Nasa has announced significant changes to its Artemis programme, adding an extra mission before attempting to land astronauts on the Moon for the first time in more than half a century.
Under the revised plan, Artemis III will no longer aim to send humans to the lunar surface.
Instead, it will launch by mid-2027 into low-Earth orbit to test critical systems and practice docking with a lunar lander.
The first crewed Moon landing is now expected to take place during Artemis IV in 2028, with the possibility of a second landing, Artemis V, in the same year.
The changes come as the US space agency confronts technical setbacks, safety concerns and mounting pressure to ensure mission success.
The restructuring was outlined by Nasa’s administrator, Jared Isaacman, who said the additional step would reduce long gaps between launches and lower risk.
He described the current architecture as “not a pathway to success.”
Under the new sequence, astronauts will test the Orion spacecraft and a lunar lander together in low-Earth orbit before committing to a landing attempt.
Nasa said the approach would allow engineers to refine technology and address challenges incrementally.
Artemis II, which will send four astronauts on a 10-day journey around the far side of the Moon without landing, has also been delayed.
Originally targeted for early March, the launch is now scheduled for no earlier than April after a helium issue was discovered in the rocket’s upper stage.
The Space Launch System rocket has been moved from the launchpad back to the Vehicle Assembly Building at the Kennedy Space Center in Florida for repairs.
A central component of the programme, the lunar lander, has yet to be finalized.
SpaceX holds a contract to develop a lander using its Starship rocket, though delays have prompted Nasa to seek a streamlined plan.
The agency has also asked Blue Origin to propose an accelerated alternative.
The United States faces growing competition from China, which is aiming for a crewed lunar landing by 2030.
Both nations have identified the Moon’s south pole as a target for future missions and potential base sites.
Nasa maintains that the revised timeline will still support a return to the lunar surface in 2028 while reducing operational risks.