It's been over a year since NASA curtailed outside spacewalks for its astronauts on the International Space Station (ISS), but today, NASA astronaut Reid Wiseman is doing just that, pairing up with the ESA's Alexander Gerst, for routine maintenance that involves moving a broken pump from the ISS to storage.

Last year, the U.S. stopped all spacewalks by its astronauts after the ammonia-based cooling system flooded the helmet of an Italian astronaut and nearly drowned the man. 

NASA fixed the issue with the helmet's water-cooling system, but, unfortunately, that wasn't the only problem. There were also issues with the spacesuit's batteries, which delayed spacewalks by several months. However, new batteries arrived at the ISS last week, thanks to a SpaceX cargo shuttle.

The work being done by Wiseman and Gerst involves moving a broken 780 pound pump sitting in a temporary storage area to a long-term storage area. The pipe was replaced last year with an emergency spacewalk. The two astronauts will also replace a video camera light and do some electrical work to route power to the mobile transporter that moves a large robotic arm.

Both Wiseman and Gerst are making their first spacewalks today, and tweeted about the experience.

Hey @astro_reid let's take a walk on the wild side... #spacewalk #EVA27

— Alexander Gerst (@Astro_Alex) October 7, 2014

I think I’ll go on a little #spacewalk with @astro_alex tomorrow. Feeling all emotions right now. — Reid Wiseman (@astro_reid) October 6, 2014

A second spacewalk will happen on October 15. Another NASA astronaut, Butch Wilmore, joins Wiseman for that mission, which will replace failed equipment on the American side of the ISS. NASA expects up to 10 more spacewalks in the next year to prepare for future arrivals of commercial crew spacecraft. 

"All that is in preparation for being able to support future commercial crewed vehicles coming to station. We're trying to get out in front of that," says Kenny Todd, space station integration and operations manager. "We'll be prepping for moving modules, we'll be installing a new docking adapter system. All of that will be happening throughout the next several months."

The current spacewalk will take about six and a half hours. You can watch the entire mission live now on NASA TV.