Artemis II will be the first test flight of NASA’s Space Launch System and Orion crew capsule with astronauts on board.Steve Nesius/Reuters
Last September, when NASA announced it would try to fly the Artemis II mission as early as February, 2026, it was clear that preparations would have to proceed without a hitch in order for the U.S. space agency to make that target.
Now February has arrived and so has a hitch, in the form of a hydrogen leak during a Monday dress rehearsal at the Kennedy Space Center in Florida.
The leak arose while ground crew were fuelling the Space Launch System (SLS) rocket, which is slated to send a four-person crew, including Canadian astronaut Colonel Jeremy Hansen, on a 10-day trip around the moon. Once the problem was detected, engineers worked to troubleshoot it, delaying the rehearsal. Fuelling was eventually completed, allowing the rocket to enter a simulated countdown.
But that was temporarily stopped late Monday because of a valve issue in the pressurized crew cabin. The countdown clock was stopped automatically and for good around the five-minute mark when the earlier hydrogen leak began increasing.
Canadian Jeremy Hansen is one of four astronauts slated to fly around the moon.John Raoux/The Associated Press
On Tuesday morning, mission managers announced they would no longer aim to send Artemis II on its way during the coming Feb. 8 to 11 launch opportunity, in order to allow for a thorough review of data from Monday’s exercise and to conduct a second dress rehearsal.
“The big take-away was we got a chance for the rocket to talk to us, and it did just that,” the mission’s management team chair, John Honeycutt, said during a Tuesday news briefing.
The decision means that the earliest possible date for Artemis II to lift off shifts to March 6, the start of the next five-day launch window. Suitable time frames for the mission are based on the relative positions of the Earth, moon and sun and recur approximately every four weeks.
Artemis II represents the first attempt to send astronauts looping around the moon and back in more than 53 years. In addition to Col. Hansen, who was selected to represent Canada as a mission specialist, the crew consists of commander Reid Wiseman, pilot Victor Glover and mission specialist Christina Koch.
Once the decision was made to postpone, the Houston-based crew were released from a prelaunch quarantine. They will continue training in Texas instead of coming to Florida this week as planned.
Artemis II is only the second full test flight of the SLS rocket and Orion crew capsule.
The first test, Artemis I, was similarly plagued by a hydrogen leak, which ultimately delayed its flight for months. After lifting off in November, 2022, the crewless spacecraft successfully completed its 25-day mission.
NASA readies for historic Artemis II flight around the moon
At Tuesday’s briefing, launch director Charlie Blackwell-Thompson said the flight team had been able to apply many lessons about managing a hydrogen leak. However, she added there is still work to be done.
When Artemis II was rolled out to its launch pad in January, officials made clear that the date of its liftoff hinged on the results of the “wet” dress rehearsal. This requires fully fuelling the rocket with the liquid oxygen and hydrogen propellant needed for a lunar flight.
The hydrogen leak was detected at a point called an umbilical plate, where a fuel line connects to the bottom of the SLS core stage.
Despite the setback, NASA’s Moon to Mars program manager Lori Glaze said that excitement is building for the historic launch.
“You can feel it in the air when we’re out here, when we’re near the rocket. It really is spectacular,” she said.
The mission is a crucial step in NASA’s plans to return to the lunar surface with Artemis III and subsequent missions, and to establish a continuing presence on the moon.
In a statement, Frédérick Fink, a spokesperson for the Canadian Space Agency, said the organization was confident “NASA’s decision to delay the launch of the Artemis II mission to March is guided by their commitment to the safety of the crew and the overall success of the Artemis campaign.”