Space.com (August 2, 2010)
"NASA is planning a pair of emergency spacewalks to repair the International Space Station after half of its cooling system shut down unexpectedly Saturday, forcing astronauts to power down several systems.
"The two repair spacewalks will be performed by American astronauts Doug Wheelock and Tracy Caldwell Dyson and could begin Thursday to replace a pump module in one of the space station's two cooling system loops. Engineers are assessing the spacewalk plans before making a final decision.
" 'They already have procedures for this,' NASA spokesperson Kelly Humphries told SPACE.com. 'This is a significant item and one that there has been a lot of work to prepare for. They're just working on the final details.'..."
The people equipment inside the International Space Station (ISS) generate quite a lot of heat. Since a vacuum is a pretty good insulator, that heat just builds up if something isn't done - hence the cooling systems. Or, right now, cooling system.
This has been an awkward weekend for the ISS crew:
"...The space station's cooling system troubles began late Saturday when a circuit breaker tripped and shut down the Loop A cooling system pump module, which is used to move super-cold liquid ammonia through the station to remove excess heat from its systems and laboratories...."
The good news? They're in no particular danger. There's still one cooling system that works.
The bad news? Since they had to shut down some of their equipment, they're not getting a lot done. And, that balky pump needs attention.
Which is the sort of maintenance that needs to be done, now and again, when you've got a large structure with lots of machinery in it: on the ground or in orbit. What makes this job different from fixing the air handling system in some office building is how many different countries are involved - and that the building is in orbit.
A few decades from now, that may not be so unusual. And that's another topic.
- "ISS Space Station Walkthrough, Looking Ahead"
(October 28, 2009)
- "ISS Sabatoge: The Big Questions is, Why?"
(July 26, 2007)
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