NASA began preparations for the final countdown to Artemis II, a crewed flight around the Moon scheduled to launch on April 1. The two-hour launch window for the Space Launch System rocket was due to open at 22:24 UTC, with the mission team reporting to stations 49 hours and 50 minutes before liftoff.
The formal count was set to start 10 minutes later, at L-49 hours and 40 minutes. Propellant loading was planned for about L-9 hours and 55 minutes. Four hours before launch, the crew would be secured inside the Orion capsule. If the sequence proceeded normally, the vehicle's RS-25 engines would ignite at T-6.36 seconds, followed by the solid rocket boosters.
The crew consists of Canadian Space Agency astronaut Jeremy Hansen and NASA astronauts Christina Koch, Victor Glover and Reid Wiseman. Their trajectory around the Moon could take them farther from Earth than the Apollo 13 crew, which holds the human distance record. Artemis II will not enter lunar orbit in the manner of Apollo 8, but it is designed to carry people farther from Earth than any crewed vehicle has travelled in more than half a century.
NASA expected Orion to pass the Moon on April 6 if launch occurred on April 1. Splashdown in the Pacific Ocean was scheduled for approximately 0006 UTC on April 11. During the passage behind the Moon, communication with Earth was expected to stop for 30 to 50 minutes, depending on the precise launch time. The astronauts planned to record photographs, video and observations during that interval for later transmission.
The countdown followed technical delays. Leaks found during a wet dress rehearsal and a helium-flow problem required the vehicle to return to the Vehicle Assembly Building. At the start of the countdown, weather was the only identified constraint to an April 1 attempt, with an 80% probability of acceptable conditions. That estimate would decline to 75% for a delay of 48 hours.
Artemis II was initially positioned as preparation for the Artemis III lunar landing. NASA subsequently changed Artemis III into a 2027 low-Earth-orbit test of landing technologies, with Artemis IV planned as the first landing mission in 2028. Longer-term architecture remained less certain amid a proposed Moon base, a possible pause for the Gateway station and reports that commercial launch systems could replace SLS after Artemis V.
The immediate objective remained narrower: complete the countdown, launch Orion safely and validate a crewed deep-space mission before later landing attempts.
Any technical issue or worsening weather during the count could still have postponed the scheduled April 1 departure.
