The X-38 was an experimental re-entry vehicle designed by NASA to research a possible emergency crew return vehicle (CRV) for the International Space Station (ISS). The 1995–2002 program also developed concepts for a crew return vehicle design that could be modified for other uses, such as a possible joint U.S. and international human spacecraft that could be launched on the French Ariane 5 booster. The program would eventually develop a total of three test prototype flight demonstrators for the proposed Crew Return Vehicle, each having incremental improvements on its predecessor. All three were wingless lifting body vehicles used in drop tests. The X-38 program was canceled in 2002 due to budget cuts. History The maximum crew size for the ISS is dependent on crew rescue capacity. Since it is imperative that the crew members be able to return to Earth in case of an unexpected emergency, a Crew Return Vehicle able to hold up to seven crew members was initially planned by the ISS program leadership. This would have allowed the full complement of seven astronauts to live and work on the ISS. During the early years of ISS on-orbit construction, the crew was limited to three, corresponding to a single Russian Soyuz TMA vehicle that could be docked to the station at any given time. Later in May 2009 provisions were added for a total of two docked Soyuz vehicles simultaneously and the ISS crew was increased to 6 members. NASA has designed several crew return vehicles over the years with varying levels of detail. A small, in-house development study of the X-38 concept first began at Johnson Space Center (JSC) in early 1995, however several types of emergency scenarios were recognized by NASA as early as 1992 that drove the need for crew return from the International Space Station: 1. A serious illness or injury to a station astronaut 2. A fire or collision with space debris 3. Grounding of the space shuttle so that it could not deliver life-sustaining supplies. In early 1996, a contract was awarded to Scaled Composites, Inc., of Mojave, Calif., for the construction of three full-scale atmospheric test airframes. The first vehicle airframe was delivered to JSC in September 1996. Development In an unusual move for an X-plane, the program involved the European Space Agency and the German Space Agency DLR. It was originally called X-35. The program manager was John Muratore, while