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Hydrogen leak stops space race on pad; shuttle Endeavour grounded
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Racing against time and the weather, NASA tried to launch space shuttle Endeavour and its STS-127 crew, but a mysterious repeating gaseous hydrogen leak on ground equipment foiled their plans. In a rare episode that seemed straight from Hollywood, launch managers decided to try and make up time despite a weather-related three-hour delay in loading the giant fuel tank.
Engineers had never before tried to make up so much time in the fueling process. The 15-story tank, which carries more than 500,000 gallons of explosive requires three hours to fill, pushing the end of the operation right up to the edge of astronaut entry into the shutte. The tanking operation, originally planned to begin at 8:15 p.m. EDT was delayed for just about three hours as dangerous lightning and thunderstorms whipped through the area.
Already working against a previous launch scrub on June 13 and the bumping of a NASA robotic moon mission to get today's launch time, the mission team decided to push on with the launch as soon as weather cleared. They added another technician to assist with crew loading into the spacecraft and tried to consolidate other tasks to make the 5:40 a.m. EDT launch time.
With only a ten-minute window to launch, and limited time on the Eastern Test Range (ETR), the shuttle teams worked frantically trying to pull things together. But once again, a leak near the Ground Umbilical Carrier Plate, or GUCP, which attaches to the external tank at its intertank area. cropped up. The line leads from the GUCP back to the launch pad and to the "flare stack" where vented gaseous hydrogen is burned off.
Engineers cycled the valve several times, starting and stopping the fueling process. With new storm clouds moving in, the launch attempt was called off at 1:55 a.m EDT. The call to scrub came only a few minutes before the astronauts were to begin putting on their space suits in KSC's Operations & Checkout (O&C) building.
Next up: troubleshooting the leak problem, which also delayed the launch of Discovery and the STS-119 mission in March. The team will also have to select a new launch date for the mission, which could impact STS-128, set to launch in July. With the build-up for the new Ares rocket, one launch pad has been turned over to the Constellation program, giving the shuttle program only one usable launch site.
Up next: a new moon mission. NASA negotiated with itself to bump the moon shot to later this week and give the June 17 slot to the shuttle.
NASA's Lunar Reconnaissance Orbiter and Lunar Crater Observation and Sensing Spacecraft will fly to the moon atop the same Atlas V rocket, although they will use vastly different methods to study the lunar environment. LRO will go into orbit around the moon, turning its suite of instruments towards the moon for thorough studies. The spacecraft also will be looking for potential landing sites for astronauts.
LCROSS, on the other hand, will guide an empty upper stage on a collision course with a permanently shaded crater in an effort to kick up evidence of water at the moon's poles. LCROSS itself will also impact the lunar surface during its course of study.
Liftoff currently is scheduled for June 18 at 5:12 p.m. EDT. There are two more launch opportunities that day at 5:22 p.m. and 5:32 p.m.
NASA managers promised more information later about plans for another Endeavour liftoff date. The launch team now is moving through the draining of the fuel tank, followed by procedures to safe it before work crews can access the hardware tomorrow night.
Note to new readers: to learn more about the background of this story, simply click on the underlined text to go to my previous related stories.
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