A Walk in Space

Astronauts investigate a leak at the International Space Station

May 13, 2013 | By Cameron Keady with AP reporting

Chris Cassidy inspects the International Space Station on May 11.

There was some trouble in space over the weekend. On Thursday, May 9, flakes of frozen ammonia were seen drifting from the International Space Station (ISS). The team onboard immediately prepared for a spacewalk to look into the issue. Two days later, on Saturday, two astronauts stepped outside the ISS to investigate the leak. The chief suspect was an old ammonia pump.

Thomas Marshburn and Christopher Cassidy conducted the search, but did not discover any visible damage. "All the pipes look shiny clean, no crud," Cassidy reported as he used a mirror to peer into tight, deep openings. Even so, the astronauts removed the old pump and replaced it with a new one.

NASA astronauts Tom Marshburn and Chris Cassidy completed the May 11 spacewalk in 5 hours and 30 minutes.
NASA astronauts Tom Marshburn and Chris Cassidy completed the May 11 spacewalk in 5 hours and 30 minutes.

Keeping It Cool

Ammonia is used on the ISS to cool the spacecraft’s electronic equipment. NASA said this leak did not pose a safety threat to the six space station residents. But problems with the cooling system could threaten experiments and equipment.

It is still not clear why exactly the leak erupted. NASA speculates that a microscopic piece of space matter struck the space station, leaving a tiny crack in the ammonia pump. Another possibility is that there was simply a leaky seal in the pipe. Either way, “there’s nothing to lose by putting in a fresh pump and pressing ahead with additional detective work,” said Mission Control.

Studies in Space

The ISS was launched into orbit in 1998. Since 2000, a rotating crew of astronauts and scientists has continuously occupied it. While in orbit, the international team of astronauts performs scientific research and collects data about conditions in the Milky Way and beyond. Many of their experiments focus on humans’ ability to live and work in space over long periods of time.

While these astronauts have performed some amazing tasks, NASA has never before staged a spacewalk so quickly. Marshburn has been on the space station since December, and Cassidy is a new arrival to the ISS. While the leaky pump mystery continues to puzzle the ISS team, they are hopeful further investigations will provide answers. “This type of event is what the years of training were for,” space station commander Chris Hadfield said in a tweet Friday. “A happy, busy crew, working hard, loving life in space.”