The launch of the mission that aims to put humans back on the moon is on course for lift-off as planned, NASA bosses say.
Artemis 1 was given the green light last week during a flight readiness review at Kennedy Space Center.
It will blast off from Florida today – drawing hundreds of thousands of spectators to the state’s space coast.
In a briefing ahead of the big day, concerns were expressed over possible lightning strikes (several bolts struck a launchpad on Saturday, leading to concern over potential damage to its critical systems). And a NASA spokeswoman told space fans that the lift would be pumping out “more of a fireball” than recent launches.
But as the launch has the all-clear, here’s what you need to know about the historic space endeavour.
What does Artemis hope to achieve?
The mission is made up of three stages.
The first is a 42-day uncrewed flight around the moon. It will test the huge rocket and the Orion spacecraft that astronauts will eventually travel in.
While in space it will deploy 10 CubeSats (a type of miniaturised satellite), which will perform a variety of work in deep space, from studying how radiation affects yeast DNA to hunting for water ice on the moon.
Weather is a big focus of the test mission, with galactic cosmic rays presenting the biggest risk to future crews.
Newly built space weather centres will research solar wind (charged particles released from the Sun), solar fluxes (concentrated sunlight), and coronal mass ejections (large expulsions of plasma and magnetic field from the top layer of the Sun).
A new lunar vehicle will also combine the best from the Apollo moon buggies and Mars rovers, allowing astronauts to pilot them in person and remotely.
Orion will fly 60 miles above the moon at its closest, and during re-entry weeks later will emerge into the Earth’s atmosphere at 25,000mph before splashing down off the California coast on 10 October.
Cameras inside and outside of Orion will share images and video throughout the mission.
If all goes to plan, it will have been in space longer than any human craft in history without docking to a station.
A crew will strap in and blast off for the first time for more testing during Artemis 2. The four astronauts have so far not been named, but this stage is pencilled in for 2024.
Lasting about eight to 10 days, they will do a lunar flyby before returning to Earth.
Humans will finally land on the moon again during Artemis 3, with NASA saying the crew will include the first woman and person of colour.
The timeline depends on how well the previous missions go, but it’s currently slated for 2025.
NASA hopes to build a base camp and conduct annual missions and use it as a test bed for even more ambitious missions, starting with getting a human to Mars.
Most fun fact about the mission?
The Orion capsule will have just mannequins and a soft toy on board.
The mannequin captain is called Commander Moonikin Campos, who will sit in the commander’s seat throughout (see more below).
A Snoopy soft toy will also float around the Orion capsule as a zero gravity indicator.
How powerful is the Artemis 1 rocket?
The 98-metre Space Launch System (SLS) is the most powerful rocket NASA has ever built and in this crucial testing phase it will fly further than any spacecraft built for humans: 40,000 miles past the far side of the moon and 280,000 miles from Earth.
The megarocket’s 8.8 million pounds of thrust at launch is 13% more than the Space Shuttle, and 15% greater than the Saturn V rocket used on the Apollo missions.
Each of the two boosters generates more thrust than 14 four-engine commercial airliners, according to NASA, and will fire for 126 seconds, providing more than 75% of the vehicle’s thrust before they break off.
It’s also powered by four RS-25 engines, with the outbound trip to the moon taking several days.
When’s launch day, and how can I watch?
The first Artemis mission is set to blast off from Kennedy Space Center today, with a two-hour launch window that opens at 8.33am local time (1.33pm UK).
Streaming of the launch will start on NASA’s website at 6.30am local time (11.30am UK) – but there’s also a stream available now of the rocket on the launchpad.
Hollywood stars Jack Black, Keke Palmer and Chris Evans will feature in a live broadcast of the launch.
When was the last time a human was on the moon?
More than 50 years ago: it was Apollo 17 in December 1972 – about three and a half years after Neil Armstrong made history with the first moon walk.
With President Kennedy’s big goal achieved, the final three Apollo missions were cancelled and NASA’s funding cut.
The new missions are named after Greek goddess Artemis, the twin sister of Apollo. She was the goddess of the hunt, the moon, and chastity.