NASA’s latest attempt to fuel its giant moon rocket for a countdown test was thwarted by a dangerous hydrogen leak on April 14, the latest in a series of troublesome equipment troubles.
The launch team had just begun loading fuel into the rocket’s main stage when the leak surfaced. It was NASA’s third shot at a dress rehearsal, a necessary step ahead of a test flight to the Moon.
This time, the launch team managed to load some super-cold liquid hydrogen and oxygen into the main stage of the 30-story Space Launch System rocket, but fell short of the full amount. Liquid hydrogen is extremely dangerous, with officials noting that the system was checked for leaks prior to testing.
Technicians intentionally left the small upper stage empty after a faulty valve was discovered last week. The helium valve inside the upper stage cannot be replaced until the rocket is returned to its hangar at Kennedy Space Center.
The last two countdown attempts were sabotaged by balky fans and a large hand-operated valve that workers accidentally turned off on the pad last week.
Officials said via Twitter that they were assessing their next steps.
NASA was targeting June for the start of the launch of the 322-foot (98 m) SLS rocket. The empty Orion capsule on top will be sent on a four- to six-week mission to the Moon and back.
Astronauts will strap in for a second test flight around the Moon, which was planned for 2024. This will be followed by the first lunar landing by astronauts since 1972 in early 2025. NASA plans to announce the crew for these two missions this summer.