Space Station Cooling Unit Breakdown May Need Spacewalk Fix

A faulty valve in one of the space station's cooling units may require an emergency spacewalk to assess damage and conduct repair. Credit: NASA
A faulty valve in one of the space station’s cooling units may require an emergency spacewalk to assess damage and conduct repairs. Credit: NASA

Update: NASA has indeed decided to dispatch International Space Station astronauts on a series of spacewalks to repair the faulty cooling pump. A NASA briefing on the space walks will take place on December 18 at 3 p.m. The space walks have also forced the delay of a cargo resupply mission to the space station.

A major cooling crisis is apparently brewing on the $100 billion International Space Station (ISS), home to six astronauts.

One of two major cooling system pumps aboard the space station suffered a partial shut-down on Wednesday, December 11, according to NASA officials. The cooling system acts like a car’s radiator to remove excess heat from the orbiting lab, and the pump was shut off due to temperature fluctuations.

This has left the ISS with about half its normal cooling capability, leaving NASA ground controllers no choice but to shut down nonessential systems—including science experiments—to prevent possible overheating and damage to the space station.

“Earlier Wednesday, the pump module on one of the space station’s two external cooling loops automatically shut down when it reached pre-set temperature limits,” NASA said in a website statement.

These external loops circulate ammonia outside the station to keep both the space station’s internal and external equipment cool. “The flight control teams worked to get the cooling loop back up and running, and they suspect a flow control valve actually inside the pump module itself might not be functioning correctly,” says the statement.

While NASA says it plans for malfunctions like these to crop up every once in a while and that the astronauts themselves are not in any danger now–it doesn’t make it any less urgent to find a fix for the ailing orbiting laboratory.

NASA engineers have been working all night to find a fix—investigating whether the problem might be either a software or hardware glitch—and they now suspect the culprit is a malfunctioning valve.  This same valve was replaced by spacewalking astronauts three years ago.

If confirmed, the crew on-board will need to carry out an emergency spacewalk to replace the module.

In May, a leak in one of the space station’s radiators was discovered, requiring a hastily planned spacewalk to assess damage and conduct repairs. (See also: Serious Space Station Leak Provokes Weekend Spacewalk)

Complicating matters and making the possibility of spacewalks a bit more worrisome is the scary near-drowning incident in July, when Italian astronaut Luca Parmitano’s helmet began filling up with water during a routine maintenance spacewalk. While the spacesuit has been inspected, it is still on-board and may very well be used again.

So, it’s not surprising that on Thursday morning NASA officials said that they are still working on possible fixes that could avoid a spacewalk. Meanwhile the ISS crew will have to remain on a reduced work  schedule.

Ground controllers are also trying to determine if this crisis might somehow effect the upcoming launch of the private Cygnus unmanned resupply ship scheduled for December 18.

Stay tuned for further updates….


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Changing Planet

Andrew Fazekas, aka The Night Sky Guy, is a science writer, broadcaster, and lecturer who loves to share his passion for the wonders of the universe through all media. He is a regular contributor to National Geographic News and is the national cosmic correspondent for Canada’s Weather Network TV channel, space columnist for CBC Radio network, and a consultant for the Canadian Space Agency. As a member of the Royal Astronomical Society of Canada, Andrew has been observing the heavens from Montreal for over a quarter century and has never met a clear night sky he didn’t like.