**3. Present developments**

To date there are only two servicing HVs, namely, the X-37 and the Soyuz spacecrafts. As discussed before, the former is a US unmanned reentry spacecraft (winged-body) close to the Space Shuttle, while the latter is the only human-rated capsule operated by Russian Federation [9, 27, 28].

The X-37's aerodynamic design was derived from the Shuttle Orbiter, and hence the X-37 has a similar lift-to-drag ratio (L/D). The X-37 is the smallest and lightest lifting winged vehicle flown to date. It features a forwarded double delta wing and a butterfly tail [9]. The X-37 re-enters Earth's atmosphere and lands automatically. It is the second reusable spacecraft to have such a capability, after the Buran shuttle [14]. The X-37 is now operated by the USAF being transferred to the Defense Advanced Research Projects Agency (DARPA).

The Soyuz spacecraft was designed for the Soviet space program by the Korolev Design Bureau in the 1960s, and it is still in service today. It is currently the only manned space vehicle in the world to support flight to and from the ISS. The spacecraft consists of three parts, namely, orbital module (OM), service module (SM), and reentry module (RM). The OM is a spheroid spacecraft's segment which provides accommodation for the crew during mission. The cylindrical spacecraft's segment is the SM. It features solar panels attached and contains the instruments and engines. Finally, the RM is a small capsule which returns the crew to Earth [27, 28].

**7**

*Introductory Chapter: Hypersonic Vehicles - Past, Present, and Future Insights*

As future developments in HVs, there are Dream Chaser and Space RIDER (both lifting bodies) concepts. They are being developed by the USA and Europe, respec-

The Dream Chaser is a reusable lifting-body spaceplane that can fly autonomously to resupply the ISS with both pressurized and unpressurized cargos. The vehicle is designed to be launched on expendable rockets, return from space by gliding, and autonomously land on conventional runways. The potential further development of the spaceplane includes a human-rated version which would be capable of carrying up from two to seven people to and from LEO. Dream Chaser design is derived from NASA HL-20 lifting body which was itself like the Soviet

The experience and data obtained by Europe so far on Hermes, FESTIP, and FLPP programs served as stepping stones toward a vehicle called Space Reusable Integrated Demonstrator for Europe Return (Space RIDER), underdeveloped by ESA [29]. The Italian Space Agency (ASI), with the project being led by the Italian Aerospace Research Centre (CIRA), presented its own Programme for Reusable In-orbit Demonstrator in Europe (PRIDE) to develop the prototype named Space RIDER [30]. It is an unmanned spacecraft aiming to provide the ESA with afford-

Such a limited number of operating HVs are due to the high operative cost and, especially, to the complexity in designing such vehicles, especially for human-rated missions. Indeed, HVs' design is an extremely challenging process involving several disciplines, e.g., aerodynamic, aerothermodynamic, control, avionics navigation systems, propulsion, and structure. As well known, these disciplines are strongly coupled with one another and generally influence each other because they involve antagonistic objectives. Therefore, it is expected that synergistic interactions, between vehicle subsystems and functions, can produce an optimized multidisciplinary vehicle design with significant performance and

This suggests using specific methodologies to assess trade-off analyses between the enabling disciplines as the only way to obtain a satisfactory (global optimal) vehicle design, referred to as multidisciplinary design optimization

The book aims at highlighting that the design of HVs must pass from a conventional design to a more complex and challenging highly integrated design frame-

Several chapters in the present book focused attention on this fundamental topic, especially for what concerns the design of scramjet-propelled vehicle configurations. For instance, the design and optimization about the integration of airframe-propulsion design issue are discussed as well as the design of vehicle TPS with parametric integral soft object-based procedure. Anyway, investigations of more conventional topics are also provided in the book, as numerical simulations of

In this framework, the ambition of the present book is to support industries, research centers, and space agencies in their own design and development of next-generation HVs. Therefore, this book is recommended for both students and research engineers involved in all design phases, typical for hypersonic vehicles.

**5. Designing hypersonic vehicles and preset book aims**

*DOI: http://dx.doi.org/10.5772/intechopen.87988*

**4. Future developments**

tively [13, 29, 30].

BOR-4 [1, 14, 31].

able and routine access to space.

economic improvements [32–40].

work, according to the MDO approach.

base pressure and drag of typical reentry vehicles.

(MDO) [41–48].
