NASA Faces New Setback in Moon Rocket Fuel Test for Artemis II

NASA ran into fresh trouble while trying to fix fueling problems on its giant Space Launch System rocket at Kennedy Space Center in Florida. The test last Thursday aimed to check new seals but saw reduced hydrogen flow from ground gear. This comes after leaks stopped the first full dress rehearsal on February 3, pushing the Artemis II crewed moon flyby to no earlier than March 6.

Background

The Space Launch System, or SLS, is NASA's heavy-lift rocket built to send astronauts back toward the moon. Artemis II marks the first crewed flight of this program. Four astronauts—Reid Wiseman, Victor Glover, and Christina Koch from NASA, plus Jeremy Hansen from the Canadian Space Agency—plan to loop around the moon without landing.

Teams stacked the rocket on Launch Pad 39B late last year. They have run through countdown drills to mimic launch day. The wet dress rehearsal, or WDR, fills the rocket with over 700,000 gallons of super-cold liquid hydrogen and liquid oxygen. This chills the systems and checks for leaks before real fuel-up on launch day.

The first WDR started January 31 and wrapped up early February 3. Cold weather slowed things down at the start. Then, as teams shifted from slow to fast hydrogen fill on the core stage, leaks appeared. Hydrogen is tricky—it burns fast if it builds up in the air. Rules limit it to 16% concentration. During tank pressurizing near the end, levels went over that. The countdown stopped at T-minus 5 minutes and 15 seconds.

Charlie Blackwell-Thompson, the launch director, said after that test they wanted to hit a three-minute hold in launch-ready state, recycle the clock for a new countdown, and hand off to automated systems. Those steps did not happen.

Cold also hit cameras and gear, plus audio dropouts plagued ground teams. A valve on the Orion crew capsule needed tightening, and closeout work by a five-person team took extra time. Still, they filled all tanks in the core stage and upper interim cryogenic propulsion stage.

Key Details

After the first WDR, NASA paused to fix seals in the Tail Service Mast Umbilical, the spot that feeds hydrogen to the core stage. On February 12, they ran a shorter "confidence test." Teams pumped in some liquid hydrogen to test those fixes. Leak rates dropped a lot from before.

But ground equipment cut the hydrogen flow. Engineers suspect a clogged filter. Over the weekend, they swapped it out and reconnected lines. Now, data looks good enough for a second full WDR.

Second Wet Dress Rehearsal Plan

The new test kicks off Tuesday, February 17, at 6:40 p.m. EST from Firing Room 1. Tanking hits Thursday, February 19, aiming for a fake launch at 8:30 p.m. EST in a four-hour window. Controllers plan to count down to T-minus 1 minute 30 seconds, hold three minutes, go to T-minus 33 seconds, pause, then recycle to T-minus 10 minutes and run it again.

A closeout crew will practice launch pad tasks, like prepping Orion, even without astronauts there. NASA added this step back in after skipping it at first.

"The confidence test related to the seals we repaired and replaced after WDR-1 provided a great deal of data, and we observed materially lower leak rates compared to prior observations during WDR-1," said NASA Administrator Jared Isaacman.

Isaacman added they got enough info and did not need to troubleshoot more right then.

Blackwell-Thompson noted they waived a second terminal count try during WDR-1 due to earlier fueling snags.

What This Means

These tests build confidence in the rocket before astronauts climb aboard. No firm launch date sets until WDR-2 succeeds. March 6 stays the earliest shot in the March window. A February launch is off the table, so the crew left quarantine in Houston and won't head to Florida this week. They will quarantine again two weeks before the next try.

Each issue gets a fix. The first WDR spotted hydrogen leaks, valve needs, weather effects, and comms glitches. The confidence test checked seals but hit flow problems. Now with a new filter, teams hope for smooth sailing.

Safety tops the list. Isaacman stressed they won't launch until ready. Astronauts will fly about 10 days, testing Orion systems on the moon loop.

Engineers review every bit of data. They tweak procedures, like using breathing air instead of nitrogen in Orion's service module for closeout safety. Ground teams keep purging lines and setting conditions.

A news conference Tuesday at 1 p.m. EST will cover early WDR-2 thoughts. NASA streams it live. Work continues non-stop at the pad. The rocket sits fueled-up ready, systems chilled and watched.

Past Artemis flights faced slips. Artemis I, the uncrewed test, launched in 2022 after years of delays. Now with humans, every step draws close eyes. Success here clears the path for Artemis III, the first moon landing since 1972.

Teams stay focused. They push through weather, leaks, and gear hiccups. Each test teaches more about the 322-foot rocket. Hydrogen management proves the biggest hurdle so far. Flow rates, seals, and airborne limits demand precision.

Orion closeouts mimic crew entry. Technicians in white suits practice hatches and seats. This builds muscle memory for the real day.

As February 19 nears, eyes turn to Launch Control. Will the second WDR hit all marks? Controllers aim deeper into countdown than before. A clean run could lock in March.