Constellation Program - Legacies of Apollo and Space Shuttle

Legacies of Apollo and Space Shuttle

NASA would have used the vehicles of the Constellation Program to replace the Space Shuttle. But unlike the X-33 and other programs meant to replace the Shuttle, Constellation reused concepts already learned from the Apollo and Space Shuttle programs.

For instance, the shape of the Orion command ship closely resembled the aerodynamic shape of the Apollo Command/Service Module. However, in other respects – such as with the cockpit displays and heatshield – Orion employs new technology. The design of the launch vehicle taking Orion into orbit, the Ares I, was closely based on Apollo designs. It was based on a J-2X engine, a redesigned version of the J-2 engine used in the Saturn family of boosters.

In working on the J-2X, NASA engineers visited museums, searched for Apollo-era documentation and consulted with engineers who worked on the Apollo program. "The mechanics of landing on the moon and getting off the moon to a large extent have been solved," said Constellation program manager Jeff Hanley. "That is the legacy that Apollo gave us."

Like Apollo, Constellation would have flown a lunar orbit rendezvous mission profile, but unlike Apollo, Constellation would have also employed an Earth orbit rendezvous. The lander, known as Altair, would have been launched separately on the Ares V rocket, a rocket based on both Space Shuttle and Apollo technologies. Orion would have been launched separately and would have linked up with Altair in low earth orbit. Also unlike Apollo, Orion would have remained unmanned in lunar orbit while the entire crew landed on the lunar surface (specifically at the lunar polar regions, unlike the equatorial regions explored by Apollo). At the end of the mission, the Altair spacecraft would have launched into lunar orbit to link up with the Orion spacecraft in lunar orbit rendezvous.