NASA has once again scrubbed the debut launch of its Space Launch System (or SLS) rocket after engineers failed to fix a persistent hydrogen leak.
The hydrogen leak was first noticed this morning, soon after the rocket began being fueled with liquid hydrogen. NASA said the leak “developed in the supply side of the 8-inch quick disconnect while attempting to transfer fuel to the rocket.” The team made three troubleshooting attempts, but a leak was detected after each effort to fix the problem. After the third time, engineers recommended that the launch be a ‘no go.’ Soon after, the mission’s launch director, Charlie Blackwell-Thompson, decided to scrub the launch attempt.
The SLS is meant to be one of the workhorses of NASA’s Artemis program. For this mission, called Artemis I, it is tasked with launching the uncrewed Orion crew capsule around the Moon. On future missions, NASA will attempt to return astronauts to the lunar surface using SLS, Orion, and additional equipment.
The agency also scrubbed the previous launch attempt of the SLS, which was supposed to happen on August 29th, citing issues with the engine bleed system meant to help the engines get to a proper temperature before takeoff. A hydrogen leak was also detected during that launch attempt.
NASA has another launch window left — from 5:12 PM to 6:42 PM on September 5th — before it faces a major delay. The flight termination system that’s meant to keep the rocket from becoming a dangerous missile if something goes very wrong during launch needs to be re-tested relatively frequently (it’s supposed to be every 20 days, but NASA got that extended to 25 days), and that testing can’t be done on the launch pad.
Given that the rocket rolled out to the launchpad on August 16th, NASA’s time will pretty much be up after September 5th. If the SLS doesn’t launch then, it’ll have to be rolled back to NASA’s Vehicle Assembly Building where the termination system can be re-tested. That’ll take time, potentially pushing this launch back to late October at the earliest.
If that launch is successful though, it should pave the way for a mission next year where NASA sends a crew up in the Orion capsule for the first time. They’ll just be flying around the moon, not landing on it — that milestone is planned for 2025, when we’ll hopefully see the first woman walk on the moon.