Posted: Wed, Jun 20, 2001, 9:11 AM ET (1311 GMT)
NASA announced Tuesday that it has delayed indefinitely the launch of the HESSI space science spacecraft while the investigation into the X-43A launch failure continues. NASA had tentatively planned to launch the High Energy Solar Spectroscopic Imager spacecraft on a Pegasus XL booster late this week, after having delayed the launch two weeks in the wake of the June 2 failure of the X-43A experimental aircraft and its Pegasus-derived booster. However, officials decided to delay the launch while the investigation into the X-43A failure continues. That investigation has focused on the first stage of the booster, which is derived from the first stage of the Pegasus XL. No new launch date for HESSI has been set, and may not be for some time because of a busy launch schedule at Cape Canaveral, where the HESSI launch was to have been staged from. In the meantime the Pegasus booster and its L-1011 aircraft will return to Vandenberg Air Force Base, California, so technicians can replace batteries in the booster that were reaching the end of their design life. When launched, HESSI will study the Sun at X-ray and gamma-ray wavelengths with a particular emphasis on collecting data that will allow scientists to better understand solar flares. The spacecraft was to be launched last year but was delayed when it was damaged during a vibration testing accident at JPL.

Related Links:

•  NASA KSC press release about delay
•  Spaceflight Now article