NASA Astronaut: Spacewalk Likely Needed To Fix Pump

A cooling pump on the International Space Station is still not working. The astronauts aren't in any immediate danger, and a backup is working, but decisions about cargo shipments are being delayed and astronauts may have to go on an unscheduled spacewalk to fix the problem.

NASA astronaut Tracy Caldwell Dyson joins Here & Now's Jeremy Hobson to discuss how NASA is tackling the problem. She spent about six months on the space station in 2010, and made three spacewalks during that time to repair a different part of the same cooling system.

Dyson says it's unlikely the astronauts will be able to fix the pump remotely.

"The engineers have been working feverishly to figure out what happened, but it's likely that the pump is unreachable and the component will have to be replaced," she says.

The truth about spacewalks

"They are a very serious event, and we're well trained for them, both the people in the spacesuits, as well as all the people on the ground supporting it. I guess you're very focused on what you're doing while you're out there. I saw the movie "Gravity," and the likelihood of something catastrophic like that coming at us without us knowing it are a lot slimmer than they were in the movie. We've got a lot of folks on the ground who are looking at all sorts of orbital debris possibilities, and if there were anything even remotely possible like that, we'd have some folks letting us know about it."

How the cooling pump works

"It circulates ammonia through a line that then goes through a heat exchanger and transfers heat from the water that circulates inside the space station. And the water that circulates inside the space station takes away all the heat from the equipment that we have inside and outside the space station."

What's it's like to return to Earth

"When you spend six consecutive months and all those minutes in microgravity and incredible sensations and sights that you get to experience, it is quite strange to be back on Earth. And many have made the same comment that once we arrive back here in Houston and we're with our families and in our familiar surroundings, it's just so bizarre that we were just in space 24 hours ago. It is a unique transition, and space is a hard place to leave, I'll say that much."