Artemis II: Humans Return to the Moon After More Than 50 Years
NASA's Artemis II mission lifted off from Kennedy Space Center, Florida, on April 1, 2026, carrying four astronauts on the first crewed journey beyond low Earth orbit since Apollo 17 in December 1972 — a gap of over 53 years.
The Space Launch System (SLS) rocket propelled the Orion spacecraft (named "Integrity") into an elliptical Earth parking orbit approximately 49 minutes after launch; a second burn achieved a high Earth orbit at roughly 43,730 miles altitude.
The four-person crew: Commander Reid Wiseman, Pilot Victor Glover, Mission Specialist Christina Koch (all NASA), and Mission Specialist Jeremy Hansen (Canadian Space Agency).
On April 2, a translunar injection burn lasting approximately 6 minutes is planned to send the spacecraft on a free-return trajectory around the Moon — the crew will swing around the Moon on April 6 before Earth's gravity pulls them home; no lunar landing is planned.
The mission duration is approximately 10 days; re-entry and splashdown are expected around April 11.
Early mission objectives already achieved: proximity operations testing, orbital refinement manoeuvres, and troubleshooting a toilet system — demonstrating routine deep-space crew operations.
Artemis II is the second flight of SLS, the first crewed mission of Orion, and lays the technical groundwork for Artemis III — the first crewed lunar landing since Apollo 17.
The Space Launch System (SLS): Architecture and Capability
The Space Launch System is NASA's super-heavy-lift expendable launch vehicle, designed specifically to send crew and cargo beyond low Earth orbit. SLS Block 1, used for Artemis II, uses a core stage with four RS-25 engines (repurposed Space Shuttle main engines) and two five-segment solid rocket boosters (SRBs) derived from Shuttle SRBs — producing a combined thrust of approximately 8.8 million pounds at liftoff, exceeding even the Saturn V (7.6 million lbs). The core stage is 65 metres tall; the full stack with Orion and launch abort system stands 98 metres. The Interim Cryogenic Propulsion Stage (ICPS) on top, derived from the Delta IV Heavy upper stage, provides the translunar injection burn.
SLS is the critical enabling technology for Artemis II and all future Artemis missions; understanding its architecture, capabilities, and cost profile is essential for contextualising the mission within the broader space policy landscape.
The Orion Spacecraft: Design and Deep-Space Life Support
Orion is NASA's multi-purpose crew vehicle (MPCV), designed for missions beyond low Earth orbit including lunar flyby, lunar orbit, and eventually lunar landing support. The spacecraft consists of two main elements: the Crew Module (CM), a cone-shaped capsule designed by Lockheed Martin for four astronauts, and the European Service Module (ESM), built by Airbus Defence and Space for ESA, which provides propulsion, power, thermal control, and consumables. The CM's heat shield — the largest ablative heat shield ever built at 5 metres diameter — is designed to withstand re-entry speeds of ~40,000 km/h on return from lunar distances, significantly faster than ISS re-entry.
Artemis II is the crewed validation of Orion's performance — every system tested with humans aboard (ECLSS, toilet, communications, manoeuvring) must work perfectly before a crew departs for a lunar landing attempt.
Free-Return Trajectory: The Apollo 13 Lesson Applied
A free-return trajectory is an orbital path that, once initiated, uses the gravitational field of the Moon to curve the spacecraft back toward Earth without any additional propulsion burns. This trajectory was designed into early Apollo missions precisely as a safety feature: if the main engine failed after the translunar injection burn, the crew would still return home in a few days. Apollo 13 (April 1970) famously validated this principle when an oxygen tank explosion disabled the service module engine — Mission Control used a combination of the free-return trajectory and a single burn from the Lunar Module descent engine to safely return the crew. Artemis II uses a similar free-return trajectory (technically a "hybrid free-return" with a single Orion engine correction burn after the lunar flyby).
The free-return trajectory for Artemis II is both a tribute to lessons from Apollo 13 and a practical safety architecture — if Orion's main engine malfunctions beyond the Moon, lunar gravity returns the crew home without a powered burn.
- Artemis II launch: April 1, 2026, 6:24 PM EDT; Kennedy Space Center, LC-39B.
- Mission duration: ~10 days; lunar flyby April 6; splashdown ~April 11.
- Orion capsule name: "Integrity."
- SLS Block 1 thrust at liftoff: ~8.8 million lbs (vs Saturn V: 7.6 million lbs).
- Orion heat shield diameter: 5 metres — largest ablative heat shield ever built.
- Re-entry speed from lunar trajectory: ~40,000 km/h.
- Free-return trajectory validated by Apollo 13 (April 1970).
- Last crewed lunar mission before Artemis II: Apollo 17, December 7–19, 1972.
- Artemis I (November 2022): Uncrewed Orion reached 432,000 km from Earth — record for human-rated spacecraft.
- Lunar Gateway: Planned small lunar orbital station; hub for future Artemis lunar landings.