(The Telegraph) ~ NASA has announced that a six-ton weather satellite is set to fall out of orbit, potentially raining debris over four continents.
The $750 million Upper Atmosphere Research Satellite, also known as UARS, was set in a 155-mile-high orbit by STS-Discovery in 1991, is 35 feet long, 15 feet in diameter and weights almost 12,000 pounds. It was designed to operate for three years, however six of its ten instruments are still working. But the satellite ran out of fuel in 2005 and is set to breach the upper atmosphere within the next few weeks. In a new alert, issued this week, officials warned pieces could land in densely populated areas, including parts of Europe, North America, South America and Asia.
NASA admitted more than half a ton of metal from the satellite will survive re-entry as the majority of debris will burn up after entering Earth’s atmosphere. NASA claims the risk to public safety is “extremely small” but admits they’re “concerned” about the risk to billions of people when the satellite starts to de-orbit. NASA’s orbital debris chief Gene Stansbury said, “things have been re-entering ever since the dawn of the space age; to date nobody has has been injured by anything that’s re-entered. This does not mean we’re not concerned.”
A NASA spokesman added, “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. It is too early to say exactly when UARS will enter and what geographic area maybe affected, but NASA is watching the satellite closely.” Scientists estimate the debris footprint will be about 500 miles long with a 1-in-3,200 chance that a satellite part could hit someone. The projected impact zone has also been narrowed to areas between 57º North and 57º South latitude.
UARS is currently being tracked by scientists at the Johnson Space Center in Houston, Texas and the Joint Space Operations Center of the US Strategic Command at Vandenberg Air Force Base, California. Those observers rely on radar and other deep-space telescopes around the world, making more than 80,000 observations of space every day. According to the US Space Surveillance Network, which monitors space junk, there are more than 22,000 objects measuring four inches or more currently in orbit around the Earth. The International Space Station occasionally has to move out of the way of passing debris. The volume of abandoned rockets, shattered satellites and missile shrapnel in orbit has reached a tipping point and is now threatening the $250 billion space services industry, according to the US Defense Department’s interim Space Posture Review. Meanwhile, the National Academy of Sciences admitted that scientists had “lost control” of the space environment in a report released earlier this month.
Photo credit: NASATags: nasa, orbit, re-entry, satellite, UARS, weather