The moment space fans have waited more than 50 years for finally arrived last night, as NASA launched its Artemis II mission to the moon.
The launch went to plan, with Reid Wiseman, Victor Glover, Christina Koch, and Jeremy Hansen blasting into space at around 18:30 local time.
However, it wasn’t all smooth sailing, as the one toilet on board the Orion capsule malfunctioned, leaving it out of action for six hours.
Now, as the crew get further into their mission, the risks will become increasingly severe.
As we recently found out when NASA dramatically evacuated the ISS due to a medical crisis, even a small health issue could become critical in space.
Experts have also raised concerns about the heat shield, which will bear the brunt of the searing heat during re–entry through Earth’s atmosphere.
‘During the final phase of the Artemis II mission, there’s no backup, no contingency, and no chance of escape,’ Dr Macaulay explained in an article for The Conversation.
‘The four astronauts on board will be depending on a few inches of resin–coated silica to shield themselves from temperatures approaching half that of the surface of the Sun.’
The moment space fans have waited more than 50 years for finally arrived last night, as NASA launched its Artemis II mission to the moon
1. Critical systems failure
Part of what makes Artemis II riskier than NASA’s standard missions is that it is testing relatively new technology.
Compared to a spacecraft like the Crew Dragon, which has been used dozens of times, the Orion spacecraft has only been used once, during Artemis I.
‘Orion’s life support and deep–space systems have never been flown with a crew before,’ explained Chris Bosquillon, co–chