This article is from the source 'bbc' and was first published or seen on . It last changed over 40 days ago and won't be checked again for changes.
You can find the current article at its original source at http://www.bbc.co.uk/news/science-environment-22492521
The article has changed 4 times. There is an RSS feed of changes available.
| Version 1 | Version 2 |
|---|---|
| Astronauts perform emergency spacewalk to repair leak | |
| (about 3 hours later) | |
| Two US astronauts are carrying out an emergency spacewalk to fix a leak of ammonia from the International Space Station's cooling system. | |
| Live video shows Chris Cassidy and Tom Marshburn examining the outside of the craft to search for the escape. | Live video shows Chris Cassidy and Tom Marshburn examining the outside of the craft to search for the escape. |
| The crew had spotted particles of ammonia drifting away from the laboratory on Thursday. | The crew had spotted particles of ammonia drifting away from the laboratory on Thursday. |
| It is expected the spacewalk, prepared at record short notice, will last around six and a half hours. | It is expected the spacewalk, prepared at record short notice, will last around six and a half hours. |
| 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. | 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 on the ISS are not in any danger. | Nasa says the crew on the ISS are not in any danger. |
| The leak 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. | The leak 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. |
| The astronauts will "inspect and possibly replace" a pump controller box in that area of the space station, according to Nasa. | The astronauts will "inspect and possibly replace" a pump controller box in that area of the space station, according to Nasa. |
| Commander Chris Hadfield reported seeing "a very steady stream of flakes" on Thursday. | Commander Chris Hadfield reported seeing "a very steady stream of flakes" on Thursday. |
| "They were coming out cleanly and repeatedly enough that it looked like it was a point source they were coming from," he added. | "They were coming out cleanly and repeatedly enough that it looked like it was a point source they were coming from," he added. |
| It is not the first time that the station's cooling systems have caused problems. | It is not the first time that the station's cooling systems have caused problems. |
| A very small leak was identified in 2007 in the same location, and a spacewalk was organised in 2012 to reconfigure coolant lines and isolate the problem. | A very small leak was identified in 2007 in the same location, and a spacewalk was organised in 2012 to reconfigure coolant lines and isolate the problem. |
| The station currently has a crew of six. Commander Hadfield, a Canadian, is due to leave the platform with American astronaut Tom Marshburn and Russian cosmonaut Roman Romanenko on Monday. | The station currently has a crew of six. Commander Hadfield, a Canadian, is due to leave the platform with American astronaut Tom Marshburn and Russian cosmonaut Roman Romanenko on Monday. |
| Cmdr Hadfield had asked mission controllers if the leak might prevent the undocking of his return capsule. They responded that there was no technical reason why it should, but that engineers would update the crew once they understood the issues more fully. | Cmdr Hadfield had asked mission controllers if the leak might prevent the undocking of his return capsule. They responded that there was no technical reason why it should, but that engineers would update the crew once they understood the issues more fully. |