Astronauts prepare for possible spacewalks to fix ISS problems

[News_Editor]

WASHINGTON, D.C. (BNO NEWS) -- Astronauts aboard the International Space Station (ISS) are preparing for possible spacewalks to repair one of two cooling loops hit by a malfunction last week, NASA said on Sunday as engineers continued to monitor and regulate temperatures on the outpost.

The malfunction occurred on Wednesday when a valve that enables the flow of ammonia stopped positioning itself correctly, resulting in a drop of temperature in one of the station's two external cooling loops. It caused the loop to automatically shutdown after reaching pre-set temperature limits and prompting the shutdown of additional support systems.

Engineers scrambled over the weekend to move an isolation valve into a position that would help control temperatures in the affected loop, but it was not yet clear if the valve had been moved into the desired "sweet spot." Experts were also continuing to review data from the outpost and considering other techniques to help fix the problem.

Meanwhile, astronauts Rick Mastracchio and Michael Hopkins have readied their spacesuits and other equipment as NASA indicated on Sunday that it may attempt a series of spacewalks beginning Thursday to replace the faulty pump module. Technicians in Virginia were also preparing for a possible Thursday launch of an Antares rocket and the Cygnus cargo spacecraft on their first resupply mission to the space station.

"The International Space Station Program continues to keep both options on the table pending further engineering analysis and troubleshooting efforts on the station's cooling system," NASA said in a statement. It said crews have begun loading time-critical science cargo in the Cygnus spacecraft, which could be attached to the Antares rocket by Tuesday morning.

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