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 Surveillance Telescope Space Surveillance Telescope The Space Surveillance Telescope is a telescope for detecting and tracking orbital debris. It has a 3.5 meter (138″) aperture mirror and came online in 2011. Two noted design features include Mersenne-Schmidt type optics and a curved CCD. In 2010s the telescope, which was in New Mexico, United States, was transferred to United States Air Force Space Command and moved to Australia. The discovery and tracking of space debris is noted as a growing problem in the 21st century. One problem is that among the 20-30 thousand large objects in orbit that are tracked, and an estimated