NASA's SLS rocket will go through a second and longer hot fire test

Mariella Moon
·Associate Editor
·2 min read

NASA will conduct a second hot fire test for the Space Launch System’s rocket core stage as early as the fourth week of February. It will be part of the rocket’s Green Run series of tests meant to assess the core stage and ensure it’s ready for the Artemis I mission, which will send an unmanned Orion spacecraft to the Moon. The rocket’s first ever hot fire test in mid—January, wherein all four of its RS-25 engines fired simultaneously, was cut short due to a problem with its hydraulic system. What was supposed to be an eight-minute burn lasted for only 67 seconds — NASA wants the second go to last longer than that to be able to collect more data.

The agency set an eight-minute goal for the second test, as well, since that’s how long it would take to send the rocket to space. According to NASA’s announcement, though, the Green Run team analyzed data from the first test firing and determined that four minutes would be enough to provide significant data that can help verify if the core stage truly is ready for flight. “Conducting a second hot fire test will allow the team to repeat operations from the first hot fire test and obtain data on how the core stage and the engines perform over a longer period that simulates more activities during the rocket’s launch and ascent,” NASA wrote.

To prepare for the second test, the Green Run team is analyzing data from the first one and drying and refurbishing the SLS engines. It will then take a month to refurbish the core stage and its engines after the second test before they can be shipped to NASA’s Kennedy Space Center in Florida for the Artemis I launch expected to happen later this year. It remains to be seen whether that timeline will be met when the Artemis program’s manned Moon landing probably won’t happen in 2024 like the previous administration had announced.