Cygnus Launch May Be Delayed Due To Ongoing Coolant Issue On ISS
December 13, 2013

Cygnus Launch May Be Delayed Due To Ongoing Coolant Issue On ISS

redOrbit Staff & Wire Reports - Your Universe Online

NASA is still evaluating the International Space Station (ISS) cooling issue that forced a partial shutdown of the facility, but officials with the agency told reporters Friday that a faulty valve in an external pump is the most likely culprit.

According to Gina Sunseri of ABC News, NASA officials have multiple teams working on a solution to the issue. Known as “tiger teams,” these units will present their findings to the mission management team, which will be meeting throughout the next few days to weigh their options when it comes to a potential fix.

“Engineers hope to find a software solution for the stuck valve on the pump,” Sunseri said. “A spacewalk is no one's first choice to solve the problem if an engineer in Mission Control can upload a patch, or hit a reset button. By Monday, mission managers will decide if a spacewalk or two is needed to fix the broken pump.”

NASA officials reiterated that the issue could be serious but is not life-threatening, telling Reuters reporter Irene Klotz that the six crew members (three Russians, two Americans and one Japanese) currently stationed on the orbiting laboratory were in no danger and would not need to be evacuated. Equipment effected by the issue, which includes a trio of freezers containing science samples, has either been shut off or switched over to the station’s other cooling loop.

“Some of the news reports that I've seen out there have been like 'catastrophic shutdown.' That's not at all what this is,” NASA spokesman Josh Byerly told Reuters from the Johnson Space Center in Houston. “If it's a software problem, they could just do a software update or do a patch. If it's a hardware issue, that's something else. We'll know more in the next day or so.”

On Wednesday, the pump module on one of the two ISS external cooling loops used to circulate ammonia outside of the station automatically ceased operations after reaching pre-set temperature limits. The flow control valve regulates the ammonia’s temperature, so that when it is re-introduced into the heat exchanged, it does not freeze the water that also flows through the exchanger, NASA explained in a statement Thursday.

“The science and research mission continues aboard the station, and the science data collected so far is not at risk,” the agency added. However, the issue could force a delay of the launch of the Orbital Sciences’ Cygnus commercial cargo craft, which is currently expected to lift off on December 18 and rendezvous with the ISS three days later. Mission managers have deferred that decision until more is known about the flow control valve issue.