Animation showing the Orion spacecraft, powered by the European Service Module-4, as it separates from the SLS second stage and returns to collect the Gateway module I-Hab, at the beginning of the Artemis IV mission.

The mega Moon rocket SLS will propel four astronauts inside Orion to the Moon but Artemis IV will be the first mission to use a new second stage, replacing the interim cryogenic propulsion stage used on the first three Artemis missions.

Once the exploration upper stage has finished its boost to the Moon, Orion will detach from the second stage and the European Service Module will use its 24 reaction control thruster engines to turn itself around and return to the I-Hab that flew to space under a separate compartment of the SLS rocket fairing. Orion will then attach itself to I-Hab, pull it away from the second stage and tug it to the Gateway on its four-day journey to the lunar Gateway’s orbit.

Orion and the European Service Module will tug the module into position around the Moon and dock with the Gateway, pushing I-Hab into position. I-Hab will feature four docking ports, two radial ports for a cargo and a lunar lander vehicle and two axial ports for connection to other lunar gateway elements.

More on the Artemis IV mission.