus.org/ EGU2019/EGU2019-6158-1.pdf

[27] Conklin J, Nguyen A. Drag-free control and drag force recovery of small satellites. In: 31st AIAA Utah Small Satellite Conference. Utah; 2017. Available from: https://digitalcommons. usu.edu/cgi/viewcontent.cgi?article=36 91&context=smallsat

[28] Zanoni C, Alfauwaz A, Aljadaan A, Althubiti S, Balakrishnan K, Buchman S, et al. The design of a dragfree CubeSat and the housing for its gravitational reference sensor. In: 2nd IAA Conference on University Satellites Missions and CubeSat Workshop. 2016. IAA-CU-13-12-01. Available from: https://www.researchgate.net/ publication/303331084\_The\_Design\_ of\_a\_Drag-Free\_CubeSat\_and\_the\_ Housing\_for\_its\_Gravitational\_ Reference\_Sensor

**145**

**Chapter 9**

Missions

*Adriano Camps*

formation flying, synthetic apertures…

planetary exploration, enabling technologies

**1.1 From the sputnik to the CubeSats**

mission ended after 3 weeks when batteries died.

**1. Introduction**

**Abstract**

Nanosatellites and Applications

In the past two decades, a silent revolution has taken place in the space domain, leading to what today is known as "New Space." We have passed from a selected group of countries, space agencies, and big industries building, launching, and operating satellites and other spacecrafts, of a scenario in which many universities and research institutes can do it. The key of this was the definition of the "CubeSat" standard, back to 1999. In 2013, it all took off on the commercial Earth Observation sector with the first launches from two companies that are now running 100+ CubeSat constellations for optical imaging or weather prediction, with very low revisit times. Today, the same revolution is taking place in the fields of Telecommunications, and Astronomical Scientific missions. In this chapter, the evolution of the space sector is briefly revised until the arrival of the CubeSats. Then, the CubeSat intrinsic limitations are discussed as they are key to understand the development and current situation of the CubeSat sector. NASA and ESA strategies are also presented. The chapter concludes with a summary of the technology roadmap to enable the next generation of CubeSat-based missions, including satellite constellations or federations,

**Keywords:** satellites, CubeSats, mission, earth observation, astronomy,

At the beginning of the space age, all satellites were "small." Sputnik 1 was the first artificial Earth satellite (**Figure 1a**) [1]. It was launched by the Soviet Union from Baikonur Cosmodrome on October 4, 1957, into an elliptical low Earth orbit (LEO) with an inclination of 65°. Sputnik 1 was a 58-cm-diameter metal sphere, weighing approximately 84 kg, with four radio antennas transmitting at 20.005 and 40.002 MHz. Tracking and studying Sputnik 1 signals from Earth provided valuable information on upper atmosphere density, and the propagation of radio signals provided information on the ionosphere. Sputnik did not have solar panels, so the

to Commercial and Scientific

#### **Chapter 9**

*Satellites Missions and Technologies for Geosciences*

[24] Briess K, Kornemann G, Wickert J, MicroGEM: Microsatellites for GNSS earth monitoring. Abschlussbericht Phase 0/A; 2009. p. 244. Available from: https://www.gnss.tu-berlin.de/menue/ forschung/aktuelle\_projekte/gnss\_ fernerkundung\_mit\_kleinsatelliten/

[25] Høeg P, Fragner H, Dielacher A, Zangerl F, Koudelka O, Høeg P, et al. PRETTY: Grazing altimetry measurements based on the

interferometric method. In: Proceedings of the 5th Workshop on Advanced RF Sensors and Remote Sensing

Instruments (ARSI'17); European Space Agency, GPS Reflectometry; 2017. Available from: https://backend.orbit. dtu.dk/ws/portalfiles/portal/134709739/ ARSI17\_Fragner\_PRETTY\_2017.pdf

[26] Pavlis EC, Merkowitz SM, Beaudoin CJ, Kuzmicz-Cieslak M, Rowlands DD, Lemoine FG. GEOCON: Geodetic system ties using a CubeSat constellation. Geophysical Research. 2019;**21**:EGU2019-6158-1. EGU General Assembly 2019. Available from: https:// meetingorganizer.copernicus.org/ EGU2019/EGU2019-6158-1.pdf

[27] Conklin J, Nguyen A. Drag-free control and drag force recovery of small satellites. In: 31st AIAA Utah Small Satellite Conference. Utah; 2017. Available from: https://digitalcommons. usu.edu/cgi/viewcontent.cgi?article=36

[28] Zanoni C, Alfauwaz A, Aljadaan A,

Buchman S, et al. The design of a dragfree CubeSat and the housing for its gravitational reference sensor. In: 2nd IAA Conference on University Satellites Missions and CubeSat Workshop. 2016. IAA-CU-13-12-01. Available from: https://www.researchgate.net/ publication/303331084\_The\_Design\_ of\_a\_Drag-Free\_CubeSat\_and\_the\_ Housing\_for\_its\_Gravitational\_

91&context=smallsat

Reference\_Sensor

Althubiti S, Balakrishnan K,

[15] Rose R, Wells W, Rose D, Ruf C, Ridley A, Nave K. Nanosat technology and managed risk: An update of the CYGNSS microsatellite constellation mission development. In: Proceedings of the AIAA/USU Conference on Small Satellites. Logan, Utah, USA; 2-7 August 2014. Paper: SSC14-VI-4. Available from: http:// digitalcommons.usu.edu/cgi/viewcontent. cgi?article=3103&context=smallsat

[16] Ruf C. Two Year Anniversary of CYGNSS on Orbit. NASA Earth Observatory. 2018. Available from: https://earthobservatory.nasa.gov/ blogs/fromthefield/2018/12/15/twoyear-anniversary-of-cygnss-on-orbit/

Balasubramaniam R, Gleason S, Lang T, McKague D, et al. In-orbit performance

of the constellation of CYGNSS hurricane satellites. Bulletin of the American Meteorological Society. 2019. DOI: 10.1175/BAMS-D-18-0337.1

[18] Barney RD et al. DRAFT science instruments, observatories, and sensor systems roadmap. In: Technology Area

[19] Touboul P, Rodrigues M, Metris G, Tatry B. MICROSCOPE, testing the equivalence principle in space. Comptes Rendus de l'Academie des Sciences,

[20] Conklin J, Nguyen A. Drag-free control and drag force recovery of small satellites. In: 31st AIAA Utah Small Satellite Conference. Utah; 2017

[21] Danzmann K, Rudiger A. LISA technology—Concept, status, prospects. Classical and Quantum Gravity. 2003;**20**

Letters. 2011;**106**(22)

[22] Everitt CWF et al. Gravity probe B: Final results of a space experiment to test general relativity. Physical Review

[23] Canuto E. Drag-free and attitude control for the GOCE satellite. Automatica. 2008;**44**(7)

Series IV Physics. 2001;**2**(9)

[17] Ruf C, Asharaf S,

08; NASA; 2008

**144**

## Nanosatellites and Applications to Commercial and Scientific Missions

*Adriano Camps*

### **Abstract**

In the past two decades, a silent revolution has taken place in the space domain, leading to what today is known as "New Space." We have passed from a selected group of countries, space agencies, and big industries building, launching, and operating satellites and other spacecrafts, of a scenario in which many universities and research institutes can do it. The key of this was the definition of the "CubeSat" standard, back to 1999. In 2013, it all took off on the commercial Earth Observation sector with the first launches from two companies that are now running 100+ CubeSat constellations for optical imaging or weather prediction, with very low revisit times. Today, the same revolution is taking place in the fields of Telecommunications, and Astronomical Scientific missions. In this chapter, the evolution of the space sector is briefly revised until the arrival of the CubeSats. Then, the CubeSat intrinsic limitations are discussed as they are key to understand the development and current situation of the CubeSat sector. NASA and ESA strategies are also presented. The chapter concludes with a summary of the technology roadmap to enable the next generation of CubeSat-based missions, including satellite constellations or federations, formation flying, synthetic apertures…

**Keywords:** satellites, CubeSats, mission, earth observation, astronomy, planetary exploration, enabling technologies

#### **1. Introduction**

#### **1.1 From the sputnik to the CubeSats**

At the beginning of the space age, all satellites were "small." Sputnik 1 was the first artificial Earth satellite (**Figure 1a**) [1]. It was launched by the Soviet Union from Baikonur Cosmodrome on October 4, 1957, into an elliptical low Earth orbit (LEO) with an inclination of 65°. Sputnik 1 was a 58-cm-diameter metal sphere, weighing approximately 84 kg, with four radio antennas transmitting at 20.005 and 40.002 MHz. Tracking and studying Sputnik 1 signals from Earth provided valuable information on upper atmosphere density, and the propagation of radio signals provided information on the ionosphere. Sputnik did not have solar panels, so the mission ended after 3 weeks when batteries died.

Explorer 1 was the first US satellite (**Figure 1b**) [2], and the third one after Sputnik 1 and 2. It was launched from Cape Canaveral, Florida, on January 31, 1958. Explorer 1 was 205 cm tall and 15 cm in diameter, weighing nearly 14 kg. It was the first spacecraft to detect the Van Allen radiation belts. Explorer 1 did not have solar panels either, so after 4 months the mission ended when batteries were exhausted.

Vanguard 1 was the fourth artificial Earth satellite (**Figure 1c**) [3]. It was launched by the USA from Cape Canaveral on March 17, 1958, into a 654 by 3969 km elliptical orbit with an inclination of 34.25°. Vanguard 1 was a 16.5-cm-diameter aluminum sphere, weighing just 1.47 kg, and it was the first satellite with six solar cells powering two beacons at 108 and 108.03 MHz, which were used to measure the total electron content.

During the first two decades of the space age, each satellite had its own design. They were the art pieces of the space craftsmen. Standard spacecraft busses were practically unknown until the end of the 1970s. In the early 1980s, microsatellites emerged and adopted a radically different design approach to reduce costs, focusing on available and existing technologies and using properly qualified commercial off-the-shelf (COTS) components.

