July 1, 2009

Endeavour Passes Fuel Test, On Target For July 11 Launch

A test early Wednesday morning of the space shuttle Endeavour's fueling system found no significant hydrogen gas leaks, clearing the way for an upcoming launch on July 11.

A potentially dangerous hydrogen gas leak discovered last month had delayed two prior launch attempts.

But Wednesday's three-hour test, in which launch controllers filled the external fuel tank to see if repairs had stopped the leak, detected no abnormalities.

"The preliminary results indicated the repairs were successful," said NASA spokeswoman Candrea Thomas.

The successful completion of the test means NASA can proceed with its launch attempt on July 11.  The 16-day mission calls for Endeavour to deliver one final piece of a Japanese space station lab to the International Space Station (ISS).

During the two previous launch attempts in mid-June, substantial amounts of hydrogen gas escaped from a plate on Endeavour's fuel tank that connects to a vent line.

NASA's engineers believe a small misalignment of less than one degree of the plate was the culprit.  They have since installed a different, softer type of seal, and have installed special washers to correct the problem.

"We think we've got it licked," test director Steve Payne told the Associated Press.

Commander Mark Polansky monitored the test from Houston, and was happy with the results.

"So far, so good," he wrote in an update posted to the Twitter Web site.

Polansky and his six crewmates will deliver and install the Japanese lab section to the ISS, where they will spend nearly two weeks working with a six-member crew already onboard.  The mission will achieve a record for the largest number of people together in orbit.


Image Caption: Space shuttle Endeavour is revealed on Launch Pad 39A at NASA's Kennedy Space Center in Florida during a tanking test July 1. Image credit: NASA TV


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