The American space agency calls off the launch of the shuttle because of a potentially hazardous hydrogen leak.
Shuttle launch put on hold
NASA has called off the launch of its shuttle Endeavour for the second time in four days after discovering a small but potentially hazardous hydrogen leak, the US space agency said. "At 1.55am, launch managers called a scrub, cancelling today's planned launch of space shuttle Endeavour on its STS-127 mission," NASA said in a statement. "Despite troubleshooting efforts, engineers were unable to achieve a decrease in the liquid hydrogen leak," the agency said, adding that the leak was in the same spot that halted the previous launch attempt on Saturday.
The previous leak was in the venting system supposed to carry excess hydrogen safely away from the launch pad. Shuttle launch director Pete Nickolenko had admitted during intense repair efforts on Sunday that the original leak's root cause was still not determined. The three-hour operation to pump 500,000 gallons to the shuttle tanks was begun late yesterday for a launch to the International Space Station at 5.40am.
With the second scrub, however, the next possible lift-off may not be until July 11 at the earliest. The shuttle's new launch date caused a scheduling conflict with NASA's moon-bound crater observation and sensing satellite, with the lunar mission being pushed back one day to June 18. It was unclear if Endeavour's second cancellation would again affect its launch. When Endeavour does head out from NASA's Kennedy Space Center in Florida, it will be the 32nd mission to the ISS, orbiting 350km above Earth, and the last of three missions to assemble the Japanese Kibo laboratory aboard the orbiting space station.