For many years, satellite mass increased as illustrated in **Table 1**. However, except for some military, astronomy, and specific communication applications, it seems that the era of massive satellites is over.

The "small satellite mission philosophy" represents a design-to-cost approach, with strict cost and schedule constraints, often combined with a single mission objective in order to reduce complexity. **Figure 2** from [14] summarizes the standardized definition of satellites according to their weight: picosatellites (0.1–1 kg), nanosatellites (1–10 kg), microsatellites (10–100 kg), and mini-satellites or small/ medium satellites (100–1000 kg).

In the field of Earth observation (EO), this has led to smaller target-focused missions which, with reduced spacecraft and launch costs (shared rides), are enabling massive (>100) satellite constellations of nano- and microsatellites with reduced revisit times, unthinkable just a few years ago.

In the field of satellite communications, there are plans as well to deploy massive constellations of LEO satellites to provide worldwide Internet coverage, IoT services, and machine-to-machine (M2M) communications.

It is anticipated that enhanced inter-satellite communication capabilities (LEOground, LEO-LEO, LEO-MEO, and LEO-GEO) will also improve the performance of EO systems [15]. All this is leading to the evolution of the space segment from monolithic to distributed and federated satellite systems [16], aiming at establishing win-win collaborations between satellites to improve their mission performance by using the unused onboard resources.

**147**

*Nanosatellites and Applications to Commercial and Scientific Missions*

*Heaviest spacecrafts (excluding space stations and manned orbiters).*

**Spacecraft Agency application Mass Duration**

Proton [8] USSR/astronomy 17,000 kg 1965–1969 Compton Gamma Ray Obs. [9] US NASA/astronomy 16,329 kg 1991–2000 Lacrosse [10] US NRO/SAR 14,500–16,000 kg 1988–2005 Hubble Space Telescope [11] US NASA/astronomy 11,110 kg 1990–present ENVISAT [12] ESA/Earth observation 8211 kg 2002–2012 Telstar 19 V [13] Canada/communications 7075 kg 2018–present

US NRO/optical imaging 19,600 kg 1976–present

*DOI: http://dx.doi.org/10.5772/intechopen.90039*

KH-11 Kennen (a.k.a. CRYSTAL, EECS, 1010) [7]

**Table 1.**

**Figure 2.**

**1.2 The CubeSat standard**

*Satellite classification [14].*

The so-called CubeSat standard was conceived in 1999 by Profs. Jordi Puig-Suari of California Polytechnic State University (CalPoly) and Bob Twiggs of Stanford University to allow graduate students to conceive, design, implement, test, and operate in space a complete spacecraft in a "reasonable" amount of time (i.e., the duration of their studies). CubeSats are small satellite multiples of 1 U (1 U: 10 cm × 10 cm × 11.35 cm, weighing less than 1.33 kg), including all the basic subsystems as large satellites but using COTS components. The CubeSat "standard" only defines the mechanical external interfaces, i.e., those referring to the orbital deployer. Originally, it was never meant to be a standard, however, because of its simplicity, it soon became a "de facto" standard. As Prof. Twiggs said in an interview to Spaceflight Now in 2014: "*It all started as a university education program satellite. It was kind of funny. I didn't think that people would criticize it as much as they did, but we got a lot of feedback (…). Another thing that was kind of funny we had no interest from NASA or any of the military organizations. It just wasn't anything they were interested in, so it was all funded without any funding from those aerospace organizations*." The first six CubeSats were launched on a Russian Eurockot on June 30th, 2003. Then, after more than a decade in which the concept silently matured in university labs, space agencies got interested and showed that CubeSat-based mission reliability could be improved by proper engineering. In 2013, it all took off on the commercial Earth Observation sector with the first launches from two companies that are now running 100+ CubeSats constellations for optical imaging or weather prediction, with very low revisit times. Today, many of the initial CubeSat limitations (most notably size, available power, and down-link bandwidth) are being overcome, and the same revolution is starting to take place in the fields of telecommunications, and astronomical scientific missions.

**Figure 1.** *Pictures of (a) sputnik 1 [4], (b) explorer 1 [5], and (c) vanguard 1 [6].*

*Nanosatellites and Applications to Commercial and Scientific Missions DOI: http://dx.doi.org/10.5772/intechopen.90039*


#### **Table 1.**

*Satellites Missions and Technologies for Geosciences*

exhausted.

total electron content.

off-the-shelf (COTS) components.

medium satellites (100–1000 kg).

using the unused onboard resources.

seems that the era of massive satellites is over.

revisit times, unthinkable just a few years ago.

services, and machine-to-machine (M2M) communications.

*Pictures of (a) sputnik 1 [4], (b) explorer 1 [5], and (c) vanguard 1 [6].*

Explorer 1 was the first US satellite (**Figure 1b**) [2], and the third one after Sputnik 1 and 2. It was launched from Cape Canaveral, Florida, on January 31, 1958. Explorer 1 was 205 cm tall and 15 cm in diameter, weighing nearly 14 kg. It was the first spacecraft to detect the Van Allen radiation belts. Explorer 1 did not have solar panels either, so after 4 months the mission ended when batteries were

Vanguard 1 was the fourth artificial Earth satellite (**Figure 1c**) [3]. It was launched by the USA from Cape Canaveral on March 17, 1958, into a 654 by 3969 km elliptical orbit with an inclination of 34.25°. Vanguard 1 was a 16.5-cm-diameter aluminum sphere, weighing just 1.47 kg, and it was the first satellite with six solar cells powering two beacons at 108 and 108.03 MHz, which were used to measure the

During the first two decades of the space age, each satellite had its own design. They were the art pieces of the space craftsmen. Standard spacecraft busses were practically unknown until the end of the 1970s. In the early 1980s, microsatellites emerged and adopted a radically different design approach to reduce costs, focusing on available and existing technologies and using properly qualified commercial

For many years, satellite mass increased as illustrated in **Table 1**. However, except for some military, astronomy, and specific communication applications, it

The "small satellite mission philosophy" represents a design-to-cost approach, with strict cost and schedule constraints, often combined with a single mission objective in order to reduce complexity. **Figure 2** from [14] summarizes the standardized definition of satellites according to their weight: picosatellites (0.1–1 kg), nanosatellites (1–10 kg), microsatellites (10–100 kg), and mini-satellites or small/

In the field of Earth observation (EO), this has led to smaller target-focused missions which, with reduced spacecraft and launch costs (shared rides), are enabling massive (>100) satellite constellations of nano- and microsatellites with reduced

In the field of satellite communications, there are plans as well to deploy massive constellations of LEO satellites to provide worldwide Internet coverage, IoT

It is anticipated that enhanced inter-satellite communication capabilities (LEOground, LEO-LEO, LEO-MEO, and LEO-GEO) will also improve the performance of EO systems [15]. All this is leading to the evolution of the space segment from monolithic to distributed and federated satellite systems [16], aiming at establishing win-win collaborations between satellites to improve their mission performance by

**146**

**Figure 1.**

*Heaviest spacecrafts (excluding space stations and manned orbiters).*

**Figure 2.** *Satellite classification [14].*

#### **1.2 The CubeSat standard**

The so-called CubeSat standard was conceived in 1999 by Profs. Jordi Puig-Suari of California Polytechnic State University (CalPoly) and Bob Twiggs of Stanford University to allow graduate students to conceive, design, implement, test, and operate in space a complete spacecraft in a "reasonable" amount of time (i.e., the duration of their studies). CubeSats are small satellite multiples of 1 U (1 U: 10 cm × 10 cm × 11.35 cm, weighing less than 1.33 kg), including all the basic subsystems as large satellites but using COTS components. The CubeSat "standard" only defines the mechanical external interfaces, i.e., those referring to the orbital deployer. Originally, it was never meant to be a standard, however, because of its simplicity, it soon became a "de facto" standard. As Prof. Twiggs said in an interview to Spaceflight Now in 2014: "*It all started as a university education program satellite. It was kind of funny. I didn't think that people would criticize it as much as they did, but we got a lot of feedback (…). Another thing that was kind of funny we had no interest from NASA or any of the military organizations. It just wasn't anything they were interested in, so it was all funded without any funding from those aerospace organizations*." The first six CubeSats were launched on a Russian Eurockot on June 30th, 2003. Then, after more than a decade in which the concept silently matured in university labs, space agencies got interested and showed that CubeSat-based mission reliability could be improved by proper engineering. In 2013, it all took off on the commercial Earth Observation sector with the first launches from two companies that are now running 100+ CubeSats constellations for optical imaging or weather prediction, with very low revisit times. Today, many of the initial CubeSat limitations (most notably size, available power, and down-link bandwidth) are being overcome, and the same revolution is starting to take place in the fields of telecommunications, and astronomical scientific missions.

**Figure 3.** *CubeSat form factors from 1 U to 12 U [20].*

The current CubeSat Design Specification defines the envelopes for 1 U, 1.5 U, 2 U, 3 U and 3 U+, and 6 U form factors (see, e.g., CubeSat Design Specification Rev. 13 or 6 U CubeSat Design Specification in [17], **Figure 3**), and the standardization of 12 U and 16 U is in progress, although some companies have produced standards up to 27 U [18]. On the other side, smaller picosatellites, the so-called PocketQubes, about 1/8 the size of a CubeSat, have also been standardized [19].

Probably, what has had the most significant impact in the popularization of the CubeSat standard has been the capability to separate the interface between the spacecraft and the poly-picosatellite orbital deployer (P-POD) and between the dispenser and the rocket itself. There are two different classes of PODs. The first type is the classical one with four rails in the corners [17], and the second one is with tables [18]. Note however that modern deployers from ISIS and NanoRacks allow larger deployables, wider solar panels, and thinner rails as compared to original P-POD, e.g., increased extruded height up to 9 mm and up to 2 kg per 1 U.

