The core stage of NASA's Space Launch System (SLS) rocket fired all four of its RS-25 engines for a little more than eight minutes—about the same duration needed to launch the Artemis I mission to the Moon. The successful hot fire tested the engines' ability to direct thrust as well as handle throttling up to 109% power. Two massive propellant tanks that hold more than 733,000 gallons of liquid hydrogen and liquid oxygen fed the burning engines at the bottom of the stage. According to Stennis Center Director Richard Gilbrech, "This final test in the Green Run series represents a major milestone for this nation's return to the Moon and eventual mission to Mars."