*4.3.2.3 Radiation detectors*

Several instruments are onboard the rover dedicated to the following: the characterization of high-energy particles on the surface with the Radiation Assessment Detector (RAD), critical to determine the risks for a potential manned mission; and the detection of subsurface water molecules by the Dynamic Albedo of Neutrons (DAN) instrument, which has astrobiological implications, but also serves to study the potential use of *in situ* water by future missions.

#### *4.3.2.4 Environmental sensors*

The meteorological station onboard the MSL is called Rover Environmental Monitoring Station (REMS) monitors temperature, pressure, winds, UV radiation, humidity, etc. The data gathered by REMS are used to characterize and model the Martian climate along the seasons and years, which are key not only to understand the Martian weather, but also for the planning of future manned missions.

### *4.3.3 Where has curiosity led Curiosity? The science discoveries*

The Curiosity rover has been working nonstop since its arrival to Mars in 2012, and it will continue to do so for the time being, as it is still in good shape. Probably the Mars 2020 rover, Perseverance, will arrive to Mars in 2021, while Curiosity is still fully operative. Given the scientific feedback already provided by this rover, it can be considered as a new great success by NASA, but it will for sure still bring interesting new discoveries during the remainder of the mission. Some of the MSL findings have confirmed or supported the knowledge gained by MER, but others have pushed the Martian understanding some steps further.

### *4.3.3.1 The water: sustained water currents, and fresh water and thick atmosphere*

The Curiosity rover identified boulders that likely were rounded by the effect of water currents in Mount Sharp, in what was probably a river/lake system where water flowed for around one million years [35]. Also, the SAM instrument isotopic analysis on the Martian atmosphere elements indicates that the planet has come to be deprived of its early thicker atmosphere and water masses by, among other things, the effects of the solar winds in a planet without a magnetosphere [36–38].

#### *4.3.3.2 A habitable environment*

The analysis of the Martian chemistry of mudstones in the Yellowknife Bay confirmed the presence of key elements needed for life, such as oxygen, phosphorus, sulfur, and nitrogen. Also, the presence of fresh water can be inferred from the lack of many salts and the presence of clay minerals [39].

#### *4.3.3.3 Organic carbon*

One of the most important discoveries performed by the SAM instrument is based on the analyses from drilled samples (at some centimeters depth) in Mount Sharp. These analyses confirmed the presence of organic molecules. This is a very important discovery considering that any form of life would be formed from organic compounds. Also, it shows that preservation (and detection) of these molecules is possible, even at a few centimeters below the surface (where the UV-radiation degrades and breaks the long molecular chains of the organics) [40].

#### *4.3.3.4 The methane cycle on Mars*

The presence of methane on Mars is puzzling the scientific community, as it varies in concentration with time, meaning that there is an existing methane cycle on the planet. The formation of methane can occur from chemical reactions, but also by living organisms. Curiosity has monitored the Martian methane with SAM's Tunable Laser Spectrometer, observing variations up to one order of magnitude in a period of only 2 months. Its source, however, is still to be identified [41].

**103**

*Evolution of the Scientific Instrumentation for* In Situ *Mars Exploration*

The RAD instrument has performed analysis during the whole duration of the mission, including cruise. The results show that the radiation dose during a Mars mission would pose a risk for the human crew. The Galactic Cosmic Rays and the Solar Energetic Particles are the main radiation sources that will affect potential future astronauts on the surface of Mars. The radiation characterization performed by Curiosity during the mission will help defining safe mission concepts for the

The Martian missions after MSL have been orbiters centered in the study of the Martian atmosphere. Mars Atmosphere and Volatile Evolution (MAVEN) and the Indian Mars Orbiter Mission (Mangalyaan) were launched in 2013 and have been studying the evolution of the higher layers of the atmosphere in order to understand its loss. MAVEN has confirmed how the solar wind, in absence of a protective magnetic field, facilitates the escape of the charged particles on the Martian atmosphere [44]. Later in 2016, the first part of the ExoMars mission deployed the Trace Gas Orbiter (TGO) in the Martian orbit, incorporating a suite of instruments (ACS and NOMAD) to analyze the concentration of methane and other gases with detection limits as low as 10 parts per thousand, with the ultimate objective of helping

Finally, 2018 saw the launch of another NASA lander, using the same platform concept as for the Phoenix mission some years before. This mission was named Interior Exploration using Seismic Investigation, Geodesy and Heat Transport (InSight) and was devoted to the analysis of the planet interior, performing seismologic and in-depth thermal analysis. The data gathered by this mission will help understand the formation

The decade of the 2020s opens a *golden age* of the *in situ* Martian exploration. During the summer of 2020, two missions of great impact will be launched to Mars. On the one hand, the improved (1 Ton heavy) version of MSL, the Perseverance rover, will be deployed by NASA on the Jezero crater in Mars. On the other hand, China will launch the ambitious Tianwen-1, which will try to place, in only one mission, an orbiter, a lander and a mid-size rover (240 kg). In the following launch window in 2022, Europe (ESA) and Russia (Roscosmos) will join the exploration of Mars with the second phase of the ExoMars mission, which will deploy the Rosalind Franklin rover (named in honor of the British scientific) on Oxia Planum by the beginning of 2023.

