Experts at the NASA Jet Propulsion Laboratory (JPL), in Pasadena, California, announce that the GALEX spacecraft has been placed on stand-by. The telescope has been investigating the Universe for nearly 9 years, even though its mission was originally supposed to last for just 2 and a half years.
Launched on April 28, 2003, the purpose of the Galaxy Evolution Explorer (GALEX) was to explore the Universe in ultraviolet wavelengths, with the goal of figuring out how the earliest stars developed in the Universe. The idea was to use this as a stepping stone for more advanced studies.
The latter included surveying the nature of dark matter and dark energy, as well as their interactions – or lack thereof – with normal matter. GALEX conducted efforts to monitor the entire night sky from a near-circular polar orbit about 697 kilometers (433 miles) above the surface.
The spacecraft was launched aboard a Pegasus XL delivery system, which was built by Orbital Sciences Corporation (OSC), in Virginia. The rocket was affixed underneath a Lockheed Martin L-1011 Stargazer aircraft.
The latter took the telescope about 60 miles (100 kilometers) east of the Cape Canaveral Air Force Station (CCAFS), in Florida, and then dropped the Pegasus XL from its grip. The rocket's engines took over, whisking GALEX to low-Earth orbit.
At this point, nine years later, the telescope is considered one of the most useful ever developed for this type of studies. Over the course of its mission, it managed to catalog literally millions of galaxies, covering up to 10 billion years. Only the earliest Universe escaped its inquisitive glance.
One of its most remarkable results is managing to confirm the nature of dark energy, after conducting a 5-year survey that covered more than 200,000 galaxies. Dark energy was once and for all determined to be a constant force, uniformly affecting the universe and propelling its runaway expansion.
JPL manages GALEX for the NASA Science Mission Directorate, at the agency's Headquarters, in Washington DC. Experts here say that the spacecraft was put on stand-by ahead of a planned decommissioning, which is scheduled to occur later this year.
“The mission's science highlights include the discovery of a gigantic comet-like tail behind a speeding star, rings of new stars around old galaxies, and 'teenager' galaxies, which help to explain how galaxies evolve,” a JPL press release reads.
“The observatory also helped confirm the existence of the mysterious substance or force known as dark energy, and even caught a black hole devouring a star,” the document concludes.