Orbital Space Plane Program

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

[1] A small, low-cost 'Assured Crew Return Vehicle' (ACRV) had been envisaged for the International Space Station, serving as an emergency evacuation capability.

[2] This evolved into the Orbital Space Plane concept: rather than being only a lifeboat, the OSP would serve as a crew transport vehicle to and from the ISS.

[citation needed] Top level requirements for the Orbital Space Plane and its related systems were approved in February 2003.

However, after a successful launch, unknown problems with the guidance system caused the vehicle to run out of thruster fuel prematurely, ending the mission before all objectives could be carried out.