As of June 2019, 64 countries have launched nanosatellites or CubeSats. The total number of nanosatellites launched is 1186, from which 1088 are CubeSats. Most of them (273) have been launched from the International Space Station at ~400 km orbital height with an inclination of 51.6° and the rest at low Earth orbits (LEO) typically at 500 km sun-synchronous orbit (SSO) with an inclination of 97.5° (217 CubeSats) and 580 km height with 97.8° inclination (80 CubeSats). So far, only two (MarCO-1 and MarCO-2) have performed interplanetary missions.

#### **1.3 Current status**

**Figure 4** shows the number of nanosatellites launched per year (a) and organization, either companies, universities, space agencies, etc., or (b) form factor from picosats, 0.25 up to 16 U.

As it can be appreciated, until 2013 most CubeSats were launched by universities and research institutes, and most of them were 1 U or 2 U. However, in 2013 the first 3 U CubeSats from the Planet Labs Inc. [22] and Spire Global Inc. [23] were launched. That was the beginning of today's revolution in EO, and—as of June 10, 2019—these two companies had launched the largest commercial constellations ever with 355 and 103 CubeSats, respectively. The following ones have launched at most seven CubeSats. Therefore, 3 U CubeSats are dominating the scene, and they will over the next decade, followed by far by the 1 U, 2 U, and 6 U form factors (**Figure 5**). However, it is expected that the next wave of growth will be based on 6 U and 12 U CubeSats, which offer the right balance between very capable payloads and limited manufacturing and launch costs.

**Table 2** (extracted from the database in [21]) shows the main companies that have launched CubeSats, the number of launched and planned CubeSats, the year of the first launch, the form factor, the application field, and some technical details. The rows marked in light blue correspond to EO optical imaging, in light green to EO

**149**

**Figure 4.**

from the onboard camera at [24].

*Nanosatellites and Applications to Commercial and Scientific Missions*

passive microwaves applications, in dark green to EO active microwaves applications, and in light orange typically to IoT and M2M communications. In the next sections, we will focus on the EO applications but keeping in mind that future advances in satellite communication networks will also improve the performance of EO systems and enable new ones as well as distributed ones (e.g., large synthetic apertures). The interested reader is encouraged to consult [21] for the most updated information as these numbers can change rapidly. Note that the number of CubeSats that can be launched in a single rocket can be very high. The current record is held by the Indian rocket PSLV-C37 that, on February 15, 2017, launched Cartosat-2D and 103 CubeSats, from which 88 are from the Planet Labs Inc. and 8 are from the Spire Global Inc. The interested reader is invited to see the deployment of these satellites

*The number of nanosatellites launched per year and (a) organization or (b) form factor [21].*

*DOI: http://dx.doi.org/10.5772/intechopen.90039*

*Nanosatellites and Applications to Commercial and Scientific Missions DOI: http://dx.doi.org/10.5772/intechopen.90039*

passive microwaves applications, in dark green to EO active microwaves applications, and in light orange typically to IoT and M2M communications. In the next sections, we will focus on the EO applications but keeping in mind that future advances in satellite communication networks will also improve the performance of EO systems and enable new ones as well as distributed ones (e.g., large synthetic apertures).

The interested reader is encouraged to consult [21] for the most updated information as these numbers can change rapidly. Note that the number of CubeSats that can be launched in a single rocket can be very high. The current record is held by the Indian rocket PSLV-C37 that, on February 15, 2017, launched Cartosat-2D and 103 CubeSats, from which 88 are from the Planet Labs Inc. and 8 are from the Spire Global Inc. The interested reader is invited to see the deployment of these satellites from the onboard camera at [24].

*Satellites Missions and Technologies for Geosciences*

*CubeSat form factors from 1 U to 12 U [20].*

The current CubeSat Design Specification defines the envelopes for 1 U, 1.5 U, 2 U, 3 U and 3 U+, and 6 U form factors (see, e.g., CubeSat Design Specification Rev. 13 or 6 U CubeSat Design Specification in [17], **Figure 3**), and the standardization of 12 U and 16 U is in progress, although some companies have produced standards up to 27 U [18]. On the other side, smaller picosatellites, the so-called PocketQubes,

Probably, what has had the most significant impact in the popularization of the CubeSat standard has been the capability to separate the interface between the spacecraft and the poly-picosatellite orbital deployer (P-POD) and between the dispenser and the rocket itself. There are two different classes of PODs. The first type is the classical one with four rails in the corners [17], and the second one is with tables [18]. Note however that modern deployers from ISIS and NanoRacks allow larger deployables, wider solar panels, and thinner rails as compared to original P-POD, e.g., increased extruded height up to 9 mm and up to 2 kg per 1 U.

As of June 2019, 64 countries have launched nanosatellites or CubeSats. The total number of nanosatellites launched is 1186, from which 1088 are CubeSats. Most of them (273) have been launched from the International Space Station at ~400 km orbital height with an inclination of 51.6° and the rest at low Earth orbits (LEO) typically at 500 km sun-synchronous orbit (SSO) with an inclination of 97.5° (217 CubeSats) and 580 km height with 97.8° inclination (80 CubeSats). So far, only two

**Figure 4** shows the number of nanosatellites launched per year (a) and organization, either companies, universities, space agencies, etc., or (b) form factor from

As it can be appreciated, until 2013 most CubeSats were launched by universities

and research institutes, and most of them were 1 U or 2 U. However, in 2013 the first 3 U CubeSats from the Planet Labs Inc. [22] and Spire Global Inc. [23] were launched. That was the beginning of today's revolution in EO, and—as of June 10, 2019—these two companies had launched the largest commercial constellations ever with 355 and 103 CubeSats, respectively. The following ones have launched at most seven CubeSats. Therefore, 3 U CubeSats are dominating the scene, and they will over the next decade, followed by far by the 1 U, 2 U, and 6 U form factors (**Figure 5**). However, it is expected that the next wave of growth will be based on 6 U and 12 U CubeSats, which offer the right balance between very capable payloads

**Table 2** (extracted from the database in [21]) shows the main companies that have launched CubeSats, the number of launched and planned CubeSats, the year of the first launch, the form factor, the application field, and some technical details. The rows marked in light blue correspond to EO optical imaging, in light green to EO

about 1/8 the size of a CubeSat, have also been standardized [19].

(MarCO-1 and MarCO-2) have performed interplanetary missions.

**148**

**1.3 Current status**

**Figure 3.**

picosats, 0.25 up to 16 U.

and limited manufacturing and launch costs.

#### **Figure 5.**

*The number of CubeSats by form factor [21].*


**151**

*Nanosatellites and Applications to Commercial and Scientific Missions*

**Analytical Space** 1/N/A 2018 6 U IoT/M2M,

**AISTech** 2/150 2018 2 U, 6 U IoT/M2M,

**Reaktor Space** 1/36 2018 6 U, 2 U Earth

**First launch**

**Form factor**

**NanoAvionics** 2/72 2017 6 U, 12 U IoT/M2M Global IoT constellation-as-

**Helios Wire** 2/30 2017 6 U, 16 U IoT/M2M Uses 30 MHz of S-band

2/140 2018 3 U, 6 U IoT/M2M,

**Hiber** 2/48 2018 6 U IoT/M2M Sends small packets of

**Guodian Gaoke** 2/38 2018 6 U IoT/M2M Reliable and economical

**Astrocast** 2/80 2018 3 U IoT/M2M Targeting L-band. Inter-

**ICEYE** 2/18 2018 Microsat SAR 21-launch agreement with

**Harris Corp.** 1/12 2018 6 U Weather Immediate access to 3D wind

**SIRION** 1/N/A 2018 CubeSat IoT/M2M IoT/M2M constellation.

**Myriota** 1/50 2018 CubeSat IoT/M2M Run unique, patented

Internet

orbital data relay, optical comms.

ADS-B, AIS, IR imaging

observation, hyperspectral

**Field Technical and comments**

a-service system aimed at IoT/M2M communication providers

spectrum to receive tiny data packages from billions of sensors

IoT/M2M data communication network. Monthly fee based on the data amount. Hope to achieve rates of 1–40 Mbps

In-orbit relays receiving radio and downlink to ground with laser communication enabling more data downlink from satellites

data (140 characters, accompanied by time stamp, identifier, and location)

satellite IoT services and industry solutions for our customers

satellite links. NanoSpace propulsion. Further 80 satellites in orbit by 2022

Two-way comms., thermal imaging to detect forest fires, aviation tracking (ADS-B)

Vector Space Systems. 10-platform agreement with York Space Systems

data sets from Harris-owned HyperCubes

Partnered closely with Helios Wire. Sharing spectrum and satellites

Hyperspectral constellation for smart agriculture with 100's of spectral bands and 20 m resolution

software which provides reliable, direct-to-satellite Internet of Things (IoT) connectivity

*DOI: http://dx.doi.org/10.5772/intechopen.90039*

**planned size**

**Organization Launched/**

**Kepler Communications**

#### *Nanosatellites and Applications to Commercial and Scientific Missions DOI: http://dx.doi.org/10.5772/intechopen.90039*

