When is Nasa's Moon mission launch and what will Artemis do?
NASANasa is aiming for an early April launch for the first crewed mission around the Moon in more than 50 years.
The Artemis II mission, which will last about 10 days, will take its astronauts further into space than anyone has been before.
It aims to set the stage for an eventual human landing on the lunar surface for the first time since the Apollo missions of the 1960s and 70s.
When will Artemis II launch?
Nasa's next possible dates are 1, 2, 3, 4, 5, 6 and 30 April 2026.
In December 2024, the space agency set a deadline to launch Artemis II before the end of that month.
A potential February launch was ruled out after a pre‑flight test - known as a wet dress rehearsal - was cut short when hydrogen rocket fuel leaked from a connection linking the launch tower to the rocket.
A March launch was also ruled out after a helium leak was discovered.
Beyond resolving the technical issues, mission planners also have to wait until the Moon is in the right part of its orbit, so launch windows are timed accordingly.
In practice, this creates a pattern of roughly one week at the start of each month when the rocket can be pointed in the right direction, followed by about three weeks with no launch opportunities.
What will the Artemis crew do during the Moon mission?
Artemis II's crew of four is made up of Nasa commander Reid Wiseman, pilot Victor Glover and mission specialist Christina Koch. A second mission specialist, Jeremy Hansen from the Canadian Space Agency, will also be on board.
The mission involves the first crewed flight of Nasa's gigantic Space Launch System (SLS) rocket and the Orion space capsule.
Once they are safely in orbit, the astronauts will test how the Orion handles. This will involve manually flying the capsule in Earth orbit to practise steering and lining up the spacecraft for future Moon landings.
They will then head out to a point thousands of kilometres beyond the Moon to check Orion's life‑support, propulsion, power and navigation systems.
The crew will also act as medical test subjects, sending back data and imagery from deep space.
They will work in a small cabin in weightlessness. Radiation levels will be higher than on the ISS, which is in low‑Earth orbit, but still safe.
On return to Earth, the astronauts will experience a bumpy return through the atmosphere and a splashdown off the west coast of the US, in the Pacific.
Will Artemis II land on the Moon?
No. This mission is to lay the ground for a lunar landing by astronauts in the Artemis IV mission, planned for 2028.
Ahead of that, Nasa plans another crewed test mission, Artemis III, in 2027, to rehearse Orion's rendezvous and docking with one or more lunar landers and to try out the new spacesuits if they are ready in time.
Nasa has picked two rival commercial landers for Artemis: SpaceX's Starship and a craft designed by Jeff Bezos's company Blue Origin, and will decide closer to the time which vehicles fly which missions.
When Artemis IV finally flies, the astronauts will be heading to the Moon's south pole.
After this, the aim is to have another landing later in 2028 with the Artemis V mission, to build up the capability for a sustained human presence on the Moon.
Nasa has paused work on its planned Gateway station in lunar orbit. Further Artemis missions will focus on building up a Moon base and flying crews regularly to the surface, with more landings, new surface modules and robotic rovers to follow.
More countries will join the effort, with astronauts from a widening group of nations living and working on and around the Moon for longer stays.
When was the last Moon mission?
The last crewed Moon mission was Apollo 17, which landed in December 1972 and returned to Earth later that month.
In all, 24 astronauts have travelled to the Moon and 12 of them have walked on its surface, all during the Apollo programme. Of the 24 to have been to the Moon, just five are still alive.
America first went in the 1960s, primarily to beat the Soviet Union to assert its geopolitical and technological dominance. Once that goal was achieved, political enthusiasm and public interest ebbed, as did the money for future Moonshots.
The Artemis programme grew out of a desire to return humans to the Moon, but this time for a longer-term presence built around new technology and commercial partnerships.
Do other countries plan to send astronauts to the Moon?
Several other countries have ambitions to put people on the Moon in the 2030s.
European astronauts are set to join later Artemis missions and Japan has also secured seats.
China is building its own craft, targeting a first landing near the Moon's south pole by 2030.
Russia continues to talk about flying cosmonauts to the surface and building a small base sometime between about 2030 and 2035. However, sanctions, funding pressures and technical setbacks mean its timetable is highly optimistic.
India has also expressed ambitions to one day see its own astronauts walking on the Moon.
Following the success of Chandrayaan 3's landing near the lunar south pole in August 2023, India's space agency set out a goal of sending astronauts to the Moon by about 2040. This would be part of a push to move its human spaceflight programme beyond low Earth orbit.
Additional reporting by Kevin Church and Emily Selvadurai.