NASA confirmed the delay on March 16, moving the rollout of the Artemis II rocket from the Vehicle Assembly Building to Launch Pad 39B from March 19 to no earlier than March 20. The agency remains optimistic that the long-delayed return of humans to lunar space will still happen in early April.
Teams identified an electrical harness for the flight termination system on the core stage needed replacement. The flight termination system is responsible for bringing a malfunctioning rocket's flight to an abrupt end, and problems with it would be catastrophic. Discovering and fixing such an issue inside the assembly building, rather than at the launch pad, represents good engineering practice.
Despite the delay, NASA remains hopeful that everything will be ready for an April 1 launch attempt. Teams are keeping an eye on the weather as the big day approaches.
The delay marks the latest setback for a programme that has faced repeated postponements. The Artemis II rocket was forced to return to the VAB following an issue with the flow of helium to the upper stage after a February 21 wet dress rehearsal. As well as resolving the problem, which was caused by a seal becoming dislodged, engineers also fitted a new set of flight termination batteries and performed other tasks, including replacing a seal on the core stage liquid oxygen line feed system.
The 12-hour journey from the assembly building to the launch pad represents the culmination of months of preparation. The mission will carry NASA astronauts Reid Wiseman, Victor Glover, and Christina Koch, along with Canadian Space Agency astronaut Jeremy Hansen, on a free-return trajectory around the Moon and back to Earth. It is the first crewed deep space mission since Apollo 17 in 1972, and the first since then to reach the Moon's vicinity.
No further wet dress rehearsals are planned for the rocket upon its return to the launch pad. NASA managers hope that the next time it is loaded with propellant will be the time the SLS is finally launched.
Beyond Artemis II, NASA Administrator Jared Isaacman announced that the follow-on mission, Artemis III, will be a crewed mission close to Earth flying in mid-2027 that will have Orion dock with one or both of the human landing system spacecraft being developed by SpaceX and Blue Origin, setting up two potential moon landing missions in 2028. The restructured timeline reflects a push to accelerate the programme's pace and reduce the years-long gaps between missions.