Hubble Space Telescope data, while the Goddard Space Flight Center controls the spacecraft. Space telescopes were proposed as early as 1923. Hubble was funded in the 1970s, with a proposed launch in 1983, but the project was beset by technical delays, budget problems, and the "Challenger" disaster (1986). When finally launched in 1990, Hubble's main mirror was found to have spherical aberration, compromising the telescope's capabilities. The optics were corrected to their intended quality by a servicing mission in 1993. Hubble is the only telescope designed to be serviced in space by astronauts. After launch by in 1990, five subsequent Space Shuttle missions
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.