*Satellites Missions and Technologies for Geosciences*

**Organization Launched/**

*The number of CubeSats by form factor [21].*

**Figure 5.**

**planned size**

**First launch**

**Planet Labs** 355/150 2013 3 U Earth

**Spire** 103/150 2013 3 U Weather,

**Form factor**

**AprizeSat** 12/12 2002 Microsat IoT/M2M Low-cost satellite data

**GeoOptics** 7/N/A 2017 6 U Weather Using GPS radio occultation

1 U

6 U, 3 U

1.5 U

3 U

7/150 2018 0.25 U,

3/200 2017 8 U, 6 U,

**Commsat** 7/72 2018 Microsat,

**Fleet Space** 4/100 2018 3 U, 12 U,

**Astro Digital** 6/25 2014 6 U, 16 U Earth

observation

AIS, ADS-B, earthquake

IoT/M2M, AIS

observation

**Field Technical and comments**

29 MP sensor taking images with 3.7 m ground resolution and swath of 24.6 km × 16.4 km from 475 km altitude

Measure change in GPS signal after passing atmosphere to calculate precise profiles for temperature, pressure, and humidity. Investigating earthquake (ELF) detection

services for monitoring the fuel level and oil and gas pipelines and mobile tracking of shipping containers, railcars, and trailers

for weather data

communication satellites

Ladybeetle 1 is 100 kg and 3 CubeSats of 6 U and 3 of 3 U. Plans 4 more in 2019 and complete 72 satellites in 2022

6 U has 22 m resolution in RGB and NIR. 16 U has 2.5 m resolution in RGB, red edge, and NIR with 70 MP sensor

with 12 U CubeSats

(voice, data, and M2M). Plans to use inter-satellite links

IoT/M2M World's smallest two-way

IoT/M2M Main constellation potentially

IoT/M2M Communication service

**150**

**Sky and Space Global**

**Swarm Technologies**



*Blue for constellations for optical EO, light green for passive microwave EO, dark green for active microwave EO, and orange for IoT and M2M communications.*

#### **Table 2.**

*The main existing and planned CubeSats and microsat commercial constellations.*

#### **2. Science opportunities**

As illustrated in **Table 2**, by 2010 the maturity achieved by CubeSats and dispensers/launchers, on one side, and by some EO technologies (high-resolution multispectral imagery and GNSS-RO), on the other side, made possible that a number of companies developed applications based on commercial constellations. Today, thanks to an intense technology R&D, the situation is completely different.

The reasons for this have been threefold. On one side, due to their small size, it has been difficult to include deployable solar panels so as to increase the electrical power generated, and, on the other side, it has been difficult to include large antenna reflectors and to transmit enough RF power so as to have a satisfactory space-to-Earth link budget. The third reason was the poor pointing accuracy that now has significantly improved thanks to miniaturized star trackers and reaction wheels. So far, these reasons have kept active optical (LIDAR) and active microwave sensors (RADAR) away from CubeSats, although it has to be stated that synthetic aperture radars (SAR) have been recently boarded in microsatellite platforms successfully (ICEYE, **Table 2**).

For spaceborne EO applications, frequency bands are restricted to those in which the atmosphere exhibits a high transmissivity, that is, the microwave and millimeter-wave parts of the radio spectrum and the long-wave infrared (LWIR), near infrared (NIR), and visible (VIS) parts of the spectrum, as illustrated in **Figure 6**.

For astronomical observations, ground-based observations are also limited to Earth's atmospheric windows in the radio and optical parts of the spectrum (**Figure 6**). Therefore, to explore the remaining parts of the EM spectrum, spacebased observatories are required.

**153**

*Nanosatellites and Applications to Commercial and Scientific Missions*

In any case, either for EO or astronomical observations, the lower cost of individual CubeSat-based missions allows having more units, which reduces the revisit

○ Space telescopes allow access to energies across the whole electromagnetic spectrum avoiding large gaps in the radio, far IR, and the entire high-energy

○ Feasibility to conduct time domain programs, which are very challenging with flagship missions such as the Hubble Space Telescope and James Webb

○ Heliophysics, e.g., measurement of plasma processes in the magnetosphere-

○ Planetary science: in situ investigation of planetary surfaces or atmospheres.

○ Astronomy and astrophysics: low-frequency radio science and the search for

• Biological and physical sciences, e.g., survival and adaptation of organisms to space

Since the CubeSat standard was proposed in 1999, it took about a decade for NASA to start the Educational Launch of Nanosatellites (ELaNa) initiative in 2010. Partnerships were established with universities in the USA to design and launch CubeSats through NASA's CubeSat Launch Initiative (CSLI). Since then, 85 CubeSat missions have flown on 25 ELaNa calls, and 34 more CubeSats are manifested in 4 more calls. While it provides NASA with valuable opportunities to test emerging technologies that may be useful in future space missions, university students get involved in all phases of the mission, from the instrument and satellite design to its launch and monitoring.

**2.1 NASA science and technology strategy using CubeSats**

time at a given cost. This offers a number of new science opportunities [26]:

○ Multipoint high temporal resolution of Earth processes

*DOI: http://dx.doi.org/10.5772/intechopen.90039*

*Electromagnetic spectrum with different bands indicated [25].*

• Earth science:

**Figure 6.**

• Astrophysics:

○ Mitigation of data gaps

○ Continuous monitoring

range (UV to γ-rays).

Space Telescope.

ionosphere system.

extrasolar planets.

*Nanosatellites and Applications to Commercial and Scientific Missions DOI: http://dx.doi.org/10.5772/intechopen.90039*

**Figure 6.**

*Satellites Missions and Technologies for Geosciences*

**planned size**

**ADASpace** 1/192 2018 Microsat

**First launch**

**LaserFleet** 1/192 2018 CubeSat Internet,

*The main existing and planned CubeSats and microsat commercial constellations.*

**Form factor**

CubeSat

**Lacuna Space** 1/32 2019 3 U, 6 U IoT/M2M IoT/M2M constellation.

*Blue for constellations for optical EO, light green for passive microwave EO, dark green for active microwave EO, and* 

optical comms.

Earth observation

1/40 2019 3 U Weather Weather constellation utilizes

**Field Technical and comments**

Provide reliable 1 Gbps communication rates to aircraft at altitude. Higher effective data rate at a lower cost than the best-in-class Ku/Ka/V

Establish a global, minutelevel updated Earth image data network consisting of 192 satellites

microwave technology to capture temperature and moisture measurements, refreshed and delivered every 15 minutes

Selected Open Cosmos to build 3 U demonstrator

**Organization Launched/**

**Orbital Micro Systems**

**2. Science opportunities**

*orange for IoT and M2M communications.*

cessfully (ICEYE, **Table 2**).

based observatories are required.

different.

**Table 2.**

As illustrated in **Table 2**, by 2010 the maturity achieved by CubeSats and dispensers/launchers, on one side, and by some EO technologies (high-resolution multispectral imagery and GNSS-RO), on the other side, made possible that a number of companies developed applications based on commercial constellations. Today, thanks to an intense technology R&D, the situation is completely

The reasons for this have been threefold. On one side, due to their small size, it has been difficult to include deployable solar panels so as to increase the electrical power generated, and, on the other side, it has been difficult to include large antenna reflectors and to transmit enough RF power so as to have a satisfactory space-to-Earth link budget. The third reason was the poor pointing accuracy that now has significantly improved thanks to miniaturized star trackers and reaction wheels. So far, these reasons have kept active optical (LIDAR) and active microwave sensors (RADAR) away from CubeSats, although it has to be stated that synthetic aperture radars (SAR) have been recently boarded in microsatellite platforms suc-

For spaceborne EO applications, frequency bands are restricted to those in which the atmosphere exhibits a high transmissivity, that is, the microwave and millimeter-wave parts of the radio spectrum and the long-wave infrared (LWIR), near infrared (NIR), and visible (VIS) parts of the spectrum, as illustrated in

For astronomical observations, ground-based observations are also limited to Earth's atmospheric windows in the radio and optical parts of the spectrum (**Figure 6**). Therefore, to explore the remaining parts of the EM spectrum, space-

**152**

**Figure 6**.

*Electromagnetic spectrum with different bands indicated [25].*

In any case, either for EO or astronomical observations, the lower cost of individual CubeSat-based missions allows having more units, which reduces the revisit time at a given cost. This offers a number of new science opportunities [26]:

	- Multipoint high temporal resolution of Earth processes
	- Mitigation of data gaps
	- Continuous monitoring
	- Space telescopes allow access to energies across the whole electromagnetic spectrum avoiding large gaps in the radio, far IR, and the entire high-energy range (UV to γ-rays).
	- Feasibility to conduct time domain programs, which are very challenging with flagship missions such as the Hubble Space Telescope and James Webb Space Telescope.
	- Heliophysics, e.g., measurement of plasma processes in the magnetosphereionosphere system.
	- Planetary science: in situ investigation of planetary surfaces or atmospheres.
	- Astronomy and astrophysics: low-frequency radio science and the search for extrasolar planets.

#### **2.1 NASA science and technology strategy using CubeSats**

Since the CubeSat standard was proposed in 1999, it took about a decade for NASA to start the Educational Launch of Nanosatellites (ELaNa) initiative in 2010. Partnerships were established with universities in the USA to design and launch CubeSats through NASA's CubeSat Launch Initiative (CSLI). Since then, 85 CubeSat missions have flown on 25 ELaNa calls, and 34 more CubeSats are manifested in 4 more calls. While it provides NASA with valuable opportunities to test emerging technologies that may be useful in future space missions, university students get involved in all phases of the mission, from the instrument and satellite design to its launch and monitoring.

As early as 2012, NASA's Science Mission Directorate (SMD) technology programs began to accommodate the use of CubeSats for validation of new science instruments and strategically promoted the use of small spacecraft to advance its science portfolio.

On one side, the Earth Science Technology Office (ESTO), which is responsible for identifying and developing technologies in support of future Earth Science Division missions, manages three major observation technology programs that solicit new awards on a 2–3-year selection cycle, as shown in **Table 3** [27].

And on the other side, following the outcomes of [28] in 2014, the Planetary Science Division (PSD) has also made significant strides toward accommodating small satellites for exploration of the solar system and for astrophysics research. **Table 4** [27] summarizes the three main planetary science technology programs.

The result of these continued investments is summarized in **Table 5**, where a number of EO techniques that were infeasible in 2012 [29] were all feasible 5 years later [30], many of them demonstrated by CubeSat missions, some of them commercial, and some even operational constellations. CubeSat-based astronomy missions will be discussed later.

