UPDATE from NASA 11:PM Fri:
NASA says it continues to wait for final confirmation of re-entry. “If debris fell on land (and that’s still a BIG if), Canada is most likely area,” the space agency just said.
Fri, 23 Sep 2011 07:50:07 PM PDT
As of 10:30 p.m. EDT on Sept. 23, 2011, the orbit of UARS was 85 miles by 90 miles (135 km by 140 km). Re-entry is expected between 11:45 p.m. Friday, Sept. 23, and 12:45 a.m., Sept. 24, Eastern Daylight Time (3:45 a.m. to 4:45 a.m. GMT). During that time period, the satellite will be passing over Canada and Africa, as well as vast areas of the Pacific, Atlantic and Indian oceans. The risk to public safety is very remote.
Lots of newsbuzz today on the Upper Atmosphere Research Satellite. Not since Skylab came down in 1979 has there been this much buzz over space junk burnup. I wonder if somebody will name their kid after it.
Just hours before re-entry, a baby boy was born in Patiala, India. He was named Skylab Singh. Source: “Baby Named Skylab.” Vancouver Sun 12 Jul. 1979: A7.
NASA’s Upper Atmosphere Research Satellite, or UARS, is expected to re-enter Earth’s atmosphere late Sept. 23 or early Sept. 24 Eastern Daylight Time, 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 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.
It is still 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. Visit this page for updates on the satellite’s orbital track and predicted re-entry date.
The updates posted here 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 time 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.
Because the satellite’s orbit is inclined 57 degrees to the equator, any surviving components of UARS will land 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 will land, but NASA estimates the debris footprint will be about 500 miles long.
If you find something you think may be a piece of UARS, do not touch it. Contact a local law enforcement official for assistance.
UARS Science Accomplishments
An artist’s concept shows UARS in Earth orbit. Credit: NASA NASA’s UARS satellite, launched in 1991 from the Space Shuttle, was the first multi-instrumented satellite to observe numerous chemical constituents of the atmosphere with a goal of better understanding atmospheric photochemistry and transport.
Many of these studies centered on the early understanding of ozone photochemistry. The timing of the UARS launch could not have been better. At that time, there were many open questions as to the details surrounding stratospheric ozone loss, especially with the processes related to the Antarctic ozone hole. UARS data were uniquely designed to address those questions.
Also, just before the launch of UARS, the eruption of Mt. Pinatubo occurred in the Philippines, pumping significant amount of sulfuric acid aerosols into the tropical stratosphere. Atmospheric transport spread these aerosols around the global stratosphere over the next year, affecting both the chemistry and the temperature and radiative balance of the atmosphere.
UARS data also marked the beginning of numerous long-term data records for many key chemical species in the atmosphere. These data are now being combined with more recent data sets (especially from NASA’s Aura satellite) to better understand how the atmosphere reacts to the policies set down by the Montreal Protocol as well as changes in climate drivers.
UARS also provided key data on the amount of light that comes from the sun at ultraviolet and visible wavelengths. Those data were key for better understanding the radiative balance of the stratosphere and mesosphere and for the photochemistry in those parts of the atmosphere.
UARS ceased its productive scientific life in 2005.