ARTEMIS II’s astronauts are preparing to face the most dangerous stage of their entire mission yet – the bumpy and rough splash down back to Earth.
And to make matters all the more nail-biting, the space capsule’s heat shield to protect them from burning up through the atmosphere has a flaw.
Friday marks the end of the four astronauts’ historic 10 day lunar flyby, in which a number of major records were shattered.
Nasa‘s Reid Wiseman, Christina Koch and Victor Glover, alongside Canadian Space Agency astronaut Jeremy Hansen, are set to splashdown off the coast of San Diego at approximately 5.07pm local time on Friday evening (1.07am on Saturday UK time).
The mission has largely gone without a hitch, except for problems with the space toilet that’s been off limits for anyone needing a wee.
But there is one essential element that is being watched closely – the heat shield, a special coating applied on the bottom of the Orion capsule to protect astronauts from the 2800C temperatures on re-entry.
Read more about Artemis II
SKY-PHONE
Artemis astronauts call pals on ISS in record 230,000-mile long distance CALL
U-TURN
Journey and schedule of Artemis 2 as astronauts returning to Earth
During a test flight on the first uncrewed Artemis mission in 2022 the heat shield cracked and chunks came off.
The spacecraft was still able to return to Earth intact and a subsequent investigation found that people would have been safe had it been a crewed launch, so Nasa bosses decided it could still be used for the Artemis II mission.
Instead, experts have made some alterations to the flight path this time around.
Orion took a special skip manoeuvre on re-entry for Artemis I where the capsule briefly lifted back up to slow the descent down a little.
This won’t be repeated on Artemis II, instead it’ll just go straight down at almost 24,000 mph and engulfed in a fireball outside.
During this tense period communications will also briefly blackout.
Sign up for The Sun Tech newsletter for gadgets, games & more
Hello! I’m Sean Keach, The Sun’s Head of Technology and Science
I’ve been writing about gadgets, games and the future of technology for more than a decade.
During that time I’ve penned thousands of articles, filmed hundreds of videos, talked tech on TV and radio, and travelled around the world to bring you the latest on Apple, Meta, Google, Amazon, Netflix and more.
And I’ve got a weekly newsletter called The Sun Tech that you can read for free every Thursday.
I bring you the latest from the world of tech, including behind-the-scenes action, exclusive content, expert analysis, and plenty of help advice – so please follow along!
It’ll be a steeper ride for the astronauts, but it’ll also shorten the re-entry period and thereby reducie the amount of time it’s exposed to extreme heat.
Speaking on Tuesday, Nasa Administrator Jared Isaacman said: “In terms of what keeps me up at night, my blood pressure will be elevated until they’re under parachutes in the water off the West Coast.
“There’s no plan B there. That is the thermal protection system. The heat shield has to work.”
Astronaut Wiseman is confident all will be fine as the root cause was identified in the investigation after Artemis I.
“If we stick to the new reentry path that Nasa has planned, then this heat shield will be safe to fly,” he said last July.
But not everyone is convinced it is a safe bet.
Former Nasa engineer and astronaut Charlie Camarda, who is also an expert on heat shields, warned: “The technical and organisational issues associated with the Orion heat shield represent a serious risk.
“History shows accidents occur when organisations convince themselves they understand problems they do not. This issue exhibits the same patterns that preceded past catastrophes.”
Nasa is already preparing its next Artemis mission for 2027 which will be another crewed test.
After that it’s the most talked about Artemis IV mission in 2028, where astronauts will walk on the Moon.