in Early September, Reviewing Options
After standing down on today’s Artemis I launch attempt when engineers could not overcome a hydrogen leak in a quick disconnect, an interface between the liquid hydrogen fuel feed line and the Space Launch System (SLS) rocket, mission managers met and decided they will forego additional launch attempts in early September.
Over the next several days, teams will establish access to the area of the leak at Launch Pad 39B, and 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.
To meet the requirement by the Eastern Range for the certification on the flight termination system, currently set at 25 days, NASA will need to roll the rocket and spacecraft back to the VAB before the next launch attempt to reset the system’s batteries. The flight termination system is required on all rockets to protect public safety.
During today’s launch attempt, engineers saw 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 from the SLS rocket. Three attempts at reseating the seal were unsuccessful. While in an early phase of hydrogen loading operations called chilldown, when launch controllers cool down the lines and propulsion system prior to flowing super cold liquid hydrogen into the rocket’s tank at minus 423 degrees F, an inadvertent command was sent that temporarily raised the pressure in the system. While the rocket remained safe and it is too early to tell whether the bump in pressurization contributed to the cause of the leaky seal, engineers are examining the issue.
Because of the complex orbital mechanics involved in launching to the Moon, NASA would have had to launch Artemis I by Tuesday, Sept. 6 as part of the current launch period. View a list of launch windows here.
Author Rachel Kraft
The launch director waived off today’s Artemis I launch attempt at approximately 11:17 a.m. EDT. Teams encountered a liquid hydrogen leak while loading the propellant into the core stage of the Space Launch System rocket. 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. Engineers are continuing to gather additional data. Author Rachel KraftPosted on
After the third troubleshooting attempt, the liquid hydrogen leak has occurred again. Teams are discussing next steps. Author Rachel KraftPosted on
After warming up the area of the liquid hydrogen leak, engineers are once again flowing liquid hydrogen to the core stage. Author Rachel KraftPosted on
Engineers are continuing troubleshooting efforts to address a liquid hydrogen leak in a cavity in the quick disconnect where the flight side and ground side plates join. They once again will attempt to warm up the quick disconnect to try to reset the seal.
The liquid oxygen tank of the core stage is full and is being replenished as some of the super cooled propellant boils off. Author Rachel KraftPosted on
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. Teams are discussing additional troubleshooting efforts. Author Rachel KraftPosted on
Launch controllers have started flowing liquid hydrogen to the core stage again after troubleshooting the reoccurrence of a leak. This time engineers attempted to reseat the seal in a quick disconnect cavity where the leak occurred by applying pressure to it with helium. Author Rachel KraftPosted on
As engineers increased the pressure on the flow of liquid hydrogen into the core stage, a leak reoccurred. Engineers will attempt to reseat the seal in the quick disconnect cavity where the leak has been detected. This time they will stop flowing liquid hydrogen to the tank, close the valve used to fill and drain it, then increase pressure on a ground transfer line using helium to to try to reseal it.
Launch controllers are continuing to flow liquid oxygen to the core stage. Author Rachel KraftPosted on
Launch controllers have resumed flow of liquid hydrogen to the core stage after warming up a quick disconnect in the engine section where a hydrogen leak was detected in the cavity between the ground and flight side plates of the quick disconnect. Teams warmed up the quick disconnect to attempt to reseat it and set a proper seal. Author Rachel KraftPosted on
Engineers detected a liquid hydrogen leak in a quick disconnect cavity and have stopped flowing the propellant to the core stage while they troubleshoot. Launch controllers are attempting to warm up the quick disconnect to attempt to reseat it to get a tight seal. Liquid oxygen flow is continuing.