Official: NASA's UARS Re-Enters Earth's Atmosphere
Talk about a (non) media event... NASA's decommissioned Upper
Atmosphere Research Satellite (UARS) fell back to Earth between
11:23 p.m. EDT Friday, Sept. 23 and 1:09 a.m. Sept. 24, 20 years
and nine days after its launch on a 14-year mission that produced
some of the first long-term records of chemicals in the
atmosphere.
The precise re-entry time and location of debris impacts have
not been determined. During the re-entry 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 re-entry, 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, could
have survived the fiery re-entry and reach the surface of
Earth.
However, NASA is not aware of any reports of injury or property
damage.
The Operations Center for JFCC-Space, the Joint Functional
Component Command at Vandenberg Air Force Base, Calif., 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 re-entry.
"We extend our appreciation to the Joint Space Operations Center
for monitoring UARS not only this past week but also throughout its
entire 20 years on orbit," said Nick Johnson, NASA's chief
scientist for orbital debris, at NASA's Johnson Space Center in
Houston. "This was not an easy re-entry 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 two hours and all the predictions
were well within the range estimated by JSpOC."
UARS was launched Sept. 12, 1991, aboard space shuttle mission
STS-48 and deployed on Sept. 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 degrees north
latitude and 57 degrees 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 long.