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
Space Shuttle in accidents. It was used for orbital space missions by NASA, the U.S. Department of Defense, the European Space Agency, Japan, and Germany. The United States funded Shuttle development and operations except for the Spacelab modules used on D1 and D2sponsored by Germany. SL-J was partially funded by Japan. At launch, it consisted of the "stack", including the dark orange external tank (ET) (for the first two launches the tank was painted white); two white, slender solid rocket boosters (SRBs); and the Orbiter Vehicle, which contained the crew and payload. Some payloads were launched into higher orbits with either of