NASA's Upper Atmosphere Research Satellite reenters Earth's atmosphere
The precise reentry time and location of debris impacts have not been determined.
September 26, 2011
NASA's decommissioned Upper Atmosphere Research Satellite (UARS) fell back to Earth between 11:23 p.m. EDT September 23 and 1:09 a.m. September 24, 20 years and 9 days after its launch on a 14-year mission that produced some of the first long-term records of chemicals in the atmosphere.
NASA's decommissioned Upper Atmosphere Research Satellite fell back to Earth between 11:23 p.m. EDT September 23 and 1:09 a.m. September 24. NASA
The precise reentry time and location of debris impacts have not been determined. During the reentry period, the satellite passed from the east coast of Africa over the Indian Ocean, then the Pacific Ocean, then across northern Canada, then across the northern Atlantic Ocean, to a point over West Africa. The vast majority of the orbital transit was over water, with some flight over northern Canada and West Africa.
Six years after the end of its productive scientific life, UARS broke into pieces during reentry, and most of it up burned in the atmosphere. Data indicates the satellite likely broke apart and landed in the Pacific Ocean far off the U.S. coast. Twenty-six satellite components, weighing a total of about 1,200 pounds (550 kilograms), could have survived the fiery reentry and reached the surface of Earth. However, NASA is not aware of any reports of injury or property damage.
The Operations Center for the Joint Functional Component Command (JFCC-Space) at Vandenberg Air Force Base, California, which works around the clock detecting, identifying, and tracking all man-made objects in Earth orbit, tracked the movements of UARS through the satellite's final orbits and provided confirmation of reentry.
"We extend our appreciation to the Joint Space Operations Center (JSpOC) for monitoring UARS not only this past week, but also throughout its entire 20 years on orbit," said Nick Johnson from NASA's Johnson Space Center in Houston, Texas. "This was not an easy reentry to predict because of the natural forces acting on the satellite as its orbit decayed. Space-faring nations around the world also were monitoring the satellite's descent in the last 2 hours, and all the predictions were well within the range estimated by JSpOC."
UARS was launched September 12, 1991, aboard space shuttle mission STS-48 and deployed September 15, 1991. It was the first multi-instrumented satellite to observe numerous chemical components of the atmosphere for better understanding of photochemistry. UARS data marked the beginning of many long-term records for key chemicals in the atmosphere. The satellite also provided key data on the amount of light that comes from the Sun at ultraviolet and visible wavelengths. UARS ceased its scientific life in 2005.
Because of the satellite's orbit, any surviving components of UARS should have landed within a zone between 57° north latitude and 57° south latitude. It is impossible to pinpoint just where in that zone the debris landed, but NASA estimates the debris footprint to be about 500 miles (800 kilometers) long.