The Spitzer Space Telescope is a telescope launched into space by NASA in 2003. It is the fourth telescope in the Great Observatories program (the Hubble Space Telescope was the first). The Hubble Space Telescope takes pictures of visible light, and the Spitzer Space Telescope takes pictures of infrared light. Unlike Hubble, Spitzer orbits the Sun instead of the Earth.
The Spitzer Space Telescope is named after the scientist Lyman Spitzer. It was planned to last for 2.5 years, but it actually lasted until 2009 when it exhausted its supply of coolant. Some parts of the telescope can work even when they are warm, and are still working.