A second launch attempt of the Space Launch System (SLS) rocket was scrubbed by the National Aeronautics and Space Administration (NASA) earlier today after teams struggled for hours to deal with yet another hydrogen leak on a quick disconnect arm. A similar leak plagued NASA’s first launch attempt this Monday, but the agency’s teams managed to find a workaround at the time, only to cancel the launch later on after an engine cooling test failed. This time around, NASA started its fuelling operations for the rocket early in the morning as it aimed at an early attempt to cool the engines. However, the agency’s attempts to fill the rocket failed after an initial overpressure led to the fuel filling system for the rocket to shut down.
NASA Stands Down For SLS Launch Attempt As Engineers Fail To Fix Another Hydrogen Leak
According to the early details, the launch teams recommended to the Artemis 1 launch director to call off the mission at roughly 11:00 AM ET today after they spent hours trying to fix a hydrogen leak that took place during the rocket’s fuelling. The SLS uses hundreds of thousands of gallons of liquid hydrogen to power its four engines, and NASA starts to fill the rocket’s massive tanks hours before launch in order to ensure that all systems are ready for a liftoff attempt. The hydrogen filling is also necessary to cool down the engines before liftoff, as the fuel, and its liquid oxygen oxidizer is stored at super cool temperatures - and flowing them into warm engines carries the risk of damaging them. 1:22 a, The first problem with today’s fuelling attempt surfaced early on during the loading as an overpressurization issue resulted in the loading system automatically stopping the fuel from flowing into the tanks. However, hydrogen loading resumed soon after the liquid oxygen started reflowing into the rocket, with a fast flow rate for the latter kicking off at roughly 6 AM ET. However, the pause in fuelling would continue to haunt the engineers later on as the change in temperature in the quick disconnect arm that is responsible for loading the rocket would cause it to develop another leak. This leak was detected at around 7:15 AM ET, and between then and the scrub that was officially called by the launch director at around 11:17 AM ET, engineers would continue to try to fix the system. These fixes involved waiting for the fuel flow to stop to let the quick disconnect arm warm up before trying again. The first attempt saw hydrogen start flowing back into the rocket at 8:00 AM ET, but proved to be insufficient as the leak surfaced once again. Engineers then tried restarting the system once again to give it another shot however this failed as well. Following this, they recommended to Ms. Blackwell-Thompson to call off today’s attempt, and after roughly half an hour of discussions, the launch director gave the go ahead for the scrub. The quick disconnect arms have been a thorny point for NASA for the Artemis 1 mission, and the arm involved today was not the same one that was behind the hydrogen leak on Monday. The leak took place around a cavity in the quick disconnect, and as opposed to Monday, teams decided to detank the vehicle immediately after the scrub was called.
