Artemis, NASA's Moon landing program

What is NASA’s Artemis program?

Through the Artemis program, NASA aims to send astronauts to the lunar south pole and eventually establish a permanent presence on the Moon. Artemis I (2022) was an uncrewed test of the Space Launch System and Orion capsule on a lunar flyby; Artemis II will be the first crewed lunar flyby; Artemis III aims to send a crew to low-Earth orbit to dock with a future lunar lander; and Artemis IV aims to land a four-person crew on the Moon's south pole. Subsequent missions in the program will aim to establish a sustained lunar presence via an orbital station and surface infrastructure.

NASA’s Artemis program is designed to land humans on the Moon quickly and focus on Mars as a long-term human spaceflight goal after that. The preliminary short-term plan involves using both commercial rockets and NASA's Space Launch System, the Orion crew capsule, and a commercial lunar landing system. A small space station in lunar orbit, called the Gateway, would serve future surface missions.

The history of crewed lunar exploration

Humans have not left Earth orbit since Apollo 17 returned from the Moon in 1972. NASA has been trying to change that since 2004, when then-U.S. President George W. Bush announced the Vision for Space Exploration, an initiative to send humans back to the Moon and eventually to land on Mars. Since then, NASA's deep space efforts have had a number of names: Constellation (2004-2010, targeting the Moon and Mars), Journey to Mars (2015-2018, targeting cislunar space, an asteroid, and Mars), and Moon to Mars (2018 to present, targeting the lunar surface and Mars).

The Artemis program is a result of the Trump administration's Space Policy Directive 1 and a March 26, 2019, speech by former Vice President Mike Pence directing NASA to reach the Moon by 2024. That date has now slipped to 2028.

The Moon in Widescreen Apollo 12 astronauts took this picture of the Moon during their coast back to Earth in 1969.Image: NASA/Edited by The Planetary Society

The Artemis missions

Artemis I

Artemis I was an uncrewed flight test of the Space Launch System (SLS) and Orion. On Nov. 16, 2022, it successfully lifted off from NASA’s Kennedy Space Center in Florida. The SLS launched Orion toward a lunar orbit, with the crew capsule ultimately flying around the Moon and then returning to Earth. The Artemis I mission was a critical test and helped demonstrate what it would take for both vehicles to be ready to carry astronauts. It exposed a potential issue with Orion’s heat shield, which NASA later adjusted Artemis II to account for.

Artemis II

Artemis II will be the first crewed mission of the Artemis program, sending humans beyond low-Earth orbit for the first time in over 50 years. A four-person crew — NASA’s Reid Wiseman, Victor Glover, and Kristina Koch, as well as the Canadian Space Agency’s Jeremy Hansen — will fly Orion into orbit around the Moon. The Artemis II crew will test out the spacecraft, then return to Earth without touching down on the lunar surface.

Artemis III

Artemis III was originally going to be the first Artemis mission to touch down on the Moon. But in early 2026, NASA announced the landing would instead happen during Artemis IV, effectively breaking up the lunar program into more missions to reduce risk as the agency tests out new procedures and technology along the way. Now, Artemis III will involve a crewed launch into low Earth orbit, where Orion will dock with a future lunar lander built by either SpaceX or Blue Origin. This will test out a crucial step in the landing plan for Artemis IV.

Artemis IV

Artemis IV will be the real showstopper of the new lunar program. Tentatively slated for 2028 (though its launch date depends on several factors), Artemis IV will attempt to land in SpaceX’s Starship near the south pole of the Moon. The current mission plans are a bit complicated: the astronauts will launch on the SLS and Orion, while Starship launches to meet them around the Moon. Two astronauts will stay in orbit around the Moon in Orion, while two enter Starship and make their way down to the lunar surface.

Artemis V and on

After Artemis IV, additional missions may set up and add on to the lunar Gateway station, deliver rovers and habitation modules to the Moon’s surface, and begin attempts to harvest resources like water and oxygen there.

Artemis I Orion lunar flyby NASA's Artemis I Orion spacecraft flies past the Moon in this image captured by a camera at the tip of one of the spacecraft's solar arrays on Nov. 21, 2022. Orion launched atop the Space Launch System on Nov. 16 and used the lunar flyby to enter a Distant Retrograde Orbit (DRO) around the Moon. The dark, ringed area on the Moon's surface is the Mare Orientale impact basin.Image: NASA

How does the Artemis program work?

Artemis depends on several different spacecraft, all working together.

The Space Launch System

The Space Launch System (SLS) is a massive rocket based on Space Shuttle-derived technology. It is essentially a larger version of the Shuttle stack that trades out the winged orbiter for either cargo or the Orion crew capsule on top.

The vehicle's core stage is a stretched Shuttle external fuel tank powered by four Space Shuttle (RS-25) main engines. (During the Shuttle program these engines were refurbished and reused; for SLS they will be ditched in the ocean.) Assisting the core stage during the initial phase of flight is a modified pair of five-segment Space Shuttle solid rocket boosters.

Orion

Orion is a crew vehicle capable of supporting up to four astronauts on deep-space journeys, similar in concept but having a larger interior than the gumdrop-shaped Apollo capsules. Unlike capsules designed solely for transportation to low-Earth orbit, Orion’s heat shield can withstand the high-velocity reentry necessary when returning from deep space. The Orion spacecraft consists of three major components: a pressurized crew capsule, a service module, and a launch abort tower, which is nominally jettisoned during ascent.

Gateway

The Gateway is a small space station in lunar orbit that would function as a fuel and supply depot, a science outpost, and a waypoint for missions to and from the lunar surface. NASA has asked commercial companies to provide Gateway cargo transportation services, similar to the way it does for the International Space Station.

Lunar landers

NASA asked commercial companies to build lunar lander systems that would eventually dock with the Gateway. In April 2021, the space agency announced it had selected SpaceX's Starship to help land humans on the Moon. NASA selected a second landing system, Blue Origin's Blue Moon lander, in May 2023.

A visiting Orion crew would board the lander, take it to the surface, and return in either an ascent module or the entire vehicle. Early landers would only be capable of short surface stays, while future vehicles would be able to house crews through the lunar night (a roughly two-week period).