NASA Delays Artemis II Moon Mission to March After Fuel Test Issues

NASA has delayed the Artemis II mission launch to March at the earliest after running into hydrogen leaks during a key fueling test at Kennedy Space Center in Florida. The two-day wet dress rehearsal, which simulates loading fuel and counting down to launch, wrapped up early Tuesday morning when teams stopped at five minutes and 15 seconds before the simulated liftoff.

Background

The Artemis II mission marks NASA's first crewed flight to deep space in more than 50 years. Four astronauts will fly around the moon on a 10-day trip aboard the Orion spacecraft, launched by the massive Space Launch System rocket, or SLS. This mission comes after the uncrewed Artemis I test flight in 2022, which went well overall but showed areas for improvement.

Teams rolled the fully stacked SLS and Orion to Launch Complex 39B weeks ago to prepare for this wet dress rehearsal. The test loads the rocket with supercold liquid hydrogen and liquid oxygen, chills down systems, and practices the full countdown without lighting the engines. It helps spot problems before the real launch. NASA aimed for a February liftoff, with possible dates on February 8, 10, or 11. Cold weather earlier pushed back the test start by a few days, from late January plans to February 2.

The countdown kicked off Saturday evening at 8:13 p.m. EST, setting the clock at 48 hours and 40 minutes to a simulated launch at 9 p.m. EST on Monday. Over those days, ground crews filled the sound suppression water tank with more than 400,000 gallons, prepped the rocket for propellant, and powered up systems. Propellant loading for the core stage began around 48 hours out and ran for hours.

Key Details

The test faced hurdles from the start. Early on, engineers found high levels of liquid hydrogen in the tail service mast umbilical, a connection that feeds fuel to the rocket. They paused to monitor and fix the issue. Despite that, teams loaded over 733,000 gallons of propellant into the core stage and filled both the core and the upper interim cryogenic propulsion stage with liquid oxygen and hydrogen.

Hydrogen Leaks Halt Progress

Things smoothed out for a bit. At about five hours to simulated launch, crews resumed fast-filling liquid hydrogen into the core stage and started liquid oxygen in the upper stage. All cryogenic tanks shifted to replenish mode, holding fuel steady while teams checked valves and sensors. The countdown entered a 40-minute hold, a step added since Artemis I.

But trouble returned near the end. After reaching T-10 minutes, another hold came at T-5:15 due to a fresh liquid hydrogen leak at the tail service mast umbilical interface. NASA terminated the countdown there. Closeout teams had gone to the pad earlier for final checks, and they safely drained the propellants after.

"The countdown was terminated at the T-5:15 minute mark due to a liquid hydrogen leak at the interface of the tail service mast umbilical, which had experienced high concentrations of liquid hydrogen earlier in the countdown as well." – NASA statement

Teams met many goals, like full fueling and system chills, but not the full terminal count. NASA now plans a second wet dress rehearsal after data review.

The four astronauts—Reid Wiseman, Victor Glover, Jeremy Hansen, and Christina Koch—entered quarantine in Houston on January 21. With the February window closed, they got released and won't head to Florida as planned Tuesday. They'll quarantine again about two weeks before the new target date.

What This Means

Pushing to March closes the February launch window, which had just three days left. NASA will hold a news update Tuesday at noon EST to share findings and next steps. They must decide if the rocket stays at the pad or rolls back to the Vehicle Assembly Building for fixes. A rollback would add weeks or months.

This delay lets engineers dig into the leaks and other data. The tail service mast umbilical issue echoes problems from Artemis I, where similar leaks happened. Fixing it now avoids bigger troubles on launch day. Safety stays top priority, especially with humans aboard for the first time.

The wet dress rehearsal proved the fueling systems mostly work under real conditions. Loading that much supercold propellant without major spills shows progress. But repeating the test ensures reliability for the moon trip. Artemis II paves the way for Artemis III, which aims to land humans on the moon.

NASA's teams worked through cold weather, holds, and leaks over two days. They powered up the rocket, filled water tanks for sound suppression, chilled engines and lines starting 10 hours out, and got to within minutes of simulated liftoff. Draining happened smoothly afterward.

For the astronauts, the extra time means more training or rest before the next quarantine. Ground crews will scrub data for valve performance, sensor reads, and hydrogen levels. If all checks out after fixes, March could see a launch attempt. This step-by-step approach builds confidence in the SLS and Orion for deep space.