NASA cancelled the scheduled launch of Artemis I again after the engineers could not overcome a hydrogen leak. After the second failed attempt, the US space agency decided not to try another launch in early September.
As per the current launch period due to the complex orbital mechanics, NASA was planning to launch Artemis I to the moon by September 6.
According to sources, there was a hydrogen leak in the quick disconnect - an interface between the liquid hydrogen fuel feed line and the Space Launch System (SLS) rocket. During the second launch, engineers detected a leak in a cavity between the ground side and rocket side plates surrounding an 8-inch line used to fill and drain liquid hydrogen. Three attempts at resealing it failed.
An official statement said that the teams will establish access to the area of the leak at Launch Pad 39B over the next few days. Officials said the rocket is safe but it is too early to tell whether the bump in pressurisation contributed to the cause of the leaky seal.
They will, in parallel, conduct a schedule assessment to provide additional data that will inform a decision on whether to perform work to replace a seal either at the pad, where it can be tested under cryogenic conditions or inside the Vehicle Assembly Building.
NASA is currently looking at a 25-day schedule to meet the requirement for the certification on the flight termination system. The space agency now will have to roll the rocket and spacecraft back to the vehicle assembly building to rest batteries.
After the uncrewed mission was scrubbed for a second time in a week, SpaceX CEO Elon Musk suggested that they use CH4(hydrogen) to combine high efficiency and ease of operation. "Delta-v difference between H2 and CH4 is small for most missions because the CH4 tank is much smaller & no insulation is needed," he said.