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Explorer: GALEX (SMEX 7)


GALEX (Galaxy Evolution Explorer) uses a Modified Ritchey-Chretien (Aspheric corrected) telescope for UV imaging and spectroscopic survey to map the global history and probe the causes of star formation and its evolution over the redshift range 0<z<2.

The GALEX method exploits demonstrated techniques to

  • use the Lyman break to measure redshift and distance in photometric and spectroscopic data
  • UV slope to measure extinction
  • UV luminosity to measure star formation rate and its history over cosmic time

The GALEX space craft is based on Orbital's LEOStar-2 bus.

GALEX was decommissioned on 28 June 2013 after more than 10 years of operation.

Nation: USA
Type / Application: Astronomy, UV
Operator: NASA
Contractors: Orbital Sciences Corporation (OSC)
Equipment: 50 cm Modified Ritchey-Chretien Telescope
Configuration: LEOStar-2
Propulsion: ?
Power: Deployable fixed solar array, batteries
Mass: 312 kg
Orbit: 690 km × 702 km, 29
Satellite COSPAR Date LS Launch Vehicle Remarks
GALEX (SMEX 7, Explorer 83) 2003-017A 28.04.2003 CC, L-1011, RW13/31 Pegasus-XL


  • NSSDC Master Catalog: GALEX
  • Orbital Sciences Corp.: GALEX