Artemis IV

The launch will be on a Space Launch System rocket from the usual Launchpad 39B at NASA’s Kennedy Space Center in Florida, USA. The mega Moon rocket 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. The advanced exploration upper stage booster increases the SLS’s rocket’s capability from 27 to 42 tonnes, allowing for more hardware to be sent to the Moon with the Orion spacecraft.

The extra boost is necessary to bring ESA’s International Habitation Module (I-Hab) to the lunar Gateway, which will serve as the primary habitat module of the lunar station.

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.

Second Artemis Moon landing

Part of the Artemis IV mission will see two astronauts leave Gateway and descend to the Moon for a stay on the lunar surface – the second Moon landing for Artemis.

While two astronauts stay on the Gateway and continue setting up I-Hab, two Artemis colleagues will transfer to a human landing system that will undock from the Gateway and land on the Moon. During a complete orbit of Orion and Gateway, the two moonwalkers will conduct science on the Moon and return to Gateway six days later.

Return home

Once reunited, the astronauts will have up to five days in orbit to transfer supplies and samples from the human landing system to Orion for the return home.

When ready and the hatches are closed, the European Service Module will gently pull Orion away from the Gateway and start its voyage back to Earth. Much like in the Artemis III mission, Orion will get a gravity assist from the Moon, with the European Service Module’s main engine firing to boost itself around the Moon and onwards to Earth.

Approaching Earth from the south reentry into Earth’s atmosphere will see Orion arrive at speeds of about 40 000 km/h. Less than an hour before touchdown the European Service Module will say farewell to the Orion Crew Capsule and together with the Crew Module Adapter the expendable parts of Orion will burn up harmlessly over uninhabited parts of Earth.

Our atmosphere and 11 parachutes will reduce the spacecraft’s speed for a splashdown in the Pacific Ocean.

Technical details

Launch: 2027

Duration: 3-4 weeks

Launch Mass

• Launch mass of European Service Module: 13 500 kg
  • 8600 kg of propellant
  • 240 kg of drinking water
  • 30 kg of nitrogen
  • 90 kg of oxygen
• Total Orion launch mass: over 20 tonnes
  • Orion payload volume up to 0.57 m3
  • Orion payload mass up to 380 kg
• I-Hab module
  • Pressurised volume: 36 m3
  • Habitable volume: 10 m3
  • Maximum launch mass: 10 000 kg

Artemis IV step by step:

1. Launch by Space Launch System from pad 39B at NASA’s Kennedy Space Center, USA
2. Mission control perform final checks in low-Earth orbit
3. Translunar injection by exploration upper stage (EUS)
4. Transposition manoeuvre : Orion separates from EUS, turns around, docks with I-Hab and extracts it from EUS
5. Orion and European Service Module take I-Hab to the Moon
6. Flyby of the Moon with gravity assist
7. Arrival at Near Rectilinear Halo Orbit
8. Docking with Gateway and connection of I-Hab to Gateway
9. Transfer of equipment and astronauts
10. Install and activate I-Hab as part of Gateway
11. Prepare lunar lander for departure to Moon
12. Undocking of human landing system with two astronauts for lunar sortie
13. Orion does six-day complete orbit of Moon while docked to the Gateway as two astronauts work and explore the lunar South Pole.
14. Liftoff of human landing system from the Moon
15. Human landing system docks with Gateway
16. Transfer of supplies and setup for home trip to Earth
17. Orion undocks from Gateway with all four astronauts
18. Departure from Near Rectilinear Halo Orbit
19. Main engine fires for lunar gravity assist back to Earth
20. Homeward cruise
21. Separation of the Crew Module from the expendable elements of Orion (the European Service Module and the Crew Module Adapter)
22. Reentry of the Crew Module and splashdown in the Pacific Ocean