**Figure 7** illustrates some of these NASA CubeSat-based EO missions. They follow the 3 U or 6 U form factor and include deployable solar panels for higher electrical power generation capabilities. RainCube (**Figure 7c**) also includes a 0.5-m-diameter deployable Ka band that stows in 1.5 U. This antenna has a gain of 42.6 dBi, and it was optimized for the radar frequency of 35.75 GHz. References are provided for more information on the cited missions.


#### **Table 3.**

*Earth science technology programs relevant to small satellites [27].*


**155**

*Nanosatellites and Applications to Commercial and Scientific Missions*

**by Selva and Krejci** 

**2017 technology review by Freeman et al.**

Problematic Feasible PICASSO, IR sounders

Feasible Feasible SERB, RAVAN

Problematic Feasible AstroDigital

Problematic Feasible TEMPEST

Problematic Feasible HARP Polarimeter

Feasible Feasible —

Cloud profile and rain radars Infeasible Feasible JPL RainCube demo

Gravity instruments Feasible Feasible No demo mission Hi-res optical imagers Infeasible Feasible Planet Labs. Imaging microwave radars Infeasible Problematic Ka-Band 12 U design

Lidars Infeasible Problematic DIAL laser occultation

Precision orbit Feasible Feasible CanX-4 and CanX-5 Radar altimeters Infeasible Feasible Bistatic LEO-GEO/

Scatterometers Infeasible Feasible CYGNSS (GNSS-R)

Lightning imagers Feasible Feasible — Magnetic field Feasible Feasible InSPIRE

Ocean color instruments Feasible Feasible SeaHawk

**Justification**

MEO

**2.2 ESA science and technology strategy using CubeSats**

*Artist's view of (a) TEMPEST [31], (b) RAVAN [32], and (c) RainCube missions [33].*

editions of the "Fly Your Satellite!" program.

On the educational side, the ESA launched in February 2008 the first Call for CubeSat Proposals to universities in ESA member and cooperating states. Seven student-built CubeSats were launched onboard the Vega maiden flight on February 13, 2012. Since then, 12 more CubeSats have been enrolled in the first and second

Since 2013, the ESA has invested more than 16 M€ as part of the General Support Technology Program (GSTP) FLY Element [34], in 12 CubeSat IOD missions [35, 36]. As part of ESA's Systems Department Project Office of the Systems

*DOI: http://dx.doi.org/10.5772/intechopen.90039*

Atmospheric chemistry

Atmospheric temperature and humidity sounders

Earth radiation budget

Imaging multispectral radiometers (Vis/IR)

Imaging multispectral radiometers (μW)

Multiple direction/ polarization radiometers

*In red: commercial companies.*

*EO technologies for CubeSat-based missions [29, 30].*

**Table 5.**

**Figure 7.**

instruments

radiometers

**Technology 2012 technology review** 

#### **Table 4.**

*Planetary science technology programs relevant to small satellites [27].*

*Nanosatellites and Applications to Commercial and Scientific Missions DOI: http://dx.doi.org/10.5772/intechopen.90039*


#### **Table 5.**

*Satellites Missions and Technologies for Geosciences*

missions will be discussed later.

Instrument Incubator

Advanced Components

In-Space Validation of Earth Science Technologies (InVEST)

Planetary Instrument Concepts for the Advancement of Solar System Observations (PICASSO)

Maturation of Instruments for Solar System Exploration

Development and Advancement of Lunar Instruments (DALI)

(MatISSE)

(IIP)

(ACT)

**Table 3.**

provided for more information on the cited missions.

*Earth science technology programs relevant to small satellites [27].*

*Planetary science technology programs relevant to small satellites [27].*

**Planetary science program Approx. funding Description**

**Earth science program Approx. funding Description**

As early as 2012, NASA's Science Mission Directorate (SMD) technology programs began to accommodate the use of CubeSats for validation of new science instruments and strategically promoted the use of small spacecraft to advance its science portfolio. On one side, the Earth Science Technology Office (ESTO), which is responsible for identifying and developing technologies in support of future Earth Science Division missions, manages three major observation technology programs that solicit new awards on a 2–3-year selection cycle, as shown in **Table 3** [27].

And on the other side, following the outcomes of [28] in 2014, the Planetary Science Division (PSD) has also made significant strides toward accommodating small satellites for exploration of the solar system and for astrophysics research. **Table 4** [27] summarizes the three main planetary science technology programs. The result of these continued investments is summarized in **Table 5**, where a number of EO techniques that were infeasible in 2012 [29] were all feasible 5 years later [30], many of them demonstrated by CubeSat missions, some of them commercial, and some even operational constellations. CubeSat-based astronomy

**Figure 7** illustrates some of these NASA CubeSat-based EO missions. They follow the 3 U or 6 U form factor and include deployable solar panels for higher electrical power generation capabilities. RainCube (**Figure 7c**) also includes a 0.5-m-diameter deployable Ka band that stows in 1.5 U. This antenna has a gain of 42.6 dBi, and it was optimized for the radar frequency of 35.75 GHz. References are

\$28 M/year Nurtures the development and assessment of

\$5 M/year Enables the research, development, and

CubeSats

to mid-stage development)

\$5 M/year Advances the readiness of existing Earth science-

innovative remote sensing concepts in ground, aircraft, or engineering model demonstrations (early

demonstration of component- and subsystem-level technologies to reduce the risk, cost, size, mass, and development time of missions and infrastructure

related technology and reduces risks to future missions through space flight validation using

\$4 M/year Supports the development of spacecraft-based

\$6 M/year Supports the advanced development of

\$5 M/year Supports the development of science

technology readiness

instrument components and systems that show promise for future planetary missions. The program supports early-stage technologies

spacecraft-based instruments that may be proposed for future planetary missions that are at the middle stages of technology readiness

instruments for small lunar landers and orbital assets that are at the middle stages of

**154**

**Table 4.**

*EO technologies for CubeSat-based missions [29, 30].*

**Figure 7.**

*Artist's view of (a) TEMPEST [31], (b) RAVAN [32], and (c) RainCube missions [33].*

#### **2.2 ESA science and technology strategy using CubeSats**

On the educational side, the ESA launched in February 2008 the first Call for CubeSat Proposals to universities in ESA member and cooperating states. Seven student-built CubeSats were launched onboard the Vega maiden flight on February 13, 2012. Since then, 12 more CubeSats have been enrolled in the first and second editions of the "Fly Your Satellite!" program.

Since 2013, the ESA has invested more than 16 M€ as part of the General Support Technology Program (GSTP) FLY Element [34], in 12 CubeSat IOD missions [35, 36]. As part of ESA's Systems Department Project Office of the Systems Department, Directorate of Technical and Engineering Quality, in April 2019, the CubeSat Systems Unit was created.

In addition to the work conducted by this unit, there are a number of other CubeSat-related initiatives in ESA:


The first ESA CubeSat projects are listed in **Table 6**. In addition to these missions, numerous studies have focused on the applications of CubeSat missions and

#### **Figure 8.**

*Artist's view of (a) GOMX-3 [35] and (b) GOMX-4 [36] nanosatellites in space (credits GomSpace) and (c) FSSCat mission [38, 39].*

**157**

**Table 6.**

**RMI (BE) KU Leuven (BE)**

**BIRA-IASB (BE) VTT (FI) Clyde Space (UK)**

**C3S and MTA EK (HU) ICL (UK) Astronika (PO)**

**RUAG (AU) TU Graz (AU) Seibersdorf Labor GmbH (AU)**

**UPC (ES) Golbriak (EE) Deimos Eng (PT)**

**Tyvak Intl. (IT) Cosine (NL)**

*Copernicus Masters Competition).*

*The first ESA CubeSat-based missions.*

*Nanosatellites and Applications to Commercial and Scientific Missions*

**GomSpace (DK)** GOMX-4B 2018 2 × 6 U Tech demo

miniaturized payloads, including remote sensing with cooperative nanosatellites, asteroid impact missions, lunar CubeSats, astrobiology/astrochemistry experiment

**factor**

**VKI (BE)** Qarman 2019 3 U Tech demo Demonstrates reentry

SIMBA 2019 3 U Earth

PICASSO 2019 3 U Atmosphere

RadCube 2019 3 U Tech demo

PRETTY — 3 U Earth

**ESA** OPS-SAT 2019 3 U Tech demo Experimentation with

FSSCat 2019 2 × 6 U Tech demo

*In blue from the CubeSat Systems Unit, Directorate of Technical and Engineering Quality; in orange from the Directorate of Operations; and in green from the Directorate of Earth Observation (2017 ESA S^3 Challenge,* 

Earth observation

observation

and ionosphere

Space weather

observation

Earth observation

**GomSpace (DK)** GOMX-3 2015 3 U Tech demo ADS-B, GEO Satcom

**Field Technical and comments**

signal monitoring, X-band transmitter (**Figure 8a**)

Inter-satellite link and propulsion while in tandem with GOMX-4A (GomSpace, Ministry of Defense, DK), star tracker HyperScout compact hyperspectral VNIR imager (Cosine, NL) (**Figure 8b**)

technologies, novel heatshield materials, new passive aerodynamic drag stabilization system, and telemetry transmission during reentry via data relay satellites in low Earth orbit

Total solar irradiance and Earth radiation budget

Stratospheric ozone distribution, mesospheric temperature profile, and ionospheric electron density

3 U platform In situ space radiation and magnetic field in LEO

GNSS-R at low grazing angles, radiation dosimeter

onboard and ground software by offering a safe and reconfigurable environment

RF and O-ISL, federated satellite experiment

Cat-5/A: Microwave radiometer and GNSS-R (UPC, ES)

Cat-5/B: HyperScout-2 VNIR + TIR hyperspectral imager (Cosine, NL) (**Figure 8c**)

3

3

*DOI: http://dx.doi.org/10.5772/intechopen.90039*

CubeSats, asteroid observer missions, etc.

