Upper Atmosphere Research Satellite. Credit: NASA

A hefty NASA satellite is nearing a nose-dive to Earth – almost six years after the end of a productive scientific life.

The Upper Atmosphere Research Satellite — or UARS — is expected to re-enter Earth’s atmosphere in late September or early October 2011.

The 35-foot-long, 15-foot-diameter UARS was decommissioned on Dec. 14, 2005.

The satellite was launched in 1991 by the Space Shuttle Discovery. UARS weighs roughly six and a half tons, or 13,000 pounds.

NASA will be taking measures to inform the public about the pieces of the satellite that are expected to survive reentry.

“The risk to public safety or property is extremely small, and safety is NASA’s top priority. Since the beginning of the Space Age in the late-1950s, there have been no confirmed reports of an injury resulting from re-entering space objects. Nor is there a record of significant property damage resulting from a satellite re-entry,” noted NASA today.

It is too early to say exactly when UARS will re-enter and what geographic area may be affected, but NASA is watching the satellite closely and will keep you informed.

NASA will post updates weekly until four days before the anticipated re-entry, then daily until about 24 hours before re-entry, and then at about 12 hours, six hours and two hours before re-entry.

The updates will come from the Joint Space Operations Center of U.S. Strategic Command at Vandenberg Air Force Base, Calif., which works around the clock detecting, identifying and tracking all man-made objects in Earth orbit, including space junk.

The actual date of re-entry is difficult to predict because it depends on solar flux and the spacecraft’s orientation as its orbit decays.

As re-entry draws closer, predictions on the date will become more reliable.

Lastly, NASA officials say that if you find something you think may be a piece of UARS, do not touch it. Contact a local law enforcement official for assistance.

By Leonard David