The hot fire test is back on. NASA announced it is targeting March 18 for the redo of the test to light up all four engines of the core stage that will be used on the Artemis I mission to the moon as soon as November this year.
Currently installed on a test stand at Stennis Space Center in Mississippi, NASA attempted a hot fire test on Jan. 16 that was supposed to last about eight minutes, simulating the actual flight that would happen when the Space Launch System carrying the Orion capsule launches from Kennedy Space Center. The test cut off though after 67.2 seconds.
That test was cut short when one of the engines exceeded some preset parameters while gimbaling, which means adjusting its angle slightly, and the computer system in place shut everything down. The planned retest was supposed to have happened already, but was delayed when NASA managers checking out the core stage systems found one of the eight valves that supply liquid oxygen and liquid hydrogen to the four RS-25 engines did not work as expected. All eight valves worked fine during the January test.
NASA announced the valve issue has been remedied, though, and now will try the hot fire test again. Later this week, NASA and prime core stage contractor Boeing will power up the core stage and see if all the parts check off ahead of next Thursday’s test. On March 16, NASA will power up the core stage and start the countdown clock for the hot fire. The exact time has yet to be announced.
NASA is performing the hot fire test again so they can prove out all the aspects of the simulated launch they want to test, to better ensure successful launch of Artemis I. That includes testing the vector control system, which means getting through the gimbaling of each engine by slight degrees to simulate adjustments that might be needed to ensure trajectory during an actual liftoff from KSC. It also wants to go through powering down the thrust and powering it back up to simulate the actual launch, and what needs to occur when the rocket reaches maximum dynamic pressure.
When that launch from Kennedy does occur, it will be come the most powerful rocket ever to launch from Earth. The core stage provides 1.6 million pounds of thrust to the Space Launch System. Combined with two side boosters from NASA partner Northrop Grumman, SLS will produce about 8.8 million pounds of thrust.
Artemis I will be an uncrewed mission to the moon, but actually traveling farther from Earth than any ship ever built for humans has ever flown before, about 280,000 miles away.
NASA’s SLS schedule still has Artemis I launching as early as November with Artemis II, a crewed mission around the moon without landing, by 2023 and then a 2024 flight that aims to put the first woman on the moon. Those targets, though, were part of the Trump administration’s push and could change under the new Biden administration.