Marshall Space Flight Center of the launch vehicle. Finally, on April 24, 1990, on Mission STS-31, Shuttle "Discovery" launched the Hubble telescope successfully into its planned orbit. Almost immediately it was realized that the optical performance was not as expected; analysis of the flawed images showed that the primary mirror had been ground to the wrong shape, resulting in spherical aberration. Fortunately, the Hubble telescope had been designed to allow in-space maintenance, and in December 1993, mission STS-61 carried astronauts to the Hubble to make corrections and change some components. A second repair mission, STS-82, was made in February 1997, and a third, STS-103,
Space telescope Space telescope A space telescope or space observatory is an instrument located in outer space to observe distant planets, galaxies and other astronomical objects. Space telescopes avoid many of the problems of ground-based observatories, such as light pollution and distortion of electromagnetic radiation (scintillation). In addition, ultraviolet frequencies, X-rays and gamma rays are blocked by the Earth's atmosphere, so they can only be observed from space. Theorized by Lyman Spitzer in 1946, the first operational space telescopes were the American Orbiting Astronomical Observatory OAO-2 launched in 1968 and the Soviet Orion 1 ultraviolet telescope aboard space station Salyut 1 in