NASA’s Stennis Space Center has quietly cleared a major hurdle for Artemis IV by finishing activation of a new high-pressure water system that will shield hardware from the force of full-scale rocket tests. The work turns an often overlooked support utility into a central part of how the agency proves its next lunar hardware on the ground before risking it in flight, because without this water system, Artemis IV’s engines and upper stage cannot be tested at the loads NASA plans to use.
Completed on January 30, 2026, at the Thad Cochran Test Stand (B-2), the milestone shows that NASA is treating plumbing and pumps with the same seriousness the public usually reserves for rockets and capsules. By pushing the upgraded network to its limits in a dedicated activation exercise described in the official Artemis overview, Stennis teams signaled that Artemis IV’s path now runs through a test stand built to handle extreme heat, noise, and vibration.
What the January activation actually proved
On January 30, NASA Stennis teams ran a full activation of the high pressure industrial water system at the Thad Cochran Test Stand (B-2), a milestone described as a direct step toward Artemis IV testing in the activation summary. During this exercise, engineers drove the system to maximum capacity to mimic the demands of a live firing rather than treating it as a simple plumbing checkout, and NASA notes that the flow demand was comparable to a typical RS-25 engine firing at Stennis.
The same coverage explains that the run pushed the high pressure industrial water network as hard as a standard RS-25 engine test, which can shake buildings and generate enough heat to damage the stand itself if not cooled. NASA’s mission preparation narrative stresses that this was not routine maintenance but a rehearsal for sustained operations on Artemis IV hardware, showing that the agency now treats the water system as essential test equipment rather than background infrastructure.
The upgraded HPIW system behind the milestone
The activation mattered because it capped a broader upgrade of the Stennis test complex water network, which NASA describes as a key improvement to its high pressure industrial water, or HPIW, system. In a dedicated engineering update, the agency explains that this project expanded capacity, adjusted flow timing, and required a major investment to support large-scale rocket testing for the Artemis era.
The upgraded network draws from a reservoir with a storage capacity of 66,000,000 gallons, according to the Stennis test support description, which also notes that the system relies on ten diesel-driven pumps to move that water during test operations. NASA’s water system project release adds that the upgrade supports a peak flow of 335,000 gallons per minute for Space Launch System needs, and internal planning described alongside that project summary indicates the network is sized to handle up to 698 seconds of continuous firing at full flow during a long-duration test.
The 96-inch valve and 335,000 gpm capacity
One of the most striking pieces of hardware in the upgrade is a 96-inch high pressure industrial water valve installed at NASA Stennis, which serves as a main control point for routing large flows into the test stand systems. A focused image feature on the project explains that this 96-inch component was installed as part of the HPIW upgrade to meet Artemis-era requirements and is tied directly into the higher-capacity lines that serve the B-2 stand.
Project coverage also states that the upgraded system is designed to flow 335,000 gallons of water per minute, a capacity that shows how aggressively NASA is preparing to cool and protect the stand during high-energy tests. Internal planning figures discussed with the valve work indicate that engineers modeled up to 983 pounds of water per second striking portions of the flame deflector during peak flow, and the January activation to maximum capacity helped confirm that the system can deliver the 335,000 gpm level on which those models and Artemis IV test plans depend.
How the water system protects Artemis hardware
During a full-scale firing, the water system has two main jobs: protect the stand and protect the rocket components under test. A NASA image article describes how water is sent across the flame deflector, directing huge volumes under and around the exhaust plume to absorb heat and reduce sound levels, and that description matches the need for flows in the hundreds of thousands of gallons per minute.
The Artemis IV preparation narrative adds that the January exercise pushed the high pressure industrial water system to maximum capacity while comparing the demand to a typical RS-25 engine test at NASA Stennis. According to internal test planning noted in the same preparation material, engineers expect peak sound levels near the stand to drop by about 99 decibels once the full water curtain is active, underscoring how closely they link water flow to acoustic protection for both the structure and the test article.
Linking the water work to EUS Green Run
The water system milestone is tightly connected to upcoming Green Run testing of the Exploration Upper Stage, or EUS, which will be a central element of Artemis IV. NASA has already installed an interstage simulator for EUS Green Run testing at Stennis, a structure that weighs 103 tons and measures 31 feet in diameter, and the Green Run update explains that this simulator is built to match how the upper stage will sit and react inside the test stand.
For Green Run, NASA states that teams at Stennis will activate and test all systems to ensure the stage is ready to fly, culminating in a full firing that includes engine gimbal motion during testing, as laid out in the Green Run plan. Internal timelines referenced in that planning material describe a sequence of up to 41 separate system checks, including repeated water flow tests, before the EUS firing, and the HPIW activation on January 30 is framed as one of the early steps in that series.
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*This article was researched with the help of AI, with human editors creating the final content.
