The launch of NASA's Galaxy Evolution Explorer (GALEX) spacecraft aboard an Orbital Sciences Corporation (OSC) air-launched Pegasus vehicle is scheduled for deployment over the Atlantic Ocean from OSC's L-1011 carrier aircraft on Monday, April 28 at 8 a.m. EDT. This time is contained within a launch window that opens at 7:50 a.m. and closes at 9:50 a.m. EDT. 

The launch begins with the drop of the Pegasus rocket from the L-1011 over the Atlantic Ocean at an altitude of 39,000 feet at a location approximately 100 nautical miles offshore east-northeast of Cape Canaveral. The launch is expected to be visible from the coast. Spacecraft separation from the Pegasus occurs 11 minutes later. At that time the satellite will be in a circular orbit of 431 statute miles (690 km) at a 29-degree inclination.

GALEX will observe a million galaxies across 10 billion years of cosmic history to help astronomers determine when the stars and galaxies we see today had their origins. During the course of its two-year investigation, GALEX will conduct the first ultraviolet surveys of the entire extragalactic sky, including the first wide-area spectroscopic surveys. This vast data archive will form a lasting legacy. Rich in objects from galaxies to quasars to white dwarf stars, it will serve as a resource for the entire astronomical community. 

The Jet Propulsion Laboratory (JPL) is responsible for the project management of GALEX and built the telescopic instrument. Orbital Sciences Corporation built the spacecraft bus and is responsible for instrument integration. The California Institute of Technology is responsible for the science operations and astronomical data. The Kennedy Space Center is responsible for spacecraft/launch vehicle integration, countdown management, launch vehicle engineering oversight and mission assurance.

FMI: www.nasa.gov; www.galex.caltech.edu