Notable satellite observatories

name nationality years in

service discoveries/

notable features

Radio (wavelengths less than 0.1 cm)

Cosmic Background Explorer (COBE) (Cosmic Background Explorer) U.S. 1989–93 mapped cosmic microwave background from the big bang

VLBI Space Observatory Programme (VSOP) Japan 1997–2005 joined with radio telescopes (telescope) on Earth to form an array 33,000 km across

Infrared (wavelengths between 0.1 cm and 7 × 10⁻⁵ cm)

Infrared Astronomical Satellite (IRAS) (Infrared Astronomical Satellite) U.S./U.K./

Netherlands 1983 first space observatory to map the entire sky at infrared wavelengths

Spitzer Space Telescope U.S. 2003– studied atmospheres of extrasolar planets (extrasolar planet)

Optical (wavelengths between 4 × 10⁻⁵ and 7 × 10⁻⁵ cm)

Hipparcos ESA* 1989–93 measured the distances to more than 100,000 stars (star)

Hubble Space Telescope (HST) (Hubble Space Telescope) U.S./ESA 1990– accurately determined the rate of the universe's expansion

Ultraviolet (wavelengths between 4 × 10⁻⁵ and 10⁻⁸ cm)

International Ultraviolet Explorer (IUE) (International Ultraviolet Explorer) U.S./U.K./ESA 1978–96 observed light ring around Supernova 1987A

Solar and Heliospheric Observatory (SOHO) (Solar and Heliospheric Observatory) U.S./ESA 1995– studied sunspots (sunspot) on the far side of the Sun

X-ray (wavelengths between 10⁻⁸ and 10⁻¹¹ cm)

Röntgensatellit (ROSAT) Germany 1990–99 surveyed the entire sky

Chandra X-ray Observatory U.S. 1999– found direct proof of the existence of dark matter

Gamma-ray (wavelengths less than 10⁻¹¹ cm)

Compton Gamma Ray Observatory (CGRO) (Compton Gamma Ray Observatory) U.S. 1991–99 showed that gamma-ray bursts (gamma-ray burster) happened outside the Milky Way

Swift U.S. 2004– studied hundreds of gamma-ray bursts

* European Space Agency