NASA's Artemis II mission to send astronauts around the Moon and back will not launch until 1 April 2026 at the earliest.
The space agency said its March 2026 launch window was scrubbed after engineers found a problem with the flow of helium to the rocket’s upper stage, late in February.
The move follows the scrubbing of an earlier launch date of 8 February 2026, which was cancelled after issues arose during the first Artemis II wet dress rehearsal, completed on 2 February.
Even earlier launch dates of 6 and 7 February were moved after cold weather and winds at NASA's Kennedy Space Center pushed the mission's wet dress rehearsal back.
In late February, NASA announced it would roll the Artemis II rocket back into the Vehicle Assembly Building, in order to preserve an April 2026 launch date.
More on Artemis
The mission will see a crewed spacecraft return to the Moon for the first time since the Apollo era.
While no astronauts will be setting foot on the Moon this time – we have to wait for Artemis III for that –the mission marks a pivotal moment in the programme and future plans to put a permanent human settlement on the lunar surface.
It follows the launch in on 16 November 2022 of the uncrewed Artemis I test flight.
Here's what we know about Artemis II preparations and the possible dates the mission could lift off.
Find out more about the mission with our quick Artemis II facts
Artemis II preparations
NASA is entering the final stages of preparation for the Artemis II mission, which is the first crewed flight of the Space Launch System (SLS) rocket and Orion spacecraft.
Rollout of the fully stacked vehicle to Launch Pad 39B at Kennedy Space Center in Florida was completed on Saturday 17 January 2026.
This rollout from the Vehicle Assembly Building marked the start of final integration, testing and launch rehearsals for Artemis II.
The vehicle had to travel four miles during the rollout, with the total journey taking about 12 hours.
When the Space Launch System reaches the launch pad, NASA then undertakes further mission preparations including connecting electrical power, environmental control systems and cryogenic propellant lines.
All integrated systems are powered up together at the pad for the first time, too, to check the rocket and infrastructure on the ground are working as they should be.
These tests complete, the Artemis II crew – NASA astronauts Reid Wiseman, Victor Glover and Christina Koch along with Canadian Space Agency astronaut Jeremy Hansen – will conduct a final walkdown at the pad.
Artemis II rehearsal
NASA conducted a wet dress rehearsal for Artemis II on 2 February.
This included a full launch countdown practice and demonstrating the ability to load over 700,000 gallons of liquid hydrogen and liquid oxygen into the rocket.
During a wet dress rehearsal, the teams rehearse countdown procedures, propellant loading and removal and closeout crew operations without the astronauts onboard.
Issues such as a delay in fuelling due to cold weather, a liquid hydrogen leak and a 'retorquing' of a valve associated with pressurisation of the Orion crew module capsule, meant the wet dress rehearsal took longer than planned.
NASA said engineers have also been troubleshooting dropouts in audio communication that's been affecting teams on the ground.
While a second wet dress rehearsal in late February concluded the hydrogen leak had been fixed, further issues arose around the the flow of helium to the rocket’s upper stage.
All this means that April is now the likely launch window for Artemis II, but the final timing of the launch will depend on technical readiness and orbital constraints, NASA says.
Artemis II launch periods
Artemis II can't simply launch straight away, as there multiple aspects to take into account.
Here are NASA's stated periods for Artemis II launch availability through April 2026.
Launch period 31 January – 14 February
Launch opportunities: 6, 7, 8, 10, and 11 February
Launch period 28 February – 13 March
Launch opportunities: 6, 7, 8, 9, 11 March
Launch period 27 March – 10 April
Launch opportunities: 1, 3, 4, 5, 6 April
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