NASA determines cause of SLS rocket shutdown

20 Jan 2021

Hot fire test of SLS rocket core stage. Image: © Robert Markowitz/NASA

The SLS rocket test was due to run for around eight minutes but suffered an engine shutdown after just 67 seconds.

On Saturday (16 January), NASA conducted a ‘hot fire’ test for the Space Launch System (SLS) rocket.

During the test, the engines were due to run for around eight minutes, which would be the duration they would fire during a moon mission. However, the engines inexplicably shut down after a little more than one minute.

After analysing the data from the test, NASA has determined the cause of the early shutdown, saying that the problem was not with the engines or other hardware.

In an update, agency officials said the shutdown was “triggered by test parameters that were intentionally conservative to ensure the safety of the core stage during the test”.

The hot fire is the final test of the Green Run test series, a comprehensive assessment of the SLS’s core stage prior to launching the Artemis 1 moon mission.

The SLS is a major component of NASA’s Artemis programme, which aims to land two astronauts near the lunar south pole in 2024.

The core that was tested on Saturday will launch the Artemis 1 mission, an uncrewed test flight of the agency’s Orion capsule around the moon. It is currently scheduled to lift off in late 2021.

NASA said that all four engines performed as expected throughout the hot fire test. “While the test planned to fire the four engines for about eight minutes, the team still achieved several objectives during the shorter firing,” the space agency said in its update.

“They repeated the wet dress rehearsal, once again filling the tanks with more than 700,000 gallons of propellant with some added modifications to procedures to ensure proper thermal conditioning of the engines. They successfully pressurised the propellant tanks, completed the countdown, and ignited the engines for the first time. The engines reached their full power of 109pc producing 1.6m pounds of thrust, just as they will during the Artemis 1 launch.”

According to NASA, the core also generated a major component failure reading during the test. While the SLS team will continue to investigate that reading, officials said it did not contribute to the shutdown. The team is yet to determine if a second hot fire test is required.

Jenny Darmody is the editor of Silicon Republic