UARS Re-Entry Overview

    Final Update: NASA's UARS Re-enters Earth's Atmosphere

    NASA’s decommissioned Upper Atmosphere Research Satellite fell back to Earth at 12 a.m. EDT (0400 GMT), as Friday, Sept. 23, turned to Saturday, Sept. 24 on the United States east coast. The Joint Space Operations Center at Vandenberg Air Force Base in California has determined the satellite entered the atmosphere over the Pacific Ocean at 14.1 degrees south latitude and 189.8 degrees east longitude (170.2 west longitude). This location is over a broad, remote ocean area in the Southern Hemisphere, far from any major land mass. The debris field is located between 300 miles and 800 miles downrange, or generally northeast of the re-entry point. NASA is not aware of any possible debris sightings from this geographic area.

    This is your source for official information on the re-entry of UARS. All information posted here has been verified with a government or law enforcement agency. This is NASA's final status report on the re-entry of UARS.

    UARS re-entry map. Credit: NASAThis map shows the ground track for UARS beginning in the Indian Ocean off the coast of Africa at 0330 GMT and ending at atmospheric interface over the Pacific Ocean at 0400 GMT.

    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. 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.

    Nick Johnson, NASA's chief scientist for orbital debris, discusses the re-entry:


    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.

    Additional resources:

    › NASA News Release, Sept. 24, 2011
    › Re-Entry and Risk Assessment (498 KB PDF)
    › Frequently Asked Questions: Orbital Debris

    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

    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.

    › UARS Science Accomplishments
> UARS Legacy Website

Features

  • artist concept of uars

    Solar Activity Can Affect Re-Entry of UARS Satellite

    It isn't easy to predict when a satellite like UARS will re-enter Earth's atmosphere, since the space it travels through changes density over time due to incoming particles and radiation energy from activity on the sun.

xmlns:xsl='http://www.w3.org/1999/XSL/Transform'">

UARS Image