Hubble Telescope Sent Into Orbit

Apr 25, 1990, the crew of the U.S. space shuttle Discovery places the Hubble Space Telescope, a long-term space-based observatory, into a low orbit around Earth.

The space telescope, conceived in the 1940s, designed in the 1970s, and built in the 1980s, was designed to give astronomers an unparalleled view of the solar system, the galaxy, and the universe. Initially, Hubble's operators suffered a setback when a lens aberration was discovered, but a repair mission by space-walking astronauts in December 1993 successfully fixed the problem, and Hubble began sending back its first breathtaking images of the universe.

Free of atmospheric distortions, Hubble has a resolution 10 times that of ground-based observatories. About the size of a bus, the telescope is solar-powered and orbits Earth once every 97 minutes. Among its many astronomical achievements, Hubble has been used to record a comet's collision with Jupiter, provide a direct look at the surface of Pluto, view distant galaxies, gas clouds, and black holes, and see billions of years into the universe's past.

The Hubble Space Telescope was first scheduled for launch in 1986. But due the tragic loss of the shuttle Challenger in late January of that year, the launch was delayed four years. In April 1990, the Hubble telescope was lifted into orbit aboard the shuttle Discovery.
The primary mirror of the Hubble telescope measures 2.4 m (8 ft) in diameter and weighs about 826 kg (1820 lbs). It is constructed of ultra-low expansion silica glass and coated with a thin layer of pure aluminum to reflect visible light. A thinner layer of magnesium fluoride is layered over the aluminum to prevent oxidation and to reflect ultraviolet light. The telescope measures 13.1 m (43.5 ft) in length, 4.27 m (14.0 ft) in diameter, and weighs 11,000 kg (25,500 lb).
The giant spaceborne telescope was put into orbit to collect information about a large variety of astronomical objects, from neighboring planets and stars to the most distant galaxies and quasars.