NASA Halts Hydrogen Loading During Artemis II Launch Rehearsal
CAPE CANAVERAL, Fla. — NASA engineers temporarily halted the flow of liquid hydrogen into the Space Launch System rocket’s core stage during the Artemis II wet dress rehearsal on February 2, 2026, after detecting what appeared to be potential leaks. Operations resumed shortly after, and the countdown test continued.
What Happened During the Rehearsal
The wet dress rehearsal is a full-scale simulation of launch day operations, during which teams fill the rocket with propellants and run through countdown procedures without actually launching. During the test, NASA was loading both liquid hydrogen and liquid oxygen into the SLS vehicle when engineers identified several potential leak concerns during the hydrogen loading phase.
Officials temporarily halted the liquid hydrogen flow into the core stage — which houses the rocket’s four RS-25 main engines — while teams investigated. NASA said fueling resumed a short time later following assessment of the situation.
Context: Artemis II Mission
Artemis II is NASA’s planned crewed mission around the Moon using the Space Launch System and Orion spacecraft. The wet dress rehearsal was a critical milestone in the pre-launch certification process, intended to verify that ground systems, software, and procedures are ready for the actual launch. A similar rehearsal for Artemis I also encountered hydrogen leak issues, which required multiple attempts to resolve before the rocket launched in 2022.
What’s Next
NASA engineers were reviewing data from the rehearsal to assess the performance of the vehicle and ground systems. Agency officials indicated a further update would be provided as data analysis was completed. The rehearsal results will inform scheduling decisions for the Artemis II launch.
