Hubble Space Telescope
Hubble orbits the Earth and should stay running until 2020. It was launched in 1990 and has since captured hundreds of iconic images including the Crab and Eagle nebulae.
Spitzer Space Telescope
Launched in 2003, Spitzer sits almost 100 million miles from Earth and viewed stars and planets in infrared. It lost most of its power in 2009 but still retains minimal functionality.
Fermi Gamma-Ray Space Telescope
Named after 20th Century physicist Enrico Fermi, it measures gamma rays emitted from black holes, neutron stars and supernovae. It was launched in 2008.
The Kepler Mission
Launched in 2009, the main purpose of this space observatory is to find Earth-like planets orbiting other stars. It orbits the Earth at a similar distance to the Spitzer.
James Webb Space Telescope
With seven times the collecting power of Hubble, the JWST will operate in a distant Earth orbit and mainly observe the infrared spectrum of distant stars after its launch in 2014.