Artemis crew break away from Earth's orbit to the Moon

The four Artemis astronauts have fired up their spacecraft's engine to break away from Earth's orbit towards the Moon, a milestone that commits NASA to the first crewed lunar flyby in more than half a century.

With enough thrust to accelerate a stationary car to motorway driving speed in less than three seconds, the Orion capsule engine blasted the astronauts on their trajectory towards the Moon, which they now will loop as part of the ten-day Artemis II mission.

The burn lasting just under six minutes propelled the astronauts on their three-day voyage towards Earth's natural satellite, the first since 1972.

"Looks like a good burn, we're confirming," mission control in Houston said.

"The crew is feeling pretty good up here on our way to the Moon," said astronaut Jeremy Hansen.

"Humanity has once again shown what we are capable of," he added.

The burn came one day after the orange-and-white Space Launch System (SLS) rocket carrying the Orion capsule blasted off from Kennedy Space Center in Florida for the long-anticipated journey around the Moon .

Now that they are moon bound, there is no turning back: the astronauts are on a "free-return" trajectory, which uses the Moon's gravity to slingshot around it before heading back towards Earth without propulsion.

In the event that something goes wrong, the astronauts are wearing suits that also serve as "survival systems" - in the unlikely case of a cabin depressurisation or leak, they will maintain oxygen, temperature controls and the correct pressure for up to six days.

The astronauts - Americans Reid Wiseman, Victor Glover and Christina Koch and Canadian Hansen - spent their first hours in space performing checks and troubleshooting minor problems on the spacecraft that has never carried humans before, including a communications issue and a malfunctioning toilet.

Watch: NASA rocket launches from Florida for Artemis II mission
They began the second day of their mission by playing Green Light by John Legend and Andre 3000, NASA said - a reference to the go signal they would soon get to fire up the engine and get moving towards the Moon.

They also had their first workouts of the mission on the spacecraft's "flywheel exercise device" - each astronaut will carve out 30 minutes a day for fitness, a bid to minimise the muscle and bone loss that happens without gravity.

The ten-day Artemis II mission is aimed at paving the way for a Moon landing in 2028.

The mission marks a series of historic accomplishments: sending the first person of colour, the first woman and the first non-American on a lunar mission.

If all proceeds smoothly, the astronauts will set a record by venturing farther from Earth than any human before - more than 402,000km.

It is also the inaugural crewed flight of SLS, NASA's new lunar rocket.

SLS is designed to allow the United States to repeatedly return to the Moon with the goal of establishing a permanent base that will offer a platform for further exploration.

It was meant to take off as early as February after years of delays and massive cost overruns.

But repeated setbacks stalled it and even necessitated rolling the rocket back to its hangar for repairs.

The current era of American lunar investment has frequently been portrayed as an effort to compete with China, which aims to land humans on the Moon by 2030.

During a post-launch briefing, NASA chief Jared Isaacman said competition was "a great way to mobilise the resources of a nation".

"Competition can be a good thing," he said, adding "we certainly have competition now".

The Artemis programme has come under pressure from US President Donald Trump, who has pushed its pace with the hope that boots will hit the lunar surface before his second term ends in early 2029.

But the projected date of 2028 for a landing has raised eyebrows among some experts, in part because Washington is relying heavily on the private sector's technological headway.