NASA Tests for Artemis IV Milestone

On January 30, just before dawn, water started flowing through pipes the size of tiny subway tunnels in the pine country north of the Gulf Coast. At once, eleven pumps—ten diesel and one electric—came online and began to roar. The underground 96-inch line that connects NASA’s Stennis Space Center reservoir to the Thad Cochran Test Stand—the same stand that assisted in the Saturn V’s certification more than 50 years ago—saw a surge of 14 million gallons of water. No rocket engines were in operation. No flames. Only pressure, water, and a subdued sense of consequences.

For Artemis IV, the exercise was an official milestone. Teams from NASA Stennis were testing a recently installed cooling system that included water-cooled diffusers that served as heat shields, water-cooled fairings that directed exhaust, and a purge ring that shielded the flexible seal that allowed four engines to gimbal during a burn. It’s not glamorous at all. Everything must function. Under the 6,000-degree exhaust of the upper stage NASA has been getting ready to test—the four-RL10 Exploration Upper Stage built by Boeing at Michoud, just down the road in New Orleans—the steel flame deflector beneath the stand would warp in the absence of sufficient water flow.

What takes place at Stennis has a subtle impact. Because the test stands are loud enough to register on seismographs, the center is located in Mississippi swamp country and is surrounded by an acoustic buffer zone larger than some American cities. The astronauts on Apollo trained their ears to detect those noises. Engineers like Fred Haise, named for the Apollo 13 commander who grew up nearby, and Thad Cochran, named after the senator, talk about the stands almost like old friends. The water test in January took place on the B-2 side, which also housed the Space Shuttle’s primary propulsion test article ten years later and the Saturn V’s first stage in the 1960s. It is now being asked to host the next event.

This story is complicated by the fact that the “next” has been moving, which you wouldn’t know from the press release. Four weeks after the Stennis water test, on February 27, NASA revealed a comprehensive redesign of the Artemis architecture. The organization affirmed that it would re-target Artemis IV as the first crewed lunar landing for early 2028, standardize SLS, and incorporate a new Earth-orbit demonstration mission as Artemis III. A more awkward line was buried in the same release: the hardware Stennis had been getting ready to test, the Exploration Upper Stage, was no longer scheduled for use. Additionally, Mobile Launcher 2, which was delayed, would not be required. NASA claimed to be “assessing alternative options” for the second phase. Reading between the lines gives the impression that some of Mississippi’s work is currently searching for a purpose.

That isn’t necessarily tragic. Tests outlive missions. The B-2 has previously undergone retooling for Apollo, the Shuttle, the Delta IV Common Core Booster, and the Artemis I core stage. Someone, somewhere, will have to sit on that stand and burn it for a hot-fire run that mimics an actual launch, regardless of the final upper stage’s design. NASA refers to the test sequence as “Green Run,” which is basically a dress rehearsal. Every valve is cycled, every redline pressure is mapped, and every component is shaken violently enough to fail on the ground if it will fail at all. The timing of those valves and the pressure thresholds that the subsequent stage, whatever it may be, will be tested against will be determined by the 14 million gallons that flowed in late January.

It’s difficult to ignore how much of the Artemis narrative is told in this manner—in pumps and pipes and leisurely Mississippi mornings instead of the headline-grabbing launchpad antics. In April, the crew of Artemis II completed their lunar flyby, splashing down off San Diego after traveling close to 700,000 miles. The nation observed. The majority of people won’t watch an activation of the water system. However, Stennis project engineer Nick Nugent summed it up in a way that is probably harder to understand: “It is always good to give the system a good shake-down run before the real thing,” he said. The entire NASA plan for returning to the Moon can be summed up in that sentence. Everything that can be shaken should be shaken. Then give it another shake.

Honest program participants will tell you they have no idea if Artemis IV will launch in early 2028 as currently advertised. The architecture is still being worked on, and the schedule has previously fallen behind. However, the pumps are operating, the water at Stennis is flowing, and the old test stand is somehow still paying attention.