 Apollo 1 did not launch and its crew died in a ground-based capsule fire, and Apollo 7 and Apollo 9 were low Earth orbit missions testing spacecraft components and docking maneuvers.Nine astronauts later flew unused Apollo command modules in the Apollo Applications Program's Skylab and Apollo–Soyuz Test Project.Of the 24 astronauts who flew to the Moon, two went on to command a Skylab mission, one commanded Apollo–Soyuz, one flew as commander for Approach and Landing Tests of the Space Shuttle, and two commanded orbital Space Shuttle missions.