Pieces Of 1,400-Pound Coolant Tank Will Survive Re-Entry
The National Aeronautics and Space Administration and the US
Space Surveillance Network are tracking a 1,400-pound tank of toxic
ammonia coolant jettisoned over a year ago from the International
During the last year, the ammonia tank's orbit has slowly
degraded due to gravity and atmospheric drag. Expected to re-enter
Earth's atmosphere Sunday afternoon or evening, the exact location
where the refrigerator-sized tank will land remains unknown.
In a recent interview, NASA space station program manager Mike
Suffredini said, "This has got a very low likelihood that anybody
will be impacted by it. But still, it is a large object and pieces
will enter and we just need to be cautious."
NASA expects as many as 15 pieces of the tank to survive the
intense heat of re-entry, ranging in size from about 1.4 ounces to
nearly 40 pounds, according to MSNBC.
The largest piece of orbital trash ever tossed overboard, the
Early Ammonia Servicer coolant tank was discarded by NASA astronaut
Clayton Anderson during a July 23, 2007 spacewalk. An unneeded
212-pound video camera stand was jettisoned at the same time,
burning up harmlessly in its descent through the atmosphere earlier
this year, Suffredini said.
The tank was originally used as a coolant reservoir, boosting
the Space Station's cooling system in the event of leaks. Last
year's upgrades to the station made the tank obsolete, but
engineers were doubtful it could withstand a ride back to Earth
aboard a NASA space shuttle.
"As a matter of course, we don't throw things overboard
haphazardly," Suffredini said. "We have a policy that has certain
criteria we have to meet before you can throw something
While astronauts have accidentally lost a tool or two during
spacewalks, the planned jettison of larger items is done with the
utmost care to ensure the trash doesn't hit the station or any
other spacecraft as it circles the Earth, Suffredini said.
Engineers also make sure the risk to people on Earth is low.
Should re-entry occur over land, NASA advises that the public
should contact local authorities, or the US Department of State via
diplomatic channels if outside of the US, if they believe they've
found the remains of the tank.
"If anybody found a piece of anything on the ground Monday
morning, I would hope they wouldn't get too close to it,"