NASA's next-generation rocket for Artemis' mission to the moon, the Space Launch System (SLS), has been through some problems. The project is moving forward, however, and NASA has announced it has reached a milestone for firing the engines in the first “hot fire” test.
The SLS missile core stage is currently undergoing a series of tests called the Green Run, which tests all of the hardware that makes up the stage. This includes testing the flight computers, fuel tanks, propulsion systems, and more.
In total, Green Run consists of eight tests, including loading the fuel tanks for the first time, checking the supply systems that deliver the propellant to the tanks, igniting all four engines in the stage for the first time, and restoring the environment around the start with respect to vibration and temperature the hardware to be tested withstood the tough starting conditions.
The Space Launch System (SLS) rocket is completing the Green Run test for the core stage of the rocket installed in the upper left of the B-2 test stand at NASA's Stennis Space Center near Bay St. Louis, Mississippi. For Green Run, the team runs a series of eight tests, culminating in Test 8, a full hot-fire test that lasts eight minutes. The flames from the test emerge from the yellow flame bucket, which is shown here on the north side of the test bench. The B-2 test stand has two positions and the right side of the test stand is used for other tests. The SLS core stage will be tested for the first time before being used on the Artemis I lunar mission. NASA / Stennis
The first four of these eight tests have now been completed. The final test was checking the propulsion system components connected to the motors to make sure nothing was leaking and everything was working as intended. Instead of using actual rocket fuel for this test, NASA engineers used nitrogen and helium gases and pushed them through the system over a period of three weeks to check for leaks.
"With test gases flowing through these many parts of a complex rocket stage, we expected the test team to encounter some problems," said Jonathan Looser, who manages the main propulsion system of the SLS core stage, in a statement.
"In the past, there has never been a human-rated NASA launcher that was flown without one or more full tests before flight, and everyone encountered problems the first time. As expected, we found some with valves and seals and addressed, and now we are ready to complete the next four Green Run tests. "
The tests will be conducted at NASA's Stennis Space Center near Bay St. Louis, Mississippi, where staff are preparing for the next test, which will culminate in a full fire of the four engines in the "hot fire" test before that the stage will be sent to the Kennedy Space Center in Florida.