International Space Station in partial shutdown due to cooling pump problem
ISS facing coolant system problems [NBC News]

Crew members shut down minor systems to reduce power load, though Nasa says issue is not an emergency at the moment

A possible coolant leak on the International Space Station has led to a partial shutdown, NASA has said.

Astronauts hope to fix the problem by altering the software. But if that fails, at least one crew member will have to undertake a spacewalk.

NASA spokesman Kelly Humphries said the problem may eventually be serious, but was not currently an emergency.

Humphries said the external pump – part of one of the two cooling systems aboard the orbital outpost – stopped working but was now up and running.

The three Russians, two Americans and one Japanese crew members aboard shut down some minor operating systems to reduce the power load and engineers are trying to figure out if this is hardware or software problem.

NASA says the "ISS can stay in current configuration" until engineers can determine a fix, though that could take a week or two, according to NBC.

"The crew was never in any danger," NASA spokesman Josh Byerly told RIA Novosti. "They worked to keep the freezers going … They're fine for the near future."

The cooling system regulates the temperature on the ISS. Problems could result in uncomfortably high - or low - temperatures aboard the space station.

The exterior of the ISS experienced a coolant leak in May that required two astronauts to undertake a space walk to fix the problem.

There was no mention of any problems in the station's daily news update, which describes the range of work being carried out by the six crew, though it was later explained in a series of tweets from the ISS's feed.

© Guardian News and Media 2013

Watch a report from NBC News, aired on Wednesday, below.

Visit for breaking news, world news, and news about the economy