A major milestone was completed this week in Huntsville as NASA and Boeing continue preparations for the historic Artemis program.

Boeing and NASA engineers at Marshall Space Flight Center on Wednesday completed the structural test campaign for the Space Launch System (SLS), which is the most powerful rocket in world history scheduled to power Americans back to the Moon in 2024; the mission will include landing the first woman ever on the lunar surface.

SLS is part of NASA’s new backbone for deep space exploration, along with the Orion spacecraft and the Gateway in orbit around the Moon. Indeed, it is the only rocket that can send Orion, astronauts and supplies to the Moon in a single mission.

Alabama’s aerospace industry has led the effort to build the SLS, which stands 212 feet high and 27.6 feet in diameter.

Boeing is the core stage lead contractor, and Aerojet Rocketdyne is the RS-25 engines lead contractor. The SLS program is managed out of Marshall Space Flight Center, while Boeing’s Huntsville-based Space and Launch division manages the company’s SLS work.

The structural test campaign concluded this week was the largest test campaign conducted at Marshall since the test program for the Space Shuttle more than 30 years ago, according to NASA.

“The Space Launch System and Marshall test team have done a tremendous job of accomplishing this test program, marking a major milestone not only for the SLS Program but also for the Artemis program,” stated John Honeycutt, SLS program manager. “From building the test stands, support equipment and test articles to conducting the tests and analyzing the data, it is remarkable work that will help send astronauts to the Moon.”

During the SLS structural test campaign, five structural test articles underwent 199 separate test cases, and more than 421 gigabytes of data were collected to add to computer models used to design the incredible rocket. The final test marks the achievement of all SLS structural testing requirements prior to the Artemis I mission — the first in a series of increasingly complex missions that will enable human exploration to the Moon — and, eventually, Mars.

For the final test, the liquid oxygen tank test article — measuring 70 feet tall and 28 feet in diameter — was reportedly bolted into a massive 185,000-pound steel ring at the base of Marshall’s Test Stand 4697. Hydraulic cylinders were then calibrated and positioned all along the tank to apply millions of pounds of crippling force from all sides while engineers measured and recorded the effects of the launch and flight forces. The liquid oxygen tank circumferentially failed in the weld location as engineers predicted and at the approximate load levels expected, proving flight readiness and providing critical data for the tank’s designers. Per NASA, this final test to failure on the LOX STA met all the program milestones.

The Marshall team in Huntsville has been conducting structural qualification testing on the SLS since May 2017. Tests have included an integrated test of the upper part of the rocket stacked together — including the interim cryogenic propulsion stage, the Orion stage adapter and the launch vehicle stage adapter. That was followed by testing of the four largest structures that compose the core stage: the engine section, the intertank, the liquid hydrogen tank and the liquid oxygen tank. According to NASA, each of these tests provided additional data to computer models that predict how the structures will perform under the harsh conditions of launch and flight.

“The Marshall test lab team has worked closely with the Space Launch System Program to test the rocket’s structures from the top to bottom,” said Ralph Carruth, Marshall’s test lab director. “After watching the test stands being built, working alongside SLS and Boeing engineers to establish testing procedures and conducting and gathering results of five structural qualifying tests, we are proud to contribute data shows these structures can withstand the rigors of flight.”

With the conclusion of testing, designers now have data that may be helpful in optimizing SLS hardware. Testing the new, complex pieces of hardware is critical to the success not only of the first flight test of SLS and Orion but also to all future missions.

“This year is a landmark year for core stage testing for the Artemis missions,” explained Julie Bassler, SLS stages manager. “We have successfully completed our core stage major structural tests at Marshall Space Flight Center and are making progress on Green Run testing of the Artemis I core stage at Stennis Space Center that will simulate launch. All these tests are not only valuable for the first Artemis mission but also validates the new integrated design of the SLS core stage structure, propulsion and avionics systems and ensures its readiness for future flights.”

Sean Ross is the editor of Yellowhammer News. You can follow him on Twitter @sean_yhn