Late last week, NASA announced that it would perform a second hotfire test of the Space Launch System (SLS) core stage. While the decision will likely cause SLS to miss its launch date later this year, it will allow NASA and Boeing the opportunity to collect necessary data.
The initial hotfire test took place on January 16 and ended after just 67 seconds, falling short of the expected 485 seconds. A few days later, NASA claimed that the reason for the early shutdown was due to the hydraulic system on engine 2 hitting its set limits, triggering a shutdown by the flight computer.
Now, NASA is planning to run another static-fire test for the core stage’s four RS-25 engines “as early as the fourth week in February.” NASA had this to say on the viability of a second hotfire test:
“After evaluating data from the first hot fire and the prior seven Green Run tests, NASA and core stage lead contractor Boeing determined that a second, longer hot fire test should be conducted and would pose minimal risk to the Artemis I core stage while providing valuable data to help certify the core stage for flight.”
During the second test, engineers will update the control logic parameters that caused the first test to end early. According to NASA, the reason for this is because the initial parameters were very conservative. With this change, NASA believes that the upcoming test will last about four minutes, still short of the full 485-second goal but enough time for vital data to be collected.
NASA has yet to acknowledge if this second hotfire test will alter the scheduled Artemis 1 launch, but it will delay the core stage being delivered to KSC by over a month.