**Organization Mission Launch Form** 

*Satellites Missions and Technologies for Geosciences*

for innovative mission control software.

and navigation to a sample container from the orbit.

CubeSats in support of planetary science missions.

with artificial intelligence for cloud detection (PhiSat-1).

CubeSat Systems Unit was created.

CubeSat-related initiatives in ESA:

Department, Directorate of Technical and Engineering Quality, in April 2019, the

In addition to the work conducted by this unit, there are a number of other

• The Directorate of Telecommunications and Integrated Applications is developing a pioneer series of CubeSat missions, to test novel telecommunication technologies.

• The Directorate of Operations has OPS-SAT [37] ready to fly, an IOD test-bed

• The Directorate of Human and Robotic Exploration is considering a CubeSat mission to test out a key capability for Mars sample return optical detection

• The Science Directorate is also adapting some CubeSat technologies for operation in the deep space environment as well as studying the potential use of

• The Directorate of Earth Observation will fly FSSCat [38, 39], a double 6 U CubeSat mission for tandem observation of the polar regions and for soil moisture mapping using the FMPL-3 (UPC, ES), a combined L-band microwave radiometer and GNSS-Reflectometer using a software-defined radio, and HyperScout-2 (Cosine, NL), a VNIR and TIR hyperspectral imager enhanced

The first ESA CubeSat projects are listed in **Table 6**. In addition to these missions, numerous studies have focused on the applications of CubeSat missions and

*Artist's view of (a) GOMX-3 [35] and (b) GOMX-4 [36] nanosatellites in space (credits GomSpace) and* 

**156**

**Figure 8.**

*(c) FSSCat mission [38, 39].*

miniaturized payloads, including remote sensing with cooperative nanosatellites, asteroid impact missions, lunar CubeSats, astrobiology/astrochemistry experiment CubeSats, asteroid observer missions, etc.


*In blue from the CubeSat Systems Unit, Directorate of Technical and Engineering Quality; in orange from the Directorate of Operations; and in green from the Directorate of Earth Observation (2017 ESA S^3 Challenge, Copernicus Masters Competition).*

#### **Table 6.**

*The first ESA CubeSat-based missions.*

#### **3. Astronomy and interplanetary missions using CubeSats**

As highlighted in Sections 1.3 and 2.1, the majority of the CubeSats orbiting today are devoted to Earth observation, notably from two commercial companies, followed by communications. In the coming years, these two categories will still dominate. Although the largest increase will occur in communication satellites, the growth in scientific (non-EO) missions will not be negligible (from 10 to 20%, **Figure 9**) considering that the predicted number of satellites to be launched is going to multiply by more than a factor of 3 (see **Figure 4**).

In particular, until 2017 there were only 5 astronomy missions, and in the field interplanetary missions, until 2018 only 14 nano−/microsatellites had been launched to destinations outside the LEO. Beyond-the-Earth orbit is the domain of civil agencies who, for the sake of reliability, have been historically reluctant to invest in small satellites. However, things may be changing, since only in 2018 four nano−/microsatellites made their way beyond the Earth orbit, which is more than those in the previous 5 years all together, and 35 more are expected to be launched in the coming 5 years. Naturally, most of them target the moon, but a non-negligible fraction will be devoted to interplanetary missions (**Figure 10**).

As in other fields, at the beginning all the astronomy or heliophysics missions were conducted by universities, and it was not until 2017 that the first NASA JPL mission (ASTERIA) was launched. Achieving state-of-the-art astronomy with CubeSats has become possible due to advances in precision pointing, communications technology, and deployables, among others (Tables 5.1 and 5.2 of [40]). **Table 7**, distilled from [21], shows the main astronomy and beyond-the-Earth past and planned missions. It also shows that the majority of these missions are based on the 6 U form factor, which is the smallest one capable to accommodate all the advanced attitude determination and control systems (ADCS), larger deployable solar panels and antennas, as well as telescope optics. It is also remarkable that so far there are no funded CubeSat missions in the far IR because the thermal stability and detector cooling require cryo-coolers for CubeSats that have yet to be developed for astrophysics due to power and space limitations [41].

It is worth noting that the large number of CubeSats to be launched to the Moon in 2020 corresponds to the Artemis-1 mission (**Figure 11**), formerly known as Exploration Mission-1. The first mission for NASA's Orion rocket and the European Service Module will send the spacecraft beyond the moon and back. Thirteen low-cost CubeSat missions were competitively selected as secondary payloads on the Artemis-1 test flight, all of them having the 6 U form factor. The selected CubeSats are Lunar Flashlight, Lunar South Pole, Near-Earth Asteroid Scout,

**159**

*Nanosatellites and Applications to Commercial and Scientific Missions*

*CubeSats launched beyond the earth orbit: 14 from 2003 to 2018 and 35 planed from 2019 to 2023 (adapted* 

**factor**

8 U (2 × 2 × 2)

CXBN 2012 2 U • Cosmic X-ray background (CXRB)

CSSWE 2012 3 U • Measures the directional differential

MinXSS 2015 3 U • Provides spectral observations of

ASTERIA 2017 6 U • Detects exoplanetary transits across

PicSat 2018 3 U • To observe in visible light the

**Technical and comments**

in the 30–50 keV range

• BRITE Target Explorer Constellation: BRITE-Toronto, BRITE-Heweliusz, UniBRITE, BRITE-Austria, BRITE-Lem, BRITE-Montreal • Conducts photometric observations of some of the brightest stars in the sky to examine their variability. Observations will have a precision at least 10x better than achievable from ground-based

electrons

observations

bright stars

orbit

the solar X-rays near the maximum of solar cycle 24 from 0.6 keV (20 Å) to 25 keV (0.5 Å)

• Pointing accuracy of ±0.003° (1σ) for 2 axes and ± 0.007° (1σ) for the third axis, with 0.5″ rms over 20 min, pointing repeatability of 0.001″ rms from orbit to

• ±0.01 K level temperature stability of the imaging detector

potential transit of the • directly imaged giant planet β Pictoris b and perhaps even its

moons and debris

flux of solar energetic protons (SEPs) and Earth's radiation belt

*DOI: http://dx.doi.org/10.5772/intechopen.90039*

**Organization Mission Launch Form** 

BRITE 2013

2014

**Figure 10.**

*from [14]).*

**Morehead State University Kentucky Space**

**University of Colorado**

**University of Colorado at Boulder**

**JPL (USA) MIT (USA)**

**ERC, CNRS, ESEP Lab, PSL Université Paris, Fondation MERAC, CNES, CCERES and Obs. de Paris – LESIA**

**Austria Canada Poland**

**Figure 9.** *Satellite application trends (1–50 kg): (a) 2014–2018 and (b) 2019–2023 (adapted from [14]).*

#### *Nanosatellites and Applications to Commercial and Scientific Missions DOI: http://dx.doi.org/10.5772/intechopen.90039*

#### **Figure 10.**

*Satellites Missions and Technologies for Geosciences*

to multiply by more than a factor of 3 (see **Figure 4**).

fraction will be devoted to interplanetary missions (**Figure 10**).

**3. Astronomy and interplanetary missions using CubeSats**

As highlighted in Sections 1.3 and 2.1, the majority of the CubeSats orbiting today are devoted to Earth observation, notably from two commercial companies, followed by communications. In the coming years, these two categories will still dominate. Although the largest increase will occur in communication satellites, the growth in scientific (non-EO) missions will not be negligible (from 10 to 20%, **Figure 9**) considering that the predicted number of satellites to be launched is going

In particular, until 2017 there were only 5 astronomy missions, and in the field interplanetary missions, until 2018 only 14 nano−/microsatellites had been launched to destinations outside the LEO. Beyond-the-Earth orbit is the domain of civil agencies who, for the sake of reliability, have been historically reluctant to invest in small satellites. However, things may be changing, since only in 2018 four nano−/microsatellites made their way beyond the Earth orbit, which is more than those in the previous 5 years all together, and 35 more are expected to be launched in the coming 5 years. Naturally, most of them target the moon, but a non-negligible

As in other fields, at the beginning all the astronomy or heliophysics missions were conducted by universities, and it was not until 2017 that the first NASA JPL mission (ASTERIA) was launched. Achieving state-of-the-art astronomy with CubeSats has become possible due to advances in precision pointing, communications technology, and deployables, among others (Tables 5.1 and 5.2 of [40]). **Table 7**, distilled from [21], shows the main astronomy and beyond-the-Earth past and planned missions. It also shows that the majority of these missions are based on the 6 U form factor, which is the smallest one capable to accommodate all the advanced attitude determination and control systems (ADCS), larger deployable solar panels and antennas, as well as telescope optics. It is also remarkable that so far there are no funded CubeSat missions in the far IR because the thermal stability and detector cooling require cryo-coolers for CubeSats that have yet to be developed for astrophysics due to power and space limitations [41]. It is worth noting that the large number of CubeSats to be launched to the Moon

in 2020 corresponds to the Artemis-1 mission (**Figure 11**), formerly known as Exploration Mission-1. The first mission for NASA's Orion rocket and the European Service Module will send the spacecraft beyond the moon and back. Thirteen low-cost CubeSat missions were competitively selected as secondary payloads on the Artemis-1 test flight, all of them having the 6 U form factor. The selected CubeSats are Lunar Flashlight, Lunar South Pole, Near-Earth Asteroid Scout,

*Satellite application trends (1–50 kg): (a) 2014–2018 and (b) 2019–2023 (adapted from [14]).*

**158**

**Figure 9.**

*CubeSats launched beyond the earth orbit: 14 from 2003 to 2018 and 35 planed from 2019 to 2023 (adapted from [14]).*



**161**

Escape Explorer (CU-E3

beyond-LEO CubeSat exploration initiatives.

