If successful, Artemis I would pave the way to a first crewed SLS-Orion mission, an out-and-back flight around the moon designated Artemis II, as early as 2024, followed a year or more later by an Artemis III trip to the lunar surface.
Artemis III will be much more complex, integrating the SLS-Orion with spacecraft to be built and flown by entrepreneur Elon Musk's company SpaceX. Those include SpaceX's heavy-duty Starship launch and lunar-landing vehicle, still under development, and components still to be constructed including an orbital fuel depot and space tankers. Even the new moon-walking suits remain to be designed.
The plan would be for a four-person Orion crew to dock in space with a SpaceX lander to ferry two astronauts to the moon's surface for nearly a week.