Owner manual

Astrophysics
Mission Description
A NASA Small Explorer (SMEX) mission, GALEX used an ultraviolet telescope to explore the origin and
evolution of galaxies and the origins of stars and heavy elements. Originally scheduled for 28 months in
duration, GALEX was recently decommissioned following ten years of extended operations.
The main objectives of the GALEX program were to:
 •MapthehistoryofstarformationintheUniverseovertheredshiftrange0<z<2(80percentofthe
ageoftheUniverse),andanswerfundamentalquestions:
(1) What is the star formation and metal production history of galaxies?
(2) When and where did the stars and elements we see today have their origins?
 •Performtherstultravioletall-skyimagingsurvey(1,000,000galaxies)
 •Performtherstultravioletwide-areaspectroscopicsurveys(100,000galaxies)
Orbital Sciences Corporation was the prime contractor for the GALEX spacecraft bus, instrument inte-
gration, and the satellite (spacecraft bus and instrument) environmental test campaign, as well as the
ground data system.
GALEXperformedtherstultraviolet
all-skysurveycoveringapproximately
1 million galaxies.
GALEXperformedtherstultraviolet
wide area spectroscopic surveys
coveringapproximately100,000
galaxies.
Mission:
NASA Small Explorer (SMEX) program
galactic astronomy
Customer:
California Institute of Technology
FACTS AT A GLANCE
GALEX spacecraft with solar arrays
stowed, in Orbital’s Dulles, Virginia satellite
manufacturing facility.
GALEX
The Galaxy Evolution Explorer
LEO