Astronauts embark on second spacewalk to fix cooling system

August 11, 2010

NASA astronauts aboard the International Space Station Wednesday began a second spacewalk to work on repairing a failed cooling system, the space agency said.

Astronauts Doug Wheelock and Tracy Caldwell Dyson suited up and switched to independent power in the space station airlock at 1227 GMT, initiating the walk in space.

Once outside the station, they will work to unhook and remove a busted pump module that caused the cooling problem in preparation for attaching a replacement.

"If all goes as planned, the spare pump will be installed during the third spacewalk," said the US space agency, adding that that operation would be possible "no earlier than Sunday."

Wheelock and Dyson's first spacewalk on Saturday lasted eight hours and three minutes, the sixth longest ever, but they were unable to remove the defective pump.

They disconnected three of four fluid lines connected to the pump but a fourth line leaked, causing them to stop work, said.

Conditions on the ISS remained stable and the station's six-person crew -- three Americans and three Russians -- was not in danger, NASA officials said.

If the efforts this week fail -- a highly unlikely scenario, NASA has said -- the astronauts would no longer be able to cool most of the space station components.

But the crew would not be in danger because they could move to the Russian segment of the ISS, which has its own cooling system.

According to NASA figures, without thermal controls the ISS's sun-facing side would roast at 250 degrees Fahrenheit (121 Celsius), while the outpost's dark side would plunge to some minus 250 degrees Fahrenheit (minus 157 Celsius).

The ISS, which orbits 350 kilometers (220 miles) above Earth, is a sophisticated platform for scientific experiments.

It is a 100-billion-dollar cooperation between 15 countries, and has been manned uninterrupted since October 1990.

Explore further: NASA plans two challenging spacewalks to fix ISS pump (Update)

Related Stories

NASA delays spacewalks to fix ISS cooling pump

August 5, 2010

NASA on Thursday pushed back by one day the first of two spacewalks to fix a pump module on the International Space Station's (ISS) cooling system that dramatically failed last week.

Space station astronauts fall short on repairs

August 7, 2010

(AP) -- A pair of space station astronauts had to hammer loose a stuck connector Saturday during an urgent spacewalk to restore a crucial cooling system, and ran out of time before they could remove a broken pump.

3rd spacewalk needed to restore cooling system

August 8, 2010

(AP) -- A pair of space station astronauts had to hammer loose a stuck connector during an urgent spacewalk to restore a crucial cooling system Saturday, then an ammonia leak erupted and hampered the entire repair effort.

Next space station spacewalk no earlier than Wednesday

August 9, 2010

Flight controllers and engineers continue meetings to review the results from the first spacewalk conducted Saturday by International Space Station Expedition 24 Flight Engineers Doug Wheelock and Tracy Caldwell Dyson and ...

Recommended for you

The search for molecular oxygen among cosmic oxygen atoms

July 27, 2015

Oxygen is the third most abundant element in the universe (after hydrogen and helium) and of course it is important: all known life forms require liquid water and its oxygen content. For over thirty years, astronomers have ...

Hubble looks in on a galactic nursery

July 27, 2015

This dramatic image shows the NASA/ESA Hubble Space Telescope's view of dwarf galaxy known as NGC 1140, which lies 60 million light-years away in the constellation of Eridanus. As can be seen in this image NGC 1140 has an ...

Fossil star clusters reveal their age

July 27, 2015

Using a new age-dating method, an international team of astronomers has determined that ancient star clusters formed in two distinct epochs – the first 12.5 billion years ago and the second 11.5 billion years ago.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.