Live At KSC: Leaky Shuttle Vent Line Removed

LIVE IMAGES: The images above are from live video feeds in the Launch Complex 39 area at Kennedy Space Center, where Endeavour is being readied for a tentatively scheduled launch on July 11. They will automatically refresh to the most up-to-the-minute image every 30 seconds.

NASA contractor technicians removed shuttle Endeavour's leaky vent line at Kennedy Space Center's launch pad 39A today while managers prepared to select a date for a fuel-loading test that could clear the way for a July 11 launch attempt.

The test is a critical milestone.

If a planned fix doesn't work and dangerous levels of the highly flammable substance are detected again, NASA managers could be forced to switch out the shuttle's external tank and twin solid rocket boosters.

A move like that would trigger significant delays and make it more difficult for NASA to fly eight remaining shuttle missions and complete International Space Station assembly by the end of 2010.

Technicians earlier today removed the seven-inch line, which is designed to vent excess gaseous hydrogen from the shuttle's 15-story external tank while maintaining proper pressures within the giant propellant reservoir.

The gaseous hydrogen is routed to a nearby flare stack where it is safely burned away.

Higher-than-allowable leaks of gaseous hydrogen were detected during fuel-loading operations prior to planned launch attempts on June 13 and June 17. Engineers believe a rectangular port that links the vent line and the external tank was misaligned. The leading theory now is that an internal seal was consequently pulled out of place, creating a pathway for the gaseous hydrogen leaks.

NASA engineers have devised a plan to fix the misalignment and install an alternative seal that should keep any leak within acceptable levels.

The vent line and all associated hardware is being removed at the pad. Engineers will equip the line with the alternative seal and attempt to correct for the misalignment when the line is reinstalled in advance of the test, which is expected to take place next Tuesday or Wednesday.

Endeavour and seven astronauts are set to launch on a 16-day mission to deliver the third and final segment of the $1 billion Japanese Kibo science research facility to the International Space Station.

The launch delay from June to July pushed launch of a subsequent International Space Station outfitting mission from Aug. 7 to Aug. 18.