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 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.
During the quiescent period crew life support would be provided by another module such as a Deep Space Habitat.
The spacecraft's life support, propulsion, thermal protection and avionics systems are designed to be upgradeable as new technologies become available.
The Orion MPCV takes basic design elements from the Apollo Command Module that took astronauts to the moon, but its technology and capability are more advanced.
It is designed to support long-duration deep space missions, with up to 21 days active crew time plus 6 months quiescent.
As a consequence, the commission recommended a significant re-allocation of goals and resources.
The Apollo-like design included a service module for life support and propulsion and 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 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.
On May 7, 2009, the Obama administration enlisted the Augustine Commission to perform a full independent review of the ongoing NASA space exploration program.