The upcoming NASA mission to Mars with the Perseverance rover breaks frontiers in many scientific and technological aspects, also giving clear steps as defined by the Mars Exploration Program. Perseverance is in many aspects similar to Curiosity, but it implements several improvements and novel analytical techniques. On the one hand, Raman spectroscopy, a powerful analytical technique for molecular identification of samples, unprecedented in planetary exploration missions, appears in the payload of the rover not one, but twice. The SuperCam multianalytical instrument suite includes a remote Raman spectrometer that will analyze rocks and soils at distances of up to 12 m. Also, the SHERLOC instrument placed in the arm of the rover will use an UV laser source to perform Raman spectroscopy

*DOI: http://dx.doi.org/10.5772/intechopen.93377*

manned exploration of Mars [42–43].

understand the methane cycle in Mars.

process of the planet compared to others in the Solar System.

**5. What's next? The future of Martian exploration**

**5.1 Flying high: the perseverance breakthroughs**

optimized for the detection of organics.

*4.3.3.5 Radiation*

*Evolution of the Scientific Instrumentation for* In Situ *Mars Exploration DOI: http://dx.doi.org/10.5772/intechopen.93377*

#### *4.3.3.5 Radiation*

*Mars Exploration - A Step Forward*

*4.3.2.4 Environmental sensors*

*4.3.3.2 A habitable environment*

*4.3.3.4 The methane cycle on Mars*

*4.3.3.3 Organic carbon*

The meteorological station onboard the MSL is called Rover Environmental Monitoring Station (REMS) monitors temperature, pressure, winds, UV radiation, humidity, etc. The data gathered by REMS are used to characterize and model the Martian climate along the seasons and years, which are key not only to understand

The Curiosity rover has been working nonstop since its arrival to Mars in 2012, and it will continue to do so for the time being, as it is still in good shape. Probably the Mars 2020 rover, Perseverance, will arrive to Mars in 2021, while Curiosity is still fully operative. Given the scientific feedback already provided by this rover, it can be considered as a new great success by NASA, but it will for sure still bring interesting new discoveries during the remainder of the mission. Some of the MSL findings have confirmed or supported the knowledge gained by MER, but others

the Martian weather, but also for the planning of future manned missions.

*4.3.3.1 The water: sustained water currents, and fresh water and thick atmosphere*

The Curiosity rover identified boulders that likely were rounded by the effect of water currents in Mount Sharp, in what was probably a river/lake system where water flowed for around one million years [35]. Also, the SAM instrument isotopic analysis on the Martian atmosphere elements indicates that the planet has come to be deprived of its early thicker atmosphere and water masses by, among other things, the effects of the solar winds in a planet without a magnetosphere [36–38].

The analysis of the Martian chemistry of mudstones in the Yellowknife Bay confirmed the presence of key elements needed for life, such as oxygen, phosphorus, sulfur, and nitrogen. Also, the presence of fresh water can be inferred from the lack

One of the most important discoveries performed by the SAM instrument is based on the analyses from drilled samples (at some centimeters depth) in Mount Sharp. These analyses confirmed the presence of organic molecules. This is a very important discovery considering that any form of life would be formed from organic compounds. Also, it shows that preservation (and detection) of these molecules is possible, even at a few centimeters below the surface (where the UV-radiation degrades and breaks the long molecular chains of the organics) [40].

The presence of methane on Mars is puzzling the scientific community, as it varies in concentration with time, meaning that there is an existing methane cycle on the planet. The formation of methane can occur from chemical reactions, but also by living organisms. Curiosity has monitored the Martian methane with SAM's Tunable Laser Spectrometer, observing variations up to one order of magnitude in a

period of only 2 months. Its source, however, is still to be identified [41].

*4.3.3 Where has curiosity led Curiosity? The science discoveries*

have pushed the Martian understanding some steps further.

of many salts and the presence of clay minerals [39].

**102**

The RAD instrument has performed analysis during the whole duration of the mission, including cruise. The results show that the radiation dose during a Mars mission would pose a risk for the human crew. The Galactic Cosmic Rays and the Solar Energetic Particles are the main radiation sources that will affect potential future astronauts on the surface of Mars. The radiation characterization performed by Curiosity during the mission will help defining safe mission concepts for the manned exploration of Mars [42–43].

The Martian missions after MSL have been orbiters centered in the study of the Martian atmosphere. Mars Atmosphere and Volatile Evolution (MAVEN) and the Indian Mars Orbiter Mission (Mangalyaan) were launched in 2013 and have been studying the evolution of the higher layers of the atmosphere in order to understand its loss. MAVEN has confirmed how the solar wind, in absence of a protective magnetic field, facilitates the escape of the charged particles on the Martian atmosphere [44]. Later in 2016, the first part of the ExoMars mission deployed the Trace Gas Orbiter (TGO) in the Martian orbit, incorporating a suite of instruments (ACS and NOMAD) to analyze the concentration of methane and other gases with detection limits as low as 10 parts per thousand, with the ultimate objective of helping understand the methane cycle in Mars.

Finally, 2018 saw the launch of another NASA lander, using the same platform concept as for the Phoenix mission some years before. This mission was named Interior Exploration using Seismic Investigation, Geodesy and Heat Transport (InSight) and was devoted to the analysis of the planet interior, performing seismologic and in-depth thermal analysis. The data gathered by this mission will help understand the formation process of the planet compared to others in the Solar System.
