THUNDER BAY – Over the next week, a space satellite will drop out of orbit and return to earth. NASA reports, “The Upper Atmosphere Research Satellite, or UARS, is expected to re-enter Earth’s atmosphere in late September or early October 2011, almost six years after the end of a productive scientific life. Although the spacecraft will break into pieces during re-entry, not all of it will burn up in the atmosphere”.
The latest update from NASA states, “The orbit of UARS was 140 mi by 155 mi (225 km by 250 km). Re-entry is expected Sept. 23, plus or minus a day. The re-entry of UARS is advancing because of a sharp increase in solar activity since the beginning of this week”.
The space agency adds, “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”.
The satellite was launched in 1991 by the Space Shuttle Discovery. It is 35 feet long, 15 feet in diameter, weighs 13,000 pounds, and carries 10 instruments. UARS orbited at an altitude of 375 miles with an orbital inclination of 57 degrees.
Designed to operate for three years, six of its ten instruments are still functioning. UARS measures ozone and chemical compounds found in the ozone layer which affect ozone chemistry and processes. UARS also measures winds and temperatures in the stratosphere as well as the energy input from the Sun. Together, these help define the role of the upper atmosphere in climate and climate variability.
It is too early to say exactly when UARS will re-enter and what geographic area may be affected.