NASA has turned off a decade-old space telescope, a year after loaning the orbiting instrument to a university that operated it with private funding.
The space agency decommissioned its Galaxy Evolution Explorer spacecraft, or GALEX, on Friday afternoon (June 28), NASA officials said. During its 10-year career, GALEX peered at hundreds of millions of galaxies, helping researchers better understand how these huge collections of stars grow and evolve.
"GALEX is a remarkable accomplishment," Jeff Hayes, NASA's GALEX program executive in Washington, D.C., said in a statement. "This small Explorer mission has mapped and studied galaxies in the ultraviolet, light we cannot see with our own eyes, across most of the sky."
The $150 million GALEX satellite launched in April 2003 on a 29-month mission to study the history of star formation in the universe.
NASA extended GALEX but eventually stopped funding it in February 2011. In May 2012, the agency made an unprecedented move, handing the spacecraft's reins over to the California Institute of Technology (Caltech) in Pasadena, which kept GALEX going with private funds.
Some of the mission's highlights include helping astronomers identify the largest known spiral galaxy in the universe, a behemoth called NGC 6872; catching a black hole in the act of gobbling up a star; and discovering a missing link in galaxy evolution, a sort of "teenage stage" between young and old.
GALEX observations also independently confirmed the nature of dark energy, the mysterious force thought to be causing the accelerating expansion of the universe, NASA officials said.
During its year in Caltech's hands, GALEX searched the sky for feeding black holes and the shock waves from long-ago star explosions, or supernovae. Among other tasks, the ultraviolet telescope also monitored how the bright, active centers of galaxies change over time.
The data GALEX gathered during its last year will keep researchers busy for some time to come, mission team members said.
"GALEX, the mission, may be over, but its science discoveries will keep on going," said Kerry Erickson, GALEX project manager at NASA's Jet Propulsion Laboratory in Pasadena.
GALEX will stay in orbit for at least 65 years, eventually falling back to Earth and burning up in our planet's atmosphere, officials said.
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