NASA troubleshooting coolant leak on space station
BY TODD HALVORSON Gannett News Service May 10, 2013 1:34AM
The International Space Station orbits at an altitude of about 220 miles above the Earth on May 23, 2011. NASA said Thursday that a radiator leak in its power system is a serious problem, but it's not life-threatening. | Paolo Nespoli~NASA via AP
Updated: May 10, 2013 1:34AM
CAPE CANAVERAL, Fla. — The International Space Station’s cooling system sprang a leak outside the outpost Thursday, raising the possibility of a partial system shutdown in the coming days, NASA officials said.
The six astronauts and cosmonauts aboard the station are in no danger. But the system is critical to dispelling heat generated during the operation of station systems, so flight controllers immediately began an effort to isolate the leak.
A partial shutdown of the cooling system could force the crew to stop some station operations until the problem is fixed.
Astronauts spotted small white flakes of frozen ammonia coolant leaking from the end of the station’s girder-like central truss.
The white flakes seeped from the same general area where spacewalkers successfully plugged an ammonia coolant leak in November.
In that case, astronauts Sunita “Suni” Williams of the United States and Akihiro Hoshide of Japan rerouted ammonia coolant lines to stop the leak.
NASA officials said it was unclear if the leak spotted Thursday is related to the earlier coolant system trouble.
The station’s 357-foot solar arrays generate electricity to power all outpost systems. Excess heat is built up as a result.
The outpost is outfitted with a thermal control system that pumps ammonia through coolant lines and ultimately radiators that shed excess heat.
Ammonia is highly toxic and exposure can cause burning of the eyes, nose and throat. High doses can cause coughing or choking and in extreme cases death. Spacewalkers take great caution when working with the outpost’s coolant system. Decontamination procedures are taught to all spacewalkers.
It was unclear Thursday whether a spacewalk would be required to stop the latest leak. The station crew used handheld cameras, and flight controllers in Mission Control used cameras mounted outside the outpost, in an attempt to pinpoint the location of the leak.
The imagery enabled systems engineers to gauge the rate of coolant leakage. They determined the leak could cause a partial cooling system shutdown within 48 hours if undeterred.
Plans are being put in place to reroute electrical power channels in an effort to maintain full operation of station systems that currently are cooled by the part of the system that is leaking.