CAPE CANAVERAL, Fla. - NASA's new moon rocket sprang another dangerous fuel leak Saturday, forcing launch controllers to call off their second attempt to send a crew capsule into lunar orbit with test dummies.
The first attempt earlier in the week was also marred by escaping hydrogen, but those leaks were elsewhere on the 322-foot rocket, the most powerful ever built by NASA.
Launch director Charlie Blackwell-Thompson and her team tried to plug Saturday's leak the way they did the last time: stopping and restarting the flow of super-cold liquid hydrogen in hopes of removing the gap around a seal in the supply line. They tried that twice, in fact, and also flushed helium through the line. But the leak persisted.
Blackwell-Thompson finally halted the countdown after three to four hours of futile effort.