Posted: Tue, Feb 5, 2002, 10:33 PM ET (0333 GMT)
A Pegasus XL booster successfully launched NASA's High Energy Spectroscopic Imager (HESSI) spacecraft Tuesday afternoon. The Pegasus XL was deployed from its L-1011 carrier aircraft at 3:58 pm EST (2058 GMT) while flying off the coast from Cape Canaveral, Florida. The launch was delayed about 30 minutes because of temporary communications problems between the aircraft and ground control. Project officials reported later Tuesday that the spacecraft successfully reached low Earth orbit and appeared to be functioning normally. HESSI will perform x-ray and gamma-ray spectroscopy of solar flares in an effort to understand how particles are accelerated to high velocities by flares, which in turn may provide new insights into the nature of flares themselves. HESSI's launch has been delayed by more than a year to repair damage to the spacecraft caused during a ground test as well as investigations into the failure of a booster similar to the Pegasus XL. The launch was the first for the Pegasus since October 2000 and the first of up to five Pegasus flights scheduled for 2002.

Related Links:

•  Orbital press release
•  SPACE.com article
•  Spaceflight Now launch status center
•  HESSI web site