One of the significant challenges in the realization of the manned international space station is the development of a crew return vehicle. This requirement, commonly known as the X-38, would serve as both an ambulance for medical emergencies and as an evacuation vehicle. To support space station schedules, the X-38 development must begin now and use a low risk approach based on proven, off-the-shelf technologies. A reduced development cost and an accelerated schedule are required to make the project attractive within current NASA budgetary constraints.
To meet these needs, the Johnson Space Center (JSC) X-38 project has been approved. The X-38 makes use of a proven lifting body shape known as the SV-5 and demonstrated parachute technology for the landing phase. The SV-5 shape without a center fin was successfully tested for re-entry during the X-23 or Prime project in the mid-1960s. The low supersonic and subsonic performance
and flying qualities were demonstrated during the X-24A (with center fin) lifting body program in the late 1960s. Because of these earlier wind tunnel and flight tests, extensive aerodynamic and heating characteristics were measured and documented. The use of parachute techniques developed by the Army for the landing phase simplifies the internal systems and eliminates the
need for a pilot. By combining the data from each of the programs and adding expertise gained from the Space Shuttle, the X-38 can merge many of the technologies needed for the X-38 missions.
The program to be conducted emphasizes an innovative "off-the-shelf" approach by using existing technologies, multi-NASA-center strengths, and alliances between NASA and other government agencies
such as the U.S. Air Force at Edwards Air Force Base and the U.S. Army at Natick and Yuma Proving Grounds. This concept allows a significant reduction in cost and schedule when compared with more traditional approaches to spacecraft development.
Both Johnson Space Center and Dryden Flight Research Center (DFRC) will contribute significantly to the program. JSC will provide both the programmatic and engineering leadership, will design and fabricate most of the vehicles and their systems, and will coordinate efforts between the various agencies. DFRC's contributions to the project will be air-launching the vehicle from the Dryden B-52, providing engineering support for flight in the lower Mach ranges, coordinating flight test ranges and facilities, and advising on state-of-the art control system technologies. The culmination of these efforts will demonstrate vehicle flight from Mach 2.0 at 80,000 feet altitude down through landing. Although the eventual spacecraft is intended to carry
four people, all phases covered under this agreement are unpiloted.
|
