Engineers have completed the fifth of eight Green Run tests on the core stage of NASA’s new Space Launch System (SLS) rocket, continuing progress toward a hot fire test this fall. Operators evaluated the stage’s thrust vector control system on the historic B-2 Test Stand at NASA’s Stennis Space Center near Bay St. Louis, Miss., on Sept. 13. The test provided critical verification of the control system and its related hydraulics as operators moved the stage’s four RS-25 engines as they must move during flight to steer the rocket and maintain a proper trajectory. The stage now is set for two more tests – a simulated countdown demonstration and wet dress rehearsal – directly leading to the hot fire of all four RS-25 engines, as during an actual flight.
In the countdown demonstration, engineers will simulate the launch countdown and procedures to validate the established timeline and sequence of events. In the wet dress rehearsal, engineers will conduct another countdown exercise and actually load, control and drain more than 700,000 gallons of cryogenic propellants to ensure all is set for the final test of the Green Run series. The concluding test will activate all stage systems and fire the four RS-25 engines to generate the same combined 1.6 million pounds of thrust that will help launch the SLS rocket when it flies on the Artemis I mission.