Artemis 2 Launch Date Slips to March as NASA's Three-Year 'Fix' Failed to Stop Rocket Leaks

NASA's ambitious return to the lunar surface has hit a significant snag as persistent technical troubles continue to plague the SLS rocket. Despite 36 months of dedicated troubleshooting, the agency was unable to resolve the critical hardware flaws that threatened the next phase of the program.

This latest setback pushes the highly anticipated crewed launch further into the future, leaving the timeline for lunar exploration in flux.

NASA had to terminate a vital propellant trial for the massive Artemis 2 booster during the early morning on Tuesday, which postponed the crewed lunar flight by four weeks or more. As the sun rises over the towering orange craft, researchers are working to explain the precise nature of the malfunction—though much of their preliminary data echoes previous setbacks.

The 'Wet Dress Rehearsal' Challenge

The propellant assessment for the Artemis 2 Space Launch System (SLS) booster started on Saturday night (31 Jan) and lasted until Tuesday. Known as a 'wet dress rehearsal', this procedure subjects the SLS ship and surface crews to an artificial timer to energise the craft and fill it with over 700,000 gallons of freezing liquid oxygen and hydrogen required for liftoff.

Filling activities began without issue on 2 February when flight directors signalled to commence work, but hydrogen leaks at the rear supply connection on the mobile base forced engineers to adopt a repair mindset for most of that day.

This problem likely rings a bell, as the Artemis 1 SLS suffered hydrogen leaks at this exact spot during its own countdown trial three seasons back. Those faults forced the rocket to return to the massive Vehicle Assembly Building (VAB) on three distinct occasions throughout a half-year period before the craft eventually took flight.

Notably, Artemis 1 departed in November 2022, sending an empty Orion capsule on a four-week journey to circle the moon and return home.

Preparing for a Crewed Leap

For the Artemis 2 project, the agency intends to evaluate how well Orion supports a crew in the deep space environment. NASA's Reid Wiseman, Victor Glover and Christina Koch, alongside Jeremy Hansen from Canada, are set to occupy the capsule for a ten-day trek behind the moon. This voyage will certify the ship's technology for Artemis 3, which is currently being designed to return humans to the dusty lunar ground.

'We really did learn a lot from the Artemis 1 mission, and we implemented a lot of the lessons learned yesterday through wet dress,' Lori Glaze, NASA's Exploration Systems Development Mission Directorate acting associate administrator, said during a post-wet dress rehearsal press conference on Tuesday.

'Everyone's aware of some of the challenges with the hydrogen tanking from Artemis 1, and we've made some changes,' she added. It is worth noting, though, that the Artemis 2 countdown simulation proceeded much more efficiently than the initial propellant assessment for Artemis 1.

Terminal Count and the T-5 Halt

Despite spending hours addressing the stubborn hydrogen leak — which agency leaders noted had been brought under control but not fully stopped — mission operators successfully loaded both SLS tiers and reached the terminal count phase (the final ten minutes before flight). However, the group failed to meet the specific mark near T-0 required to secure NASA's official certification to carry a human crew.

'The fact that we got to full tanking yesterday on the first try was a tremendous success, and we gathered an enormous amount of data in the processes and how we want to go forward with that in the future,' Glaze said.

At the T-5 minute 15-second mark, the SLS automated firing system halted the timer because of a surge in the very same quick-disconnect hydrogen leak that had caused trouble all day, prompting a total cancellation of the trial, the agency reported.

'As we began that pressurisation, we did see that the leak within the cavity came up pretty quick,' Artemis Launch Director Charlie Blackwell-Thompson said during Tuesday's press briefing, noting a specific hollow space on the rocket's supply line. This event set off existing safety protocols designed for such emergencies, she noted.

'We got into our safety steps. We saw the hydrogen concentration come down and then later in the evening, we got into our drain operation,' she said.

Assessing the 'Bespoke' Hardware

While the agency insisted the wet dress rehearsal was a general triumph due to the collected data and the feat of topping off the SLS tanks on the first attempt, Blackwell-Thompson also provided reassurance. She noted that, unlike the situation with Artemis 1, these hydrogen issues can likely be fixed at the pad and do not appear to require a return to the VAB for repairs.

'During Artemis 1, we found out that we can do some work on these plates at the pad,' Blackwell-Thompson said. 'I had hoped that we would not have to demonstrate that again for Artemis 2, but we showed that we can go do this work at the pad and be ready for launch.'

Regarding the SLS's continued hydrogen leaks after a three-year gap, agency leaders have several hypotheses but have not yet identified a definitive cause. 'These are very bespoke components,' NASA Associate Administrator Amit Kshatriya remarked on Tuesday, characterising every SLS as a distinct machine that requires its own period of study and familiarity.

Kshatriya suggested that the faulty seal might have been caused by tremors experienced during the booster's first journey to the launch site. Last month, the Artemis 2 SLS spent almost twelve hours travelling the four miles from the VAB to the pad, moving at a maximum pace of just one mile per hour.

'That rollout environment is very complicated,' he added, mentioning that the Artemis 1 SLS underwent various vibration assessments during its journey to Launch Complex-39B to better understand how those forces impact the craft and its base. 'We think that's a contributor. But again, we have to tear the seal apart and see what happened.'

'This is the first time this particular machine has borne witness to cryogens. And how it breathes, and how it vents, and how it wants to leak is something we have to characterise,' Kshatriya noted, adding that ground evaluations can only simulate so much before a real trial is required.

The Complexity of Cryogenics

Despite taking a firm stance on managing hydrogen escapes during the previous mission, 'we're pretty limited as to how much realism we can put into the test,' stated John Honeycutt, head of NASA's Artemis Mission Management team.

'We try to test like we fly, but this interface is a very complex interface, and when you're dealing with hydrogen, it's a small molecule, it's highly energetic,' he remarked, conceding that he and his colleagues did not anticipate these problems resurfacing.

'This one caught us off guard,' Honeycutt continued. 'The initial things that we were seeing in the technical team felt like we either had some sort of misalignment or some sort of deformation or debris on the seal.'

Shifting to a March Window

According to Space.com, the agency must assess the booster and surface equipment at the site before setting a new time for a second countdown trial; consequently, it has decided to skip the February flight window. Had the previous test been a total success, that departure period would have taken place between 8 and 11 February.

'With more than three years between SLS launches, we fully anticipated encountering challenges,' NASA Administrator Jared Isaacman said in a post on X early Tuesday. 'That is precisely why we conduct a wet dress rehearsal. These tests are designed to surface issues before flight and set up launch day with the highest probability of success.'

Mission managers are now targeting the following month's window, which is available from 6-9 March and on 11 March, with roughly five days of opportunity around the start of each subsequent month.