NASA Warns About Massive Satellite Re-Entry

The Upper Atmosphere Research Satellite (UARS) during deployment from Space Shuttle Discovery in September 1991 (Credits: NASA Marshall Space Flight Center).

NASA will host a media teleconference at 11 a.m. EDT on Friday, Sept. 9, to provide information about the Upper Atmosphere Research Satellite (UARS), whose reentry is expected by late September or early October. The conference will host Paul Hertz, chief scientist, NASA’s Science Mission Directorate, Washington,  Nick Johnson, chief scientist, NASA’s Orbital Debris Program, Johnson Space Center, Houston and  U.S. Air Force Maj. Michael W. Duncan, deputy chief, space situational awareness, U.S. Strategic Command, Vandenberg Air Force Base, Calif.

UARS is a 6 tons spacecraft, 10.7 long long, 4.5 m wide, launched by Space Shuttle space shuttle Discovery on Sept. 12, 1991, during STS-48. The multi-instrumented satellite has been designed to observe numerous chemical components of the atmosphere to allow better understanding of photochemistry. The satellite was decommissioned on December 14, 2005.

According to NASA officials, the spacecraft is expected to burn up during reentry, but some fragments will survive reentry and make make it to the ground. A computer simulation performed with a software program called Object Re-entry Survival Analysis Tool, or ORSAT for short, showed that the main spacecraft body along with about 150 component types will burn up during reentry, while 20 remaining components are expected to make it to the ground. The surviving mass is expected to be around half a ton, scattered over an 800 km footprint. According to NASA, the risk to public safety is minimal. The precise date of reentry is not yet known, since it will depend on solar activity and on how the spacecraft will react to atmospheric drag. The Joint Space Operations Center of U.S. Strategic Command at Vandenberg Air Force Base in California will release updates as soon as they will become available.

You can visit NASA Media website for information about the teleconference.