NASA Struggles With Familiar Problem on Artemis I: A Hydrogen Leak

The leak that delayed NASA’s latest attempt to blast off its moon rocket over the weekend was tied to the agency’s use of liquid hydrogen, a fuel some space companies have chosen not to use as they develop new engines for their own large rockets.

Hydrogen is light and burns extremely hot, making it an efficient propellant to use on different stages of a rocket launch, the National Aeronautics and Space Administration has said.