[6] Another proposal suggested in 2017 was to take four astronauts aboard Orion on an 8-to-21–day trip around the Moon to deliver the first element of the Deep Space Gateway.

On 20 March, the engine section was mated with the Artemis II core stage in Building 103 at the Michoud Assembly Facility in New Orleans.

[18][19] Finally in June 2024, NASA announced the planned delivery of the fully outfitted core stage to KSC in July 2024, which was successfully carried out from the 16th to the 25th.

[20][21][22] The adapters needed for integration of the full vehicle also reached substantial completion in June 2024, and arrived at Kennedy Space Center in September 2024.

[28] In December 2024, outgoing Administrator Nelson announced that the launch was delayed due to the months of engineering investigations into issues with the life support system and heat shield,[33][34] but should occur no later than April 2026.

Artemis II is to be crewed by four astronauts: Commander Reid Wiseman, Pilot Victor Glover along with Mission Specialists Christina Koch and Jeremy Hansen.

[40] The Artemis II mission plan is to send four astronauts in the first crewed Orion spacecraft into a lunar flyby using the Block 1 variant of the Space Launch System.

During this time the crew will perform various checkouts of the spacecraft's life support systems as well as an in-space rendezvous and proximity operations demonstration using the spent Interim Cryogenic Propulsion Stage (ICPS) as a target.

When Orion reaches perigee once again, it will fire its main engine to complete the TLI maneuver, which will send it to a lunar free-return trajectory, before returning to Earth.

[42] The O2O hardware will be integrated into the Orion spacecraft and includes an optical module (a 4-inch [100 mm] telescope and two gimbals), modem and control electronics.