Astronauts Fix International Space Station Leak During Emergency Spacewalk

Astronauts fixed an ammonia coolant leak in the International Space Station on Saturday during an emergency spacewalk. The event was broadcast live on NASA Television and live-streamed on several websites.

The hastily planned spacewalk was undertaken by Christopher Cassidy and Thomas Marshburn, who replaced a pump outside the orbiting lab in the hopes of plugging the leak.

After the pump was replaced, the prospects of success grew as no frozen flecks of ammonia appeared. Mission Control reported that the leak was likely plugged, though it plans additional monitoring over the coming days, and possible weeks, before declaring victory over the problem.

Mission Control reported, “No evidence of any ammonia leakage whatsoever. We have an airtight system — at the moment.” Marshburn and Cassidy installed the new pump after removing the old one, which was suspected of spewing out the vital coolant into space.

During the spacewalk outside the International Space Station, the astronauts didn’t uncover any “smoking guns” responsible for the leak. While significant, NASA assured that the leak never jeopardized the safety of the crew. Despite this, managers wanted to fix the issue as soon as possible, before Marshburn returns to Earth in just a few days.

The spacewalk was the quickest, most impromptu spacewalk staged for a station crew. Even in the days of NASA shuttles, unplanned spacewalks were very uncommon. But flight controllers in Houston worked tirelessly to get ready for Saturday’s operation. They completed all the required preparation in under 48 hours.

Ammonia coolant coursing through the International Space Station’s plumbing is used to cool the structure’s electronic equipment, including its massive solar panels that power the station. There are eight power channels in all and seven of them have operated normally.

While the loss of one power channel doesn’t affect astronauts very much, the loss of two power channels could both threaten science experiments and backup equipment. Cassidy added, “We may not have found exactly the smoking gun … but to pull off what this team did yesterday and today, working practically 48 straight hours, it was a remarkable effort on everybody’s behalf.”

It’s still a mystery why the ammonia leak began on the International Space Station. While ammonia was already seeping somewhat from the location, the flow dramatically increased on Thursday. NASA’s space station program manager Mike Suffredini stated that possibilities include a micrometeorite strike of a flawed seal in the pump.

[Image via NASA]