The dangers of hydrogen - and importance of robust and swift leak detection. According to Charlie Blackwell-Thompson, NASA’s Artemis launch director, teams encountered a liquid hydrogen leak while loading the propellant into the rocket’s core stage, and multiple troubleshooting efforts to address the area of the leak by reseating a seal in the quick disconnect where liquid hydrogen is fed into the rocket did not fix the issue. A Nasa statement reads, “A liquid hydrogen leak has reoccurred again in a cavity between the ground and flight side plates of a quick disconnect in the engine section.” While it can’t be said definitively what caused the leak, attention is focusing on inadvertent over-pressurisation of the hydrogen line early morning, and incorrect commands to the wrong valve, according to reports. Engineers attempted to flush helium through the line but without success. Escaping hydrogen exceeded flammability limits by around two or three times. Dangers to life from hydrogen-related incidents include asphyxiation, blast overpressure, burns, fragments, frostbite and hypothermia. Liquid hydrogen fuel has many benefits, including its low molecular weight and high energy output when burned together with liquid oxygen, according to WHA. Liquid fuels are often a popular choice for secondary/upper rocket stages after solid rocket fuels provide the extra thrust required for liftoff. Hydrogen also provides low-density liquid fuel for navigation thrusters in orbit.

Posted by Rafał Frączek at 2022-09-22 07:40:49 UTC