BY DANIEL ALVAREZ
What goes up must come down. For satellites, that means coming down hard in a spiraling blaze of fire and dramatically breaking up in the sky, with any remains likely being scattered in the ocean. That was the fate of NASA’s Upper Atmosphere Research Satellite (UARS) Saturday Sept.24, in an uncontrolled re-entry into the atmosphere. “NASA’s Upper Atmosphere Research Satellite re-entered over the Pacific Ocean at 0400 GMT on Saturday, Sept. 24,” says Nick Johnson, NASA’s chief scientist for orbital decay, in a recorded statement. “It was generally in the vicinity of the Christmas Islands,” Johnson continued. “Because the re-entry occurred in the mid-Pacific Ocean, it’s unlikely that anyone actually observed the re-entry. We have not yet received any reports from passengers on airplanes or naval vessels … that would indicate anyone observed the debris.” The debris field left by UARS would be around 500 miles long, but, as any remains would have crashed into the Pacific, it’s very unlikely anything will ever be salvaged from it. There will be no legitimate viral videos of burning space debris streaking through the sky to share, despite several apparent hoaxes already making their way online. Others were concerned with possible damage to property or personal injury from falling space debris, because UARS’s re-entry was an uncontrolled descent. “In a controlled descent, you can determine where it will land with fuel, like Apollo, or any other controlled landing,” explained John Longworth, astronomy professor at SCAD. “In an uncontrolled landing, you have little to no idea where it’ll go.” NASA’s official Re-Entry and Risk Assessment of UARS states that the satellite never posed a threat, being “a moderate-sized space object,” and that “uncontrolled re-entries of objects more massive than UARS are not frequent, but neither are they unusual.” “During the past 50 years, an average of one cataloged, or tracked, piece of debris fell back to Earth each day. No serious injury or significant property damage caused by re-entering debris has been confirmed,” NASA’s website states. It goes on to say there are over 21,000 objects larger than four inches currently in orbit that count as orbital debris (excluding any operational space equipment). NASA launched UARS on Sept. 12, 1991, onboard the space shuttle mission STS-48, and deployed it three days later on Sept. 15. Its mission was to collect data on the chemical compounds in the atmosphere. UARS data helped scientists better understand o-zone photochemistry, as well as the processes that contribute to o-zone loss. In 2005, UARS moved into a disposable orbit, and was decommissioned by NASA. From then until its fall, UARS was essentially floating debris. On Sept. 7 2011, NASA announced the orbital decay and impending re-entry of the satellite and waited and observed to predict where and when it would land. “It’s all they can do,” said Longworth. “For the most part, everything in orbit will eventually do that.” In March 2001, the Russian space station, MIR, re-entered the atmosphere and burned up as it fell. If MIR and all its parts were able to burn up in the atmosphere without harming anyone, then there was probably never any true threat from the little satellite. Rest in peace, UARS.