*Nanosatellites and Applications to Commercial and Scientific Missions*

**factor**

Lunar IceCube 2020 6 U • Prospects for water ice and other

SPARCS 2021 6 U • Monitoring in the far (153–171 nm)

BurstCube 2021 6 U • Detection of gamma ray transients

M-ARGO 2023 12 U • Demonstrating asteroid rendezvous

**NASA JPL** Lunar Flashlight 2020 6 U • Illuminates with lasers in four

**Technical and comments**

near-infrared

surface

mission

wave sources

mission

altimeter

N/A 2x6 U • Observing asteroid and deflection assessment

different bands the permanently shadowed regions and detect water ice absorption bands in the

lunar volatiles as a function of time of day, latitude, and regolith composition/mineralogy from a low-perigee lunar orbit flying only 100 km (62 miles) above the lunar

and near UV (258–308 nm) of lowmass stars (0.2–0.6 Mʘ); the most dominant hosts of exoplanets • Each star observed for at least one stellar rotation (4–45 days) • Third NASA-funded astronomy

in the 10–1000 keV energy range. Valuable capability to catch the predicted counterparts of gravitational

• Fourth NASA-funded astronomy

and identifying in situ resources with multispectral imager and laser

BioSentinel (carrying the first living creatures into deep space since 1972), SkyFire, Lunar IceCube, CubeSat for Solar Particles (CuSP), Lunar Polar Hydrogen Mapper (LunaH-Map), EQUULEUS, OMOTENASHI, ArgoMoon, Cislunar Explorers, Earth

Talking about interplanetary missions, on May 5, 2018, NASA launched a stationary lander called InSight to Mars. InSight landed on Mars on November 26, 2018. Riding along with InSight were two CubeSats—the first of this kind of spacecraft ever to fly to deep space [42]. Both MarCO-A and MarCO-B succeeded in a flyby of Mars, relaying data to Earth from InSight as it landed on Mars. **Figure 12** shows an artist view of the MarCOs with the reflectarray used for communication purposes. In addition to the "classical" astronomy, lunar and Martian missions cited above, CubeSats are nowadays finding their way to other bodies of the solar system, and there are proposals [43] to send them to Venus (CUVE mission), Deimos and Phobos asteroids (PRISM and PROME missions), comets (PrOVE mission), or Jupiter (ExCSITE mission, [44]). **Figure 13** from [44] illustrates the LEO and

), and Team Miles.

*Non-comprehensive list of astronomy and beyond-the-earth CubeSat-based missions.*

*DOI: http://dx.doi.org/10.5772/intechopen.90039*

**Morehead State University**

**Arizona State University (USA)**

**NASA's Goddard Space Flight Center**

**Luxembourg Space Agency (LU) GomSpace (DK)**

**ESA** HERA

CUBESAT

**ESA**

**Table 7.**

**Organization Mission Launch Form** 


#### *Nanosatellites and Applications to Commercial and Scientific Missions DOI: http://dx.doi.org/10.5772/intechopen.90039*

#### **Table 7.**

*Satellites Missions and Technologies for Geosciences*

**University of Colorado Boulder**

**University of Colorado**

**NASA** MarCO-1/

**University of Hawaii** 

**at Manoa**

**University of Colorado Boulder**

**Arizona State University**

MarCO-2

**Organization Mission Launch Form** 

**factor**

**University of Iowa** HaloSat 2018 6 U • Measurement of soft X-ray emission

**Spacety (China)** Tongchuan-1 2018 6 U • Detects signals from gamma-ray

MinXSS-2 2018 3 U • As MinXSS

**DARPA** SHFT-1 2018 3 U • Collects radio-frequency signals in

**Boston University** CuPID 2019\* 6 U • Miniaturized soft X-ray imaging

**Isaware (FI)** XFM Cube 2020 3 U • Measuring X-ray fluxes

**Lockheed Martin** LunIR 2020 6 U • Lunar flyby to collect spectroscopy

CSIM 2018 6 U • Observes the solar spectral

NEUTRON-1 2019\* 3 U • Measures low-energy neutron flux

CUTE 2020 6 U • To conduct a survey of exoplanet

LunaH-Map 2020 6 U • High-resolution mapping of hydro-

**Technical and comments**

measurements

gravitational waves

mission

irradiance

2018 6 U • Data relay to send data back to Earth

telescope

mission

from the hot halo of the Milky Way galaxy to resolve the missing baryon problem. Measure O VII and O VIII line emission in 400 fields (FOV ~ 10°) over 90% of the sky. Study of solar wind charge exchange emission to remove uncertainty on the oxygen line emission

• First NASA-funded astronomy

bursts, to identify and locate the electromagnetic counterparts to

the HF (5–30 MHz) band to study the galactic background emissions, the HF signals from Jupiter, and the signals from terrestrial transmitters after having passed through the Earth's ionosphere

during InSight's entry, descent and landing operations at Mars. Technology capability demonstration of communications relay system

transit spectroscopy in the near UV of a dozen short-period, large planets orbiting F,G, and K stars to constrain stellar variability and

and thermography (MWIR sensor) for surface characterization, remote sensing, and site selection

gen content of the entire south pole of the moon, including permanently shadowed regions up to a meter beneath the lunar surface

measure mass loss rates • Second NASA-funded astronomy

in LEO environment

**160**

*Non-comprehensive list of astronomy and beyond-the-earth CubeSat-based missions.*

BioSentinel (carrying the first living creatures into deep space since 1972), SkyFire, Lunar IceCube, CubeSat for Solar Particles (CuSP), Lunar Polar Hydrogen Mapper (LunaH-Map), EQUULEUS, OMOTENASHI, ArgoMoon, Cislunar Explorers, Earth Escape Explorer (CU-E3 ), and Team Miles.

Talking about interplanetary missions, on May 5, 2018, NASA launched a stationary lander called InSight to Mars. InSight landed on Mars on November 26, 2018. Riding along with InSight were two CubeSats—the first of this kind of spacecraft ever to fly to deep space [42]. Both MarCO-A and MarCO-B succeeded in a flyby of Mars, relaying data to Earth from InSight as it landed on Mars. **Figure 12** shows an artist view of the MarCOs with the reflectarray used for communication purposes.

In addition to the "classical" astronomy, lunar and Martian missions cited above, CubeSats are nowadays finding their way to other bodies of the solar system, and there are proposals [43] to send them to Venus (CUVE mission), Deimos and Phobos asteroids (PRISM and PROME missions), comets (PrOVE mission), or Jupiter (ExCSITE mission, [44]). **Figure 13** from [44] illustrates the LEO and beyond-LEO CubeSat exploration initiatives.

#### **Figure 11.**

*Overview of the mission plan for Artemis-1: CubeSats will be deployed at steps A, B, C, and D [https://www. nasa.gov/image-feature/artemis-1-map].*

**Figure 12.** *Artist view of MarCO-A and MarCO-B [42].*

**163**

**Table 8.**

*Nanosatellites and Applications to Commercial and Scientific Missions*

Since its conception in 1999, CubeSats have produced a "disruptive innovation": from simple applications at the bottom of a market (mostly educational), they have relentlessly moved up, eventually displacing established medium-size competing satellites. However, CubeSats cannot displace all the large space missions as physics laws cannot be changed, i.e., large apertures and focal lengths are required to collect faint signals and achieve large angular resolution. However, CubeSats are finding their own niche in many Earth observation, astronomical, and communications applications where short revisit times or even continuous

Early CubeSats typically had short lifetimes once in orbit (a few months), but with increased ground testing and added redundancies, lifetimes have grown

Despite all these outstanding improvements, in order to exploit the full potential of CubeSats, many technologies still need to be developed. **Table 8** summarizes the enabling technologies required for different science applications, indicating in red the most challenging technologies and applications, notably increased communications performance, reliability, thermal stability, and calibration accuracy, to form constellations or formation flying satellite topologies to create large interferometers

Propulsion Constellation deployment and maintenance,

plasmas

Miniaturized sensors Stable, repeatable, and calibrated datasets

Comms&Comms Infrastructure Direct/indirect to Earth communications Radiation-tolerant electronics Enhanced reliability in planetary

Deployables Deployable solar panel enhanced power generation

Propulsion Constellations for interferometry,

Deployables Increased aperture and thermal control

Sub-arcsecond attitude control High-resolution imaging

Miniaturized sensors UV and X-ray imaging

Thermal control Stable payload environment

Communications High data rate

*CubeSat-enabling technologies and potential applications for each science discipline (adapted from [40]).*

Sub-arcsecond attitude control High-resolution solar imaging Communications Missions beyond low Earth orbit

Earth science Propulsion Constellations for high-temporal resolution

Communications High data rates

formation flying

In situ measurements of upper atmosphere

observations and orbit maintenance

magnetospheres, long flights

Deployable mirrors and antennas

distributed apertures

**Science discipline Enabling technology Example application**

Miniature field and plasma

Planetary science Propulsion Orbit insertion

sensors

*DOI: http://dx.doi.org/10.5772/intechopen.90039*

significantly, up to 4–5 years in some cases.

**4. Conclusions and way forward**

monitoring is required.

and distributed apertures.

Solar and space physics

Astronomy and astrophysics

Physical and biological

**Figure 13.** *Solar system exploration with CubeSats and nanosats [44].*

### **4. Conclusions and way forward**

*Satellites Missions and Technologies for Geosciences*

*Overview of the mission plan for Artemis-1: CubeSats will be deployed at steps A, B, C, and D [https://www.*

**162**

**Figure 13.**

**Figure 11.**

**Figure 12.**

*nasa.gov/image-feature/artemis-1-map].*

*Artist view of MarCO-A and MarCO-B [42].*

*Solar system exploration with CubeSats and nanosats [44].*

Since its conception in 1999, CubeSats have produced a "disruptive innovation": from simple applications at the bottom of a market (mostly educational), they have relentlessly moved up, eventually displacing established medium-size competing satellites. However, CubeSats cannot displace all the large space missions as physics laws cannot be changed, i.e., large apertures and focal lengths are required to collect faint signals and achieve large angular resolution. However, CubeSats are finding their own niche in many Earth observation, astronomical, and communications applications where short revisit times or even continuous monitoring is required.

