Orion Crew Exploration Vehicle (CEV)
Orion CEV design as of 2009.
On January 14, 2004, U.S. President George W. Bush announced the Crew Exploration Vehicle (CEV) as part of the Vision for Space Exploration. The CEV was partly a reaction to the Space Shuttle Columbia accident, the subsequent findings and report by the Columbia Accident Investigation Board (CAIB), and the White House's review of the American space program. The CEV effectively replaced the conceptual Orbital Space Plane (OSP), which was proposed after the cancellation of the Lockheed Martin X-33 program to produce a replacement for the space shuttle. As the Vision for Space Exploration was developed into the Constellation program under NASA administrator Sean O'Keefe, the Crew Exploration Vehicle was renamed the Orion Crew Exploration Vehicle, after the stellar constellation of the same name.
Constellation proposed using the Orion CEV in both crew and cargo variants to support the International Space Station and as a crew vehicle for a return to the Moon. The Apollo-like design included a service module for life support and propulsion and the crew/command module was originally intended to land on solid ground on the US west coast using airbags, but later changed to ocean splashdown. The Orion CEV weighs about 23 tonnes, less than the 30 tonne Apollo command/service module. The crew module would weigh about 8.9 tonnes, greater than the equivalent Apollo command module at 5.8 tonnes. With a diameter of 5 metres as opposed to 3.9 metres, the Orion CEV would provide 2.5 times greater volume as compared to the Apollo CM. The service module was originally planned to use liquid methane (LCH4) as its fuel, but switched to hypergolic propellants due to the infancy of oxygen/methane-powered rocket technologies and the goal of launching the Orion CEV by 2012.
The Orion CEV design consisted of two main parts: a conical crew module (CM) and a cylindrical service module (SM) holding the spacecraft's propulsion system and expendable supplies. Both were based substantially on the Apollo command and service modules (Apollo CSM) flown between 1967 and 1975.
The Orion CEV was to be launched on the Ares I rocket to low Earth orbit, where it would rendezvous with the Altair lunar surface access module (LSAM) launched on a heavy-lift Ares V launch vehicle for lunar missions.
Cancellation of Constellation program
Artist's conception of the Orion spacecraft as then designed in lunar orbit.
On May 7, 2009, the Obama administration enlisted the Augustine Commission to perform a full independent review of the ongoing NASA space exploration program. The commission found the then current Constellation Program to be woefully under-budgeted, behind schedule by four years or more in several essential components, with significant cost overruns, and unlikely to be capable of meeting any of its scheduled goals under its current budget. As a consequence, the commission recommended a significant re-allocation of goals and resources. As one of the many outcomes based on these recommendations, on October 11, 2010, the Constellation program was cancelled, ending development of the Altair, Ares I, and Ares V. The Orion Crew Exploration Vehicle survived the cancellation and was renamed the Multi-Purpose Crew Vehicle (MPCV), to be launched on the Space Launch System.
Orion Multi-Purpose Crew Vehicle (MPCV)
Through the program restructuring from Constellation to Post Constellation, the Orion development program moved from the development of three different versions of the Orion capsule, each for a different task, to the development of a single version capable of performing multiple tasks. On October 30, 2014, the somewhat redesigned Multi-Purpose spacecraft completed its first Flight Readiness Review (FRR), allowing the vehicle to be integrated with the Delta IV rocket and readied for launch. On December 5, 2014 it was successfully launched into space and retrieved at sea after splashdown on the Exploration Flight Test 1 (EFT-1), marking NASA's re-entry into the business of designing and producing new crewed spacecraft.