Spacewalking astronauts plug in new cooling pump

Aug 16, 2010 By MARCIA DUNN , AP Aerospace Writer
In a photo made from NASA television, Expedition 24 astronauts Tracy Caldwell Dyson and Douglas Wheelock work outside the space station Monday Aug. 16, 2010 as they prepare to install a cooling pump module, replacing the one that failed. (AP Photo/NASA)

(AP) -- Spacewalking astronauts installed a new ammonia pump to the International Space Station on Monday, accomplishing the urgent cooling-system repairs after more than two weeks of impaired operations in orbit.

Douglas Wheelock slid the bathtub-size pump into place 2 1/2 hours into the spacewalk, his third in just 10 days. He bolted the pump down as Tracy Caldwell Dyson hooked up power cables.

An initial test proved successful. "Sweet," Wheelock exclaimed.

With that hurdle behind them, the spacewalkers then began working on the ammonia fluid lines.

If all the testing proves successful, NASA expects to have the space station's disabled cooling loop back in action by Thursday.

The orbiting lab has been operating on only half its normal cooling capability ever since a crucial ammonia coolant pump failed July 31. It took two , but Wheelock and Caldwell Dyson finally removed the broken pump last week.

NASA said a fourth spacewalk eventually will be needed to move the failed pump into a better storage location, but managers are uncertain whether this crew or another will carry out the work.

The pumps - weighing 780 pounds apiece - are needed to drive ammonia through cooling loops and keep equipment from overheating. Four spare pumps were on board; the one installed Monday was the oldest of the bunch. It flew up in 2006.

Engineers are uncertain how and why an electrical short knocked out one of the two prime ammonia pumps two weeks ago. The breakdown left the space station with only one functioning cooling line and forced the six-person crew to turn off unnecessary equipment and halt science research.

NASA said the repair effort is one of the most challenging ever undertaken at the 12-year-old space station. Indeed, the astronauts' work was hampered by a large leak that erupted during the first spacewalk on Aug. 7.

A special team of engineers has been working practically nonstop ever since the trouble struck.

The is home to three Americans and three Russians. It's supposed to continue working until 2020, but that will become increasingly difficult to accomplish once NASA's shuttles stop flying next year. Two shuttle missions remain, with a third possible if the White House and Congress sign off on it.

Once the three remaining shuttles are retired, the Russian, European and Japanese space agencies will take over all crew and cargo shipments until NASA has a new rocket ready to go.

Explore further: Radar guards against space debris

0 shares

Related Stories

3rd spacewalk needed to restore cooling system

Aug 08, 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 ...

Space station astronauts fall short on repairs

Aug 07, 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 ...

Space station cooling system suddenly shuts down

Aug 01, 2010

(AP) -- Half of the International Space Station's cooling system suddenly shut down during the weekend, forcing the astronauts to power down equipment and face the likelihood of urgent spacewalking repairs.

Next space station spacewalk no earlier than Wednesday

Aug 09, 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 ...

NASA delays spacewalks to fix ISS cooling pump

Aug 05, 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. ...

Recommended for you

Radar guards against space debris

37 minutes ago

Space debris poses a growing threat to satellites and other spacecraft, which could be damaged in the event of a collision. A new German space surveillance system, schedu- led to go into operation in 2018, will help to prevent ...

Why we need to keep adding leap seconds

2 hours ago

Today at precisely 10am Australian Eastern Standard time, something chronologically peculiar will take place: there'll be an extra second between 09:59:59 and 10:00:00.

Helping Europe prepare for asteroid risk

3 hours ago

Each year, astronomers worldwide discover over 1000 new asteroids or other space rocks that could strike our planet. And if one is spotted heading towards Earth, experts working in ESA and national emergency ...

Image: Increasingly active Comet 67P

3 hours ago

On 13 August 2015, Comet 67P/Churyumov–Gerasimenko will reach its closest point to the Sun along its 6.5-year long orbit. It will be around 185 million km from the Sun at 'perihelion', between the orbits ...

Image: Modeling Gaia's avionics on the ground

3 hours ago

A full-size working model of Gaia's internal systems arrived in Germany this week. The Avionics Model is mounted in a circular set-up representing the systems on the actual satellite, now orbiting the Sun–Earth ...

User comments : 0

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.