Early CubeSats typically had short lifetimes once in orbit (a few months), but with increased ground testing and added redundancies, lifetimes have grown significantly, up to 4–5 years in some cases.

Despite all these outstanding improvements, in order to exploit the full potential of CubeSats, many technologies still need to be developed. **Table 8** summarizes the enabling technologies required for different science applications, indicating in red the most challenging technologies and applications, notably increased communications performance, reliability, thermal stability, and calibration accuracy, to form constellations or formation flying satellite topologies to create large interferometers and distributed apertures.


#### **Table 8.**

*CubeSat-enabling technologies and potential applications for each science discipline (adapted from [40]).*

In the field of Earth observation, future developments in nanosat sensors will likely occur:

	- Miniature microwave and millimeter-wave radiometers for weather applications, such as the MiniRad which is onboard the Global Environmental Monitoring System (GEMS) constellation from Orbital Micro Systems [45], or
	- GNSS-R instruments with real-time processing for target detection/identification [46] or—as larger downlink bandwidths are available—with raw data acquisition and on-ground processing to optimize the processing according to the target, as planned in FMPL-3, the evolution of the FMPL-2 on board FSSCat [38, 39].

Also, both their calibration will have to be refined so as to improve the quality of the scientific data.

Due to power and antenna size requirements, active microwave sensors (e.g., radar altimeters and SARs) will likely remain in domain of mini- and microsats (< 100 kg, e.g., ICEYE constellation [47]), and it is unlikely that active optical sensor technology (i.e., lidars) develops in small satellites in the midterm.

In the field of astronomy, and in particular heliophysics, NASA has also been taking the lead. In 2017 NASA selected nine proposals under its Heliophysics Small Explorers Program [48]: (1) the Mechanisms of Energetic Mass Ejection Explorer (MEME-X), (2) the Focusing Optics X-ray Solar Imager (FOXSI), (3) the Multi-Slit Solar Explorer (MUSE), (4) the Tandem Reconnection and Cusp Electrodynamics Reconnaissance Satellites (TRACERS), (5) the Polarimeter to Unify the Corona and Heliosphere (PUNCH), (6) the Atmospheric Waves Experiment (AWE), (7) the US Contributions to the THOR mission (THOR-US), (8) the Coronal Spectrographic Imager in the Extreme ultraviolet (COSIE), and (9) the Sun Radio Interferometer Space Experiment (SunRISE) mission concept, which is a space-based sparse array, composed of formation flying of six SmallSats designed to localize the radio emission associated with coronal mass ejections (CMEs) from the sun [49].

More recently, in August 2019, NASA selected two proposals to demonstrate SmallSat technologies to study interplanetary space [50]: (1) Science-Enabling Technologies for Heliophysics (SETH) will demonstrate two technologies, an optical communications technology and experiment to detect solar energetic neutral atoms as well as an array of waves and other particles that erupt from our sun, and (2) Solar Cruiser, which will deploy a nearly 18,000 square foot solar sail and a coronagraph instrument that would enable simultaneous measurements of the sun's magnetic field structure and velocity of coronal mass ejections or CMEs.

As a final thought, quoting Prof. Puig-Suari, "Before cubesats, we were so conservative nobody was willing to try anything out of the ordinary. When we did, we discovered some of the things everybody said would not work, did work. The fundamental change was that there was a mechanism to go try to those things. Some will work and some will not, but it allows us to try them and that was very

**165**

**Author details**

Adriano Camps1,2

Barcelona, Spain

1 CommSensLab "María de Maeztu" Unit, Department of Signal Theory and Communications, Universitat Politècnica de Catalunya UPC-Barcelona Tech,

2 Institut d'Estudis Espacials de Catalunya, IEEC/CTE-UPC, Barcelona, Spain

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

\*Address all correspondence to: camps@tsc.upc.edu

provided the original work is properly cited.

*Nanosatellites and Applications to Commercial and Scientific Missions*

infrequent before cubesats arrived. That was really important. That was the big change." And this is just the beginning of a new way to do Earth observation, astronomy, and satellite communications much more, in a different and more efficient way than it was done in the past decades. What will the future bring? Nobody knows, but certainly the future is being shaped today with these novel technologies,

This work has been supported by an ICREA Acadèmia award from the Generalitat de Catalunya to Prof. A. Camps. The author wants to express his gratitude to Profs. A. Golkar (Skoltech, Moscow, Russia) and H. Park (Universitat Politècnica de Catalunya, Barcelona, Spain) for the revision of this chapter and

*DOI: http://dx.doi.org/10.5772/intechopen.90039*

and only our imagination will set the limits.

**Acknowledgements**

useful comments.

*Nanosatellites and Applications to Commercial and Scientific Missions DOI: http://dx.doi.org/10.5772/intechopen.90039*

infrequent before cubesats arrived. That was really important. That was the big change." And this is just the beginning of a new way to do Earth observation, astronomy, and satellite communications much more, in a different and more efficient way than it was done in the past decades. What will the future bring? Nobody knows, but certainly the future is being shaped today with these novel technologies, and only our imagination will set the limits.

### **Acknowledgements**

*Satellites Missions and Technologies for Geosciences*

Micro Systems [45], or

FSSCat [38, 39].

instead of the raw data.

the scientific data.

• In the field of passive microwave sensors:

likely occur:

In the field of Earth observation, future developments in nanosat sensors will

○ Miniature microwave and millimeter-wave radiometers for weather applications, such as the MiniRad which is onboard the Global

Environmental Monitoring System (GEMS) constellation from Orbital

○ GNSS-R instruments with real-time processing for target detection/identification [46] or—as larger downlink bandwidths are available—with raw data acquisition and on-ground processing to optimize the processing according to the target, as planned in FMPL-3, the evolution of the FMPL-2 on board

• In the field of passive VNIR/TIR hyperspectral imagers, imagers will include a larger number of bands but will include advanced image compression algorithms to minimize the amount of information to be downloaded and will incorporate artificial intelligence to download only the information extracted

Also, both their calibration will have to be refined so as to improve the quality of

Due to power and antenna size requirements, active microwave sensors (e.g., radar altimeters and SARs) will likely remain in domain of mini- and microsats (< 100 kg, e.g., ICEYE constellation [47]), and it is unlikely that active optical sensor technology (i.e., lidars) develops in small satellites in the midterm.

In the field of astronomy, and in particular heliophysics, NASA has also been taking the lead. In 2017 NASA selected nine proposals under its Heliophysics Small Explorers Program [48]: (1) the Mechanisms of Energetic Mass Ejection Explorer (MEME-X), (2) the Focusing Optics X-ray Solar Imager (FOXSI), (3) the Multi-Slit Solar Explorer (MUSE), (4) the Tandem Reconnection and Cusp Electrodynamics Reconnaissance Satellites (TRACERS), (5) the Polarimeter to Unify the Corona and Heliosphere (PUNCH), (6) the Atmospheric Waves Experiment (AWE), (7) the US Contributions to the THOR mission (THOR-US), (8) the Coronal Spectrographic Imager in the Extreme ultraviolet (COSIE), and (9) the Sun Radio Interferometer Space Experiment (SunRISE) mission concept, which is a space-based sparse array, composed of formation flying of six SmallSats designed to localize the radio emis-

sion associated with coronal mass ejections (CMEs) from the sun [49].

magnetic field structure and velocity of coronal mass ejections or CMEs.

As a final thought, quoting Prof. Puig-Suari, "Before cubesats, we were so conservative nobody was willing to try anything out of the ordinary. When we did, we discovered some of the things everybody said would not work, did work. The fundamental change was that there was a mechanism to go try to those things. Some will work and some will not, but it allows us to try them and that was very

More recently, in August 2019, NASA selected two proposals to demonstrate SmallSat technologies to study interplanetary space [50]: (1) Science-Enabling Technologies for Heliophysics (SETH) will demonstrate two technologies, an optical communications technology and experiment to detect solar energetic neutral atoms as well as an array of waves and other particles that erupt from our sun, and (2) Solar Cruiser, which will deploy a nearly 18,000 square foot solar sail and a coronagraph instrument that would enable simultaneous measurements of the sun's

**164**

This work has been supported by an ICREA Acadèmia award from the Generalitat de Catalunya to Prof. A. Camps. The author wants to express his gratitude to Profs. A. Golkar (Skoltech, Moscow, Russia) and H. Park (Universitat Politècnica de Catalunya, Barcelona, Spain) for the revision of this chapter and useful comments.

### **Author details**

Adriano Camps1,2

1 CommSensLab "María de Maeztu" Unit, Department of Signal Theory and Communications, Universitat Politècnica de Catalunya UPC-Barcelona Tech, Barcelona, Spain

2 Institut d'Estudis Espacials de Catalunya, IEEC/CTE-UPC, Barcelona, Spain

\*Address all correspondence to: camps@tsc.upc.edu

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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### *Edited by Vladislav Demyanov and Jonathan Becedas*

Being a vital modern technology, satellite systems for navigation, telecommunication, and geosciences have developed rapidly in the last 25 years. Modern satellite technologies have become a base of our civilization and support our day-to-day activity in both practice and geosciences. This book is devoted to GNSS-remote sensing for ionosphere research, modeling and mitigation techniques to diminish the ionosphere and multipath impacts on GNSS, and survey of the modern satellite missions and technologies. We hope that the experts' opinions presented in the book will be interesting for the research community and students in the area of satellites and space missions as well as in engineering and geoscience research.

Published in London, UK © 2020 IntechOpen © kettaphoto / iStock

Satellites Missions and Technologies for Geosciences

Satellites Missions and

Technologies for Geosciences

*Edited by Vladislav Demyanov and Jonathan Becedas*