Galaxy Evolution Explorer Ready for Launch

Artistic image of the GALEX spacecraft.

NASA's next launch, the Galaxy Evolution Explorer (GALEX) mission, will lift off from Cape Canaveral, Fla. on April 28 at 8:00 a.m. Carrying into space an orbiting telescope that will observe a million galaxies across 10 billion years of cosmic history, GALEX will help astronomers determine when the stars and elements we see today had their origins.

Scientists will use data from the mission to learn when carbon, oxygen and the other chemical elements were created inside blazing stars. Most of the elements found in the human body originated in stars.

From high above the Earth the spacecraft will sweep the skies for up 28 months using state of the art ultraviolet detectors. Ultraviolet light - the type of invisible energy responsible for sunburn - is at the higher end of the electromagnetic spectrum. Looking in the ultraviolet will help astronomers single out galaxies dominated by young, hot, short live stars that give off a great deal of energy. These galaxies are actively creating stars and provide a window into the history and causes of star formation in galaxies.

The centerpiece of the satellite is a 50-centimeter (19.7 inch) telescope equipped with sensors that will gather continuous images of galaxies in the ultraviolet to study their shape, brightness and size. A device called a spectrometer will break down the light into its component colors, just as a prism separates white light into a rainbow. These measurements will enable scientists to determine the distance of galaxies. Combined with precise measurements of the ultraviolet brightness of galaxies, astronomers will determine the rate at which stars are forming within those galaxies.

The satellite will launch aboard a Pegasus XL rocket released by an L-1011 aircraft. After takeoff from the runway at Cape Canaveral Air Force Station, Fla., the plane will climb to 11,900 meters (about 39,000 feet) before releasing the Pegasus launch vehicle and GALEX. The science mission will get underway after an initial month of in-orbit checkout.

GALEX was developed under the NASA's Explorers Program, managed by the Goddard Space Flight Center. Frank Snow is the mission manager and Dr. Susan Neff is the mission scientist, both are from Goddard. Dr. Christopher Martin from the California Institute of Technology in Pasadena, Calif. is the principal investigator.

More information on the GALEX mission can be found at the following website: http://www.galex.caltech.edu/