The ammonia pump was the chief suspect going into Saturday’s spacewalk. So it was disheartening for NASA, at first, as Cassidy and Marshburn reported nothing amiss on or around the old pump.
“All the pipes look shiny clean, no crud,” Cassidy said as he used a long, dentist-like mirror to peer into tight, deep openings.
“I can’t give you any good data other than nominal, unfortunately. No smoking guns.”
Engineers determined there was nothing to lose by installing a new pump, despite the lack of visible damage to the old one. The entire team – weary and stressed by the frantic pace of the past two days – gained more and more confidence as the 5 1/2-hour spacewalk drew to a close with no flecks of ammonia popping up.
“Gloved fingers crossed,” space station commander Chris Hadfield said in a tweet from inside. “No leaks!” he wrote a half-hour later.
Flight controllers in Houston worked furiously to get ready for the operation, completing all the required preparation in under 48 hours. The astronauts trained for just such an emergency scenario before they rocketed into orbit.
This area on the space station is prone to leaks.
The ammonia coursing through the plumbing is used to cool the space station’s electronic equipment. There are eight of these power channels, and all seven others are operating normally.
Life for the six space station residents has been pretty much unaffected since the ammonia shower. The loss of an additional power channel, however, could threaten science experiments and backup equipment.
“We may not have found exactly the smoking gun,” Cassidy said, “but to pull off what this team did yesterday and today, working practically 48 straight hours, it was a remarkable effort on everybody’s behalf.”
NASA officials remain mystified as to why the leak erupted. Ammonia already had been seeping ever so slightly from the location, but the flow increased dramatically.
Montalbano did not know how much ammonia was lost. Another spacewalk will be needed to replenish the supply.
With the repair work behind them, the astronauts and ground controllers turned their attention to the impending departure of three of the six crewmen.
Marshburn has been on the space station since December and is set to return to Earth, along with Hadfield, a Canadian, and Russian Roman Romanenko. Cassidy is a new arrival, on board for just 11/2 months.
By coincidence, the two Americans performed a spacewalk at this troublesome spot before, during a shuttle visit in 2009.<< previous 1 2 3