Sunday, January 27, 2008

An unresponsive United States reconnaissance satellite is in an uncontrolled, decaying orbit and will re-enter Earth‘s atmosphere in late February or early March.

According to Gordon Johndroe, a spokesman for the U.S. National Security Council, “Appropriate government agencies are monitoring the situation.”

The satellite is out-of-control, and therefore there is no possibility to guide it to re-entry over an ocean or unpopulated area. On the one hand, since most of the earth’s surface is water or unpopulated, death or property loss due to any falling fragments, which may result from the satellite entering the atmosphere, is statistically unlikely. On the other hand, it cannot be ruled out entirely. According to General Gene Renuart, of the United States Air Force, there is a chance that the satellite may re-enter over North America. After entering the atmosphere, some debris could possibly fall on land.

“Numerous satellites over the years have come out of orbit and fallen harmlessly. We are looking at potential options to mitigate any possible damage this satellite may cause,” said Johndroe.

Concerns have also been raised that some materials used in the satellite’s construction could be hazardous if they reach the ground. The satellite contains quantities of toxic hydrazine fuel, which is used for maneuvering, although this is likely to burn up on re-entry. Some of the optics aboard the satellite may contain beryllium, which is also toxic.

As the satellite was part of a classified U.S. military program, no other details, including its name, have been made public. The satellite is publicly identified by the codenames USA-193 and NRO L-21. It was launched in December 2006, by a Delta II rocket from Vandenberg Air Force Base. Ground controllers lost contact with the satellite shortly after it reached orbit. Amateur observers had been tracking USA-193 for some time, and believed that its orbit was decaying.