Space Shuttle program March 25, 1979, and was first launched on April 12, 1981—the 20th anniversary of Yuri Gagarin's space flight—with a crew of two. "Challenger" (OV-099) was delivered to KSC in July 1982, "Discovery" (OV-103) in November 1983, "Atlantis" (OV-104) in April 1985 and "Endeavour" in May 1991. "Challenger" was originally built and used as a Structural Test Article (STA-099), but was converted to a complete orbiter when this was found to be less expensive than converting "Enterprise" from its Approach and Landing Test configuration into a spaceworthy vehicle. On April 24, 1990, "Discovery" carried the Hubble Space Telescope into space during
Rendezvous: A Space Shuttle Simulation Rendezvous: A Space Shuttle Simulation Rendezvous: A Space Shuttle Simulation, is a space simulator published 1982 by Edu-Ware, and developed by Titan Computer Products and NASA scientist Wesley Huntress. Accompanied by a thick "Spacecraft Operations" manual with a chapter on use in the classroom, this flight simulator was marketed as being as educational as it was fun to play. The simulation is centered on a typical Space Shuttle mission to service a space station. Mission phases include "Earth Lift-Off", "Orbital Rendezvous", "Approach" and "Alignment and Docking". It was released for the Apple II in 1982 with positive feedback from reviewers.