Christmas Eve spacewalk repairs broken cooling system at the International Space Station

US astronauts faced a 'mini blizzard' of ammonia during a rare spacewalk

Space station astronauts have repaired a crippled cooling system during a rare Christmas Eve spacewalk, braving a "mini blizzard" of toxic ammonia as they installed a new pump.

It was the second spacewalk in four days to be undertaken by US astronauts Rick Mastracchio and Michael Hopkins and took 7.5 hours to complete.

In a statement, Nasa said: "Following two spacewalks to replace a degraded pump module on the truss, or backbone, of the International Space Station, flight controllers in the Mission Control Center at NASA's Johnson Space Center in Houston successfully restarted the new pump Tuesday night."

Nasa ordered the spacewalk on Wednesday following the shutdown of one of the International Space Stations two ammonia cooling systems on 11 December, which forced the crew to turn off non-essential equipment and dozens of science experiments.

It has maintained that at no point have the astronauts been in danger.

Station commander cosmonaut Oleg Kotov, Mikhail Tyurin, Sergey Ryazanaskiy and Japanese astronaut Koichi Wakata are also aboard as part of Expedition 38.

Nasa said it expected the cooling system to be restored and all equipment back up and running by the weekend following yesterday's success.

"It's the best Christmas ever," Mission Control radioed as the spacewalk came to a close.

"Merry Christmas to everybody," replied Mr Hopkins. "It took a couple weeks to get her done, but we got it."

The astronauts removed the faulty ammonia pump during Saturday's spacewalk, before installing a new pump yesterday.

Standing on the end of the station's main robotic arm, Mr Hopkins clutched the 780lb, refrigerator-size pump with both hands as he headed toward its installation spot, and then slid it in.

An astronaut working inside, Japan's Koichi Wakata, steered the arm. The operation took longer to complete because of a faulty ammonia fluid line that sent frozen flakes of the extremely toxic substance straight at the men, Mission Control said.

The spacewalkers reported being surrounded by the flakes which bounced off their equipment.

The ammonia needed to dissipate from their suits before the pair returned inside, to avoid further contamination.

Christmas references filled the radio waves as the action unfolded 260 miles above the planet.

"It's like Christmas morning opening up a little present here," Mr Mastracchio said as he checked his toolkit.

Spacewalks were temporarily suspended in July when Italian spacewalker Luca Parmitano almost died after water began pouring into his helmet. The suits worn by Mastracchio and Hopkins have been modified with snorkels in case of another leak and absorbent pads to pick up the first signs of excess moisture inside their helmets.

Additional reporting by Associated Press

Start your day with The Independent, sign up for daily news emails
Sport
sportSo, how closely were you paying attention during 2014?
Arts and Entertainment
Dennis speaks to his French teacher
tvThe Boy in the Dress, TV review
News
One father who couldn't get One Direction tickets for his daughters phoned in a fake bomb threat and served eight months in a federal prison
people... (and one very unlucky giraffe)
Arts and Entertainment
Joel Edgerton, John Turturro and Christian Bale in Exodus: Gods and Kings
film
PROMOTED VIDEO
ebooks
ebooksA year of political gossip, levity and intrigue from the sharpest pen in Westminster
News
i100
Arts and Entertainment
The Plaza Theatre in Atlanta, Georgia was one of the 300 US cinemas screening
filmTim Walker settles down to watch the controversial gross-out satire
Arts and Entertainment
Amy Adams and Christoph Waltz in Tim Burton's Big Eyes
film reviewThis is Tim Burton’s most intimate and subtle film for a decade
Life and Style
Mark's crab tarts are just the right size
food + drinkMark Hix cooks up some snacks that pack a punch
Arts and Entertainment
Jack O'Connell stars as Louis Zamperini in Angelina Jolie's Unbroken
film review... even if Jack O'Connell is excellent
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Selby Jennings: VP/SVP Credit Quant- NY- Investment Bank

Not specified: Selby Jennings: VP/SVP Credit Quant Top tier investment bank i...

Ashdown Group: Senior Marketing Executive- City of London, Old Street

£40000 - £43000 per annum + benefits: Ashdown Group: Senior Marketing Executiv...

Ashdown Group: Marketing Manager

£40000 - £43000 per annum + benefits: Ashdown Group: An international organisa...

Ashdown Group: Internal Recruiter -Rugby, Warwickshire

£25000 - £30000 per annum: Ashdown Group: Internal Recruiter -Rugby, Warwicksh...

Day In a Page

Aren’t you glad you didn’t say that? The worst wince-and-look-away quotes of the year

Aren’t you glad you didn’t say that?

The worst wince-and-look-away quotes of the year
Hollande's vanity project is on a high-speed track to the middle of nowhere

Vanity project on a high-speed track to nowhere

France’s TGV network has become mired in controversy
Sports Quiz of the Year

Sports Quiz of the Year

So, how closely were you paying attention during 2014?
Alexander Armstrong on insulting Mary Berry, his love of 'Bargain Hunt', and life as a llama farmer

Alexander Armstrong on insulting Mary Berry and his love of 'Bargain Hunt'

From Armstrong and Miller to Pointless
Sanchez helps Gunners hold on after Giroud's moment of madness

Sanchez helps Gunners hold on

Olivier Giroud's moment of madness nearly costs them
A Christmas without hope: Fears grow in Gaza that the conflict with Israel will soon reignite

Christmas without hope

Gaza fears grow that conflict with Israel will soon reignite
After 150 years, you can finally visit the grisliest museum in the country

The 'Black Museum'

After 150 years, you can finally visit Britain's grisliest museum
No ho-ho-hos with Nick Frost's badass Santa

No ho-ho-hos with Nick Frost's badass Santa

Doctor Who Christmas Special TV review
Chilly Christmas: Swimmers take festive dip for charity

Chilly Christmas

Swimmers dive into freezing British waters for charity
Veterans' hostel 'overwhelmed by kindness' for festive dinner

Homeless Veterans appeal

In 2010, Sgt Gary Jamieson stepped on an IED in Afghanistan and lost his legs and an arm. He reveals what, and who, helped him to make a remarkable recovery
Isis in Iraq: Yazidi girls killing themselves to escape rape and imprisonment by militants

'Jilan killed herself in the bathroom. She cut her wrists and hanged herself'

Yazidi girls killing themselves to escape rape and imprisonment
Ed Balls interview: 'If I think about the deficit when I'm playing the piano, it all goes wrong'

Ed Balls interview

'If I think about the deficit when I'm playing the piano, it all goes wrong'
He's behind you, dude!

US stars in UK panto

From David Hasselhoff to Jerry Hall
Grace Dent's Christmas Quiz: What are you – a festive curmudgeon or top of the tree?

Grace Dent's Christmas Quiz

What are you – a festive curmudgeon or top of the tree?
Nasa planning to build cloud cities in airships above Venus

Nasa planning to build cloud cities in airships above Venus

Planet’s surface is inhospitable to humans but 30 miles above it is almost perfect