With Artemis II facing delays, NASA announces big structural changes to the lunar program

Throughout February 2026, people at the Kennedy Space Center got to witness an exciting sight: NASA’s behemoth Space Launch System rocket, SLS, standing on the launch pad, aimed toward the sky. The launch system has been key to the Artemis program – an ambitious series of missions intended to culminate in a sustained human presence on the Moon. NASA had initially planned to launch the second Artemis mission, which would take a crew of four people around the Moon, in February.

But as anticipation for launch built, an issue with the liquid propellant arose. A few days later, the SLS faced another problem, this time with the rocket’s upper stage, and had to roll back from the pad.

I’m an aerospace expert who is deeply passionate about aerospace technology and what it means for the U.S. and humanity’s future. I’ve been following the Artemis program’s timeline – February 2026 has represented a pivotal moment for U.S. spaceflight. Artemis II faced a number of delays, and NASA officials announced a shake-up of the larger program’s timeline.

Springing leaks

It started on Feb. 2, during Artemis II’s first wet dress rehearsal. During this major test, engineers assemble all components of the Space Launch System and fill its tanks with a combined 700,000 gallons of super-cold liquid hydrogen and liquid oxygen. These liquids act as the propellant for the rocket during launch.

During the test, the team detected a hydrogen leak at the interface of a 33‑foot-high (10 meters) service mast, the removable structure that brings the hydrogen and oxygen to the tank. They attributed the cause of the issue to moisture accumulated in the Teflon seal of two interfaces between that mast and the vehicle’s tank.

On the following day, NASA decided to postpone the launch until March 6. A new wet dress rehearsal would take place on Feb. 19 to verify everything was working as expected.

On the day of the second wet dress rehearsal, hydrogen operations proceeded smoothly, seemingly confirming plans for a March launch for Artemis II. Engineers at NASA likely breathed a sigh of relief, but they did so too early. A couple of days later another problem surfaced: They found the exploration upper stage was leaking helium. This upper stage of the rocket kicks in above 62 miles (100 kilometers), once the core stage expends all its propellant.

Because helium is essential for pressurizing cryogenic tanks and for purging the pipelines that will carry highly reactive liquid oxygen, the leak raised concerns.

Notably, these issues echoed the challenges SLS encountered ahead of its first launch for the Artemis I mission in 2022. Artemis I launched nearly six years after NASA’s original target date, ultimately accumulating 25 scrubbed or delayed launch attempts. Recurring hydrogen leaks in the tail service mast umbilical – a very similar issue – caused several of these delays.

Trouble with the SLS

On Feb. 25, the same day SLS rolled back to the vehicle assembly building for more work, NASA’s independent Aerospace Safety Advisory Panel released its annual report. This panel began in the aftermath of the January 1967 Apollo command module fire that claimed the lives of three astronauts, and NASA headquarters takes its assessments very seriously.

Citing the problems encountered on Artemis I and II, the panel warned of elevated risks for Artemis III, which planned to land on the Moon. They strongly recommended NASA restructure the program to reduce the likelihood of similar issues on future missions.

On Feb. 27, NASA made a major announcement: Artemis IV, scheduled for 2028, would now include a lunar landing. Artemis IV would then overlap with another landing planned in the same year, Artemis V.

NASA also confirmed that it plans to replace the exploration upper stage – the source of the helium leak – with a different upper stage known as the interim cryogenic propulsion stage. While the exploration upper stage was designed to use four engines, the interim cryogenic propulsion stage relies on a single engine.

The interim cryogenic propulsion stage previously flew on Artemis I, after which NASA intended to transition to the exploration upper stage for future missions. With the restructuring, however, the exploration upper stage program has been canceled, and NASA is returning to the interim cryogenic propulsion stage instead. With this change, Artemis appears to be going back to the basics and returning to simpler, proven hardware.

While Artemis II will not launch before April, the plan for the mission itself remains the same: It will still fly around the Moon.

But this new situation poses a question: If Artemis IV will now carry out the lunar landing, what will become of Artemis III, which had originally been planned as humanity’s return to the Moon? In essence, NASA is accelerating the schedule by adding more launches and tests before the first lunar landing attempt, and these changes are not necessarily to Artemis’ detriment.

A new timeline

NASA aims to increase the cadence of launches up to every 10 months starting in April 2026, incorporating fewer changes from mission to mission each time. This approach reduces technological uncertainty and stands in sharp contrast to the more than three‑year gap between the 2022 launch of Artemis I and the potential 2026 launch of Artemis II.

Artemis III will now become a tightly focused rehearsal mission lasting 30 days. NASA will test each mission component independently rather than checking them all together as a unit. Instead of visiting the Moon, Artemis III will remain closer to Earth.

NASA Administrator Jared Isaacman explained to CBS on Feb. 27 that Artemis III will launch the Orion spacecraft, which holds the astronaut crew, into low Earth orbit, where it will dock with one or both lunar landers – Blue Origin’s Blue Moon lander and SpaceX’s Human Landing System.

The Human Landing System will be a modified version of SpaceX’s Starship, the company’s enormous, superheavy spacecraft. The docking maneuver will help NASA confirm that the lander can handle the forces involved in connecting with Orion in space – essentially checking that the structure behaves as expected and can safely support the crew and their equipment.

Isaacman also pointed out that Artemis III may allow for NASA to test out the new spacesuit Axiom Space is designing for forays outside of the spacecraft.

The mission may also test navigation, communication, propulsion and life‑support systems. Interestingly, this series of tests aligns Artemis III more closely with the historical role of Apollo 7, which focused on evaluating the command and service module in Earth orbit.

In short, the new plans reshape Artemis III into a proof‑of‑concept mission intended to validate several critical systems before the two lunar landings planned for 2028 with Artemis IV and V. If successful, this approach should greatly improve the reliability of the missions that will finally return humans to the lunar surface. The revised timeline creates more opportunities to test and troubleshoot all the systems required for a safe landing.

It will also keep the missions more straightforward. With the same configuration across all missions, the tests will build on each other.

For now, you will need to wait a bit longer to watch humans walk in the Moon’s south pole region, where icy craters may hold clues to the early history of our solar system. But if February 2026 sets the tone, this next chapter will be anything but dull. Fasten your seat belts.

This article is republished from The Conversation, a nonprofit, independent news organization bringing you facts and trustworthy analysis to help you make sense of our complex world. It was written by: Marcos Fernandez Tous, University of North Dakota

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Marcos Fernandez Tous does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.