NASA’s Artemis II is planned as a roughly 10-day crewed flight that will take four astronauts farther from Earth than any human spaceflight since the Apollo era. The mission’s primary purpose is to exercise and validate spacecraft systems on a crewed mission around the Moon and back, creating the operational foundation for later missions aimed at returning humans to the lunar surface.
Launch day - The mission is scheduled to lift off from NASA’s Kennedy Space Center in Florida atop the Space Launch System, the most powerful rocket the agency has flown. NASA has stated that the launch window opens on April 1, with multiple backup opportunities available on subsequent days depending on weather conditions, technical readiness and range availability. After ascent, Orion will separate from the rocket’s upper stage and enter a highly elliptical orbit around Earth.
Days 1-2: Earth orbit checkouts - For the first one to two days after launch, the crew will remain in high Earth orbit running extensive systems checkouts. These procedures are meant to verify life-support, propulsion, navigation and communications systems on Orion before committing to the translunar phase. The checks are designed to ensure the spacecraft functions nominally under crewed load and is prepared for the demands of deep-space operations.
Translunar injection - Once ground teams and the crew are satisfied with the in-orbit checkouts, Orion’s propulsion system will execute a critical engine burn known as translunar injection. That maneuver will send the spacecraft out of Earth orbit and onto a trajectory that will carry it toward the Moon.
Days 3-4: Coast to the Moon - During the several-day transit to the Moon, the crew will continue to monitor spacecraft systems as Orion moves farther from Earth than humans have travelled on recent missions. Flight controllers will monitor communications links and navigation performance while the vehicle is en route, tracking how onboard systems perform in the deep-space environment.
Moon flyby - Orion will pass behind the Moon on a so-called "free-return" trajectory, a path that naturally swings the spacecraft back toward Earth without needing additional propulsion. During this phase the spacecraft will reach its farthest distance from Earth, a key milestone in the flight profile.
Days 5-8: Return to Earth - After completing the lunar flyby, the crew will spend several days returning home. The return leg will include further tests of deep-space capabilities, including additional checks of power systems, thermal control and crew operations while operating well beyond low Earth orbit.
Re-entry and splashdown - As Orion approaches Earth, the spacecraft will separate key components and then re-enter the atmosphere at roughly 25,000 miles per hour (40,233 kph). A central objective of the mission is to test the capsule’s heat shield during this high-energy re-entry. The spacecraft is expected to splash down in the Pacific Ocean, where recovery teams will retrieve the crew and the vehicle.
The sequence of launch, orbit checkouts, translunar injection, lunar flyby on a free-return trajectory, and high-energy re-entry is intended to validate Orion and related systems in a crewed, operational context. The mission is explicitly framed as a stepping stone toward subsequent missions that aim to place astronauts on the lunar surface later in the decade.