What is Great Observatories program?
[[File:Great Observatories.jpg|thumb|250px|Four '''Great Observatories''']] The '''Great Observatories''' program is four large, powerful space-based [[telescope]]s. They are a series of [[satellite]]s placed by [[NASA]]. Each [[Space observatory]] has been important to [[astronomy]]. * The [[Hubble Space Telescope]] (HST) looks at [[optical spectrum|visible light]] and [[Near ultraviolet|near-ultraviolet]]. It was launched in 1990. In 1997 ability to look at the [[Near infrared|near-infrared]] range was added. In 2009 there was a mission to service Hubble. * The [[Compton Gamma Ray Observatory]] (CGRO) looks at [[gamma ray]]s. It also looks at some [[hard x-ray]]s as well. It was launched in 1991. It was deorbited in 2000. * The [[Chandra X-ray Observatory]] (CXO) looks at [[soft x-ray]]s. It was launched in 1999. * The [[Spitzer Space Telescope]] (SST) looks at the [[infrared]] spectrum. It was launched in 2003. [[Category:Telescopes]] {{sci-stub}} [[Category:Astronomical observatories]]