The core stage of NASA’s Space Launch System (SLS) rocket was the focus of a recent hot fire test conducted at the agency’s Stennis Space Center in Mississippi. This largest rocket component constructed by NASA fired its four RS-25 engines successfully for 8 minutes and 19 seconds and generated more than 1.6 million pounds of thrust within seven seconds.

The SLS is a key component of NASA's Artemis program, which is planned to establish a permanent human presence on the moon. During this last phase of the eight-part Green Run test campaign, the Boeing-built stage fed liquid hydrogen and liquid oxygen into four RS-25 engines built by Aerojet Rocketdyne. In an actual mission launch, the system is expected to deliver 2.2 million pounds of thrust.

The two propellant tanks in the SLS core stage collectively contain more than 733,000 gallons of super cold liquid hydrogen and liquid oxygen to help fuel the RS-25 engines at the bottom of the stage. Prior tests in the Green Run test series evaluated the integrated functionality and performance of the core stage’s avionics systems, propulsion systems, and hydraulic systems.

After it is refurbished, the SLS core stage will be shipped to NASA’s Kennedy Space Center in Florida and assembled with the solid rocket boosters in preparation for Artemis I.

On March 18, 2021, the four RS-25 engines fired for the full-duration of 8 minutes during the test and generated 1.6 million pounds of thrust. Source: NASA/Robert Markowitz