Orbital Space Plane

The Orbital Space Plane (OSP) program was a NASA concept in the early 2000s designed to support the International Space Station requirements for crew rescue, crew transport and contingency cargo such as supplies, food and other needed equipment.

With the initiation of the Constellation program in 2004, NASA transferred the knowledge gained on the OSP to the development of Crew Exploration Vehicle, an Apollo-style capsule with separate crew and service modules.

The initial plans for the International Space Station envisaged a small, low-cost 'Assured Crew Return Vehicle' (ACRV) which would provide emergency evacuation capability; the X-38 was the prototype of this. Following cancellation of the ACRV in 2002, the program led to the more capable Orbital Space Plane concept.

The first variant of the Orbital Space Plane was designed to serve as a crew rescue vehicle for the ISS; this replaced the previous plans for a dedicated station Crew Return Vehicle, which had been sidelined by budget cuts.

This early version of the plane had been expected to enter service by 2010.

The Space Launch Initiative program began with the award of reusable launch vehicle study contracts in 2000. In November 2002 it was evolved into the Orbital Space Plane Program and the Next Generation Launch Technology Program.

Future versions of the Orbital Space Plane would have been launched on an existing EELV rocket to carry crews to the International Space Station. It was envisaged that the OSP would operate alongside the Space Shuttle with the OSP responsible for crew flights and the shuttle handling construction and cargo flights. At the time, the shuttle program was not yet set for retirement and was thought to be technically viable up until the 2030s. Thus it was expected that the two spacecraft would complement each other throughout the lifespan of the ISS. One advantage of this approach would have been assured manned access to space; the lack of this capability was to be highlighted starkly with the loss of Space Shuttle Columbia.

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