As early as Jan. 17, 2021, NASA is planning the final test of the Green Run sequence, the hot fire.
The hot burn is the culmination of the Green Run test series, an eight-part test campaign that will eventually bring the Space Launch System (SLS) core stage – the space rocket that will fuel the agency’s next generation of manned lunar missions – to life for the first time.
NASA performed the seventh test of the Green Run test sequence of the SLS core stage – the wet rehearsal – at NASA’s Stennis Space Center near Bay St. Louis, Mississippi on Dec. 20, 2020, marking the first time the cryogenic or super-cold liquid propellant was fully loaded into and drained from the two giant tanks of the SLS core stage.
The dress rehearsal provided structural and environmental details, tested the cryogenic storage capabilities of the stage, demonstrated the software with the flight computers and avionics of the stage, and conducted functional tests of all the systems of the stage.
Since a valve did not close correctly, the end of the test was automatically stopped several minutes early. Subsequent data analysis showed that the expected closure of the valve was off by a fraction of a second and that the hardware, software and stage controls were all working properly to complete the test.
The team has corrected the timing and is able to continue with the Green Run series’ final test.
“During our green run test at the dress rehearsal, the core stage, stage control and green run software functioned properly, and there were no leaks when the tanks were fully loaded and refilled for about two hours,” said Julie Bassler, SLS stage manager at NASA’s Marshall Space Flight Center in Huntsville, Alabama. “The data from all the tests so far have given us the confidence to proceed with the hot fire.”
All four RS-25 stage engines will simultaneously be fired for up to eight minutes during the upcoming hot fire test to simulate the efficiency of the core process during launch.
The core stage will be refurbished for SLS after launch at Stennis and transported on the agency’s Pegasus barge to NASA’s Kennedy Space Center in Florida.
In preparation for Artemis I, the first combined flight of SLS and Orion and the first mission of the agency’s Artemis program, the stage will then be assembled with the other pieces of the rocket and NASA’s Orion spacecraft.
“The next few days are critical in preparing the Artemis I rocket stage, the B-2 test stand at NASA’s Stennis Space Center and the test team for the finale of the Green Run test series,”The next few days are critical in preparing the Artemis I rocket stage, the B-2 test stand at NASA’s Stennis Space Center and the test team for the Green Run test series finale. “The upcoming Green Run hot fire test is the culmination of a lot of hard work by this team as we approach a major milestone for NASA’s Artemis missions.”
A joint project between NASA and its industry partners is the test of the SLS rocket’s core stage.
For the core point, Boeing is the prime contractor and for the RS-25 engines, Aerojet Rocketdyne is the prime contractor. Under the Green Run Test Sequence, prior testing evaluated the avionics systems, propulsion systems and hydraulic systems of the point.
NASA is preparing to land the first woman on the moon by 2024 and the next man. SLS and Orion form NASA’s backbone for space exploration, along with the human landing system and lunar orbit gateway. SLS is the only rocket capable of carrying one single mission to Orion, astronauts and supplies to the Moon.