NASA astronaut Clayton Anderson, an Expedition 15 flight engineer, tosses a hefty unneeded ammonia tank (the size of a refrigerator) overboard from the space station during a July 23, 2007 spacewalk. A piece of space station trash is poised to plunge through the Earth’s atmosphere late Sunday, November 2, 2008.
NASA and the US Space Surveillance Network are tracking the object – a 1,400-pound tank of toxic ammonia coolant thrown from the international space station – to make sure it does not endanger people on Earth.
NASA expects up to 15 pieces of the tank to survive the searing hot temperatures of re-entry, ranging in size from about 1.4 ounces to nearly 40 pounds. If they reach all the way to land, the largest pieces could slam into the Earth’s surface at about 100 mph, but a splashdown at sea is also possible.
It’s taken more than year for the ammonia tank to slowly slip down toward Earth due to atmospheric drag. During its time aboard the station, the tank served as a coolant reservoir to boost the outpost’s cooling system in the event of leaks. Upgrades to the station last year made the tank obsolete, and engineers were concerned that its structural integrity would not withstand a ride back to Earth aboard a NASA space shuttle.
In the event the tank re-enters over land, NASA advised members of the public to contact their local authorities, or the U.S. Department of State via diplomatic channels if outside the U.S., if they believe they’ve found its remains.