Artemis II Delayed to March
NASA’s Artemis II mission will launch no earlier than March due to several issues that were encountered during a launch rehearsal last night. Hydrogen leaks, similar to those seen during the Artemis I campaign in 2022, were the primary culprit; teams will use the next few weeks to resolve these issues and conduct a second rehearsal. As February’s launch period only runs through the 11th, the earliest Artemis II can fly will be the next launch period, which opens March 6th.
The Wet Dress Rehearsal (WDR) held on February 2nd had previously been pushed from Saturday, January 31st due to unusually cold weather at the launch pad in Florida. Low temperatures into Monday also delayed the start of the test. The WDR was planned to closely resemble a real launch campaign, involving fueling (or “tanking”) the Space Launch System rocket, preparing the Orion spacecraft for flight as if astronauts were onboard, and rehearsing the terminal countdown until just before engine ignition. The team would also practice a few options to reset the countdown in the event of minor issues.
In reality, the WDR ran into a few challenges. Chief among them were hydrogen leaks; the umbilical connection used to feed liquid hydrogen from the launch pad into the core stage saw high leak rates several times throughout the tanking process. Teams deployed a strategy they learned from Artemis I, which involved pausing the hydrogen flow and warming up the interface to allow the connection to re-seal itself. This was done successfully several times until the core stage was fully fuelled. Achieving this milestone on the first attempt marks a major improvement from the protracted Artemis I WDR campaign.
Other technical problems during the rehearsal included communications dropouts and a few hiccups during Orion closeout procedures, including hatch closure and pressurization. Despite these challenges, the team was able to press onwards, targeting a simulated T-0 just after midnight. Ultimately, the test was aborted due to a second spike in the hydrogen leak rate at T-5:15, shortly after the core stage began pressurizing for flight. This triggered an automatic halt by the ground launch sequencer, ending the test earlier than planned.
During a press event held on February 3rd, NASA Associate Administrator Amit Kshatriya shared that the team was still in good spirits to press on with additional testing. ESDMD Acting Administrator Lori Glaze said that NASA currently expects that this work can be completed on the pad, without rolling SLS and Orion back into the Vehicle Assembly Building. Changes from Artemis I have increased the length of time that the full stack can remain on the pad. Mr. Kshatriya stressed that the team is not overly concerned about schedule pressure, and Dr. Glaze highlighted that the mission has launch windows each month continuing past April if needed.
Launch Director Charlie Blackwell-Thompson explained that the second WDR will focus on the unmet objectives from Monday’s test: proceeding through terminal count, demonstrating a 3-minute hold capability, and practicing a recycle within the launch window to target a new T-0—all aimed at improving flexibility for a real launch attempt.
In the meantime, the crew of Artemis II has been temporarily released from quarantine, and the astronauts had breakfast with their families early this morning. They will continue training ahead of the next launch attempt, which could be as soon as March 6th pending a successful completion of the second WDR campaign. Mr. Kshatriya stressed during the press event that NASA is prioritizing the success of Artemis II above all else. He cautioned against striving for an inflexible, “operational” approach to spaceflight, noting that there will always be opportunities to learn and improve the safety of NASA’s SLS and Orion systems.
