The first attempt earlier in the week was also marred by a hydrogen leak, but those leaks were elsewhere on the 98-meter-long rocket, the most powerful ever built by NASA. Launch manager Charlie Blackwell-Thompson and her team tried to plug Saturday’s leak the same way they did last time: stopping and restarting the flow of super-cold liquid hydrogen in hopes of removing the void around a seal in the line provision. They tried it twice, actually, and also shot helium through the line. But the leak continued. Blackwell-Thompson finally stopped the countdown after three to four hours of futile effort. More than 400,000 people have gathered on Florida’s Space Coast for the launch, according to the Orlando Sentinel newspaper.
