Watch NASA spacewalk live

NASA astronauts are currently outside the International Space Station on a spacewalk, and NASA is streaming the action live.

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NASA astronaut Chris Cassidy and the European Space Agency’s Luca Parmitano are participating in the spacewalk, which is scheduled to last a total of 6.5 hours. They’ll be replacing a failed communications controller along with other maintenance tasks as well as retrieving a few external experiments that will be returning home via a SpaceX Dragon cargo capsule later this year.

Above: A cosmic screwdriver.

Image Credit: NASA

The most pressing task, however, has been to fix the liquid ammonia cooling system that powers one of the station’s solar arrays. Just days ago, astronauts discovered little white flakes floating away from the ISS, which turned out to be an ammonia leak. The spacewalk was quickly scheduled to look into the leak, making this one of the most unplanned spacewalks ever in spite of the long lists of tasks.

Another task is rerouting power cables that will be supporting the coming Multipurpose Laboratory Module, which is scheduled to arrive from Russia near the end of 2013.

There’s not always a lot to see, and the action is not fast, but some of the shots are spectacular … and this is live footage from space.

Interestingly, some of it is first-person video obviously shot from an astronaut’s helmet cam, showing you exactly what the astronauts are working on. Typical commentary from NASA controllers includes information on what the astronauts are doing as well as safety tips for the astronauts themselves, such as, “We’re about 15 minutes to sunrise, so you probably want to adjust your visors and your heaters if you need to.”