ISS: Space station's cooling system leaking ammonia

FROM BBC NEWS: 

NASA

Astronauts on the International Space Station are dealing with a leak in the orbiting platform's cooling system.

The crew spotted particles of ammonia drifting away from the laboratory on Thursday.

Liquid ammonia is used to extract the heat that builds up in electronic systems, dumping that excess energy to space through an array of radiators.

Nasa says the crew is in no danger, but that a spacewalk may be needed to inspect the site of the leak.

The seepage is coming from the station's port side, at the far end of the backbone, or truss, structure that holds one of the laboratory's huge sets of solar arrays.

Commander Chris Hadfield reported seeing "a very steady stream of flakes".

"They were coming out cleanly and repeatedly enough that it looked like it was a point source they were coming from," he added.

Cameras were trained on the location so that engineers on the ground could get a better idea of what was happening.

Hadfield later tweeted: "It is a serious situation, but between crew and experts on the ground, it appears to have been stabilized."

Nasa believes the problem is associated with the 2B power channel, one of eight fed by the station's solar arrays.

It is not the first time that the station's cooling systems have caused problems.

A very small leak was identified in 2007, and in 2010 a complete failure of an ammonia pump led to three spacewalks to replace it.

In 2012, a spacewalk was organised to reconfigure coolant lines and isolate the problem of leaks.

Nasa said in a statement that the rate of loss of ammonia on Thursday meant the cooling loop would very likely have to be shutdown, although it stressed this would not cause the station or its occupants any difficulty.
http://www.bbc.co.uk/news/science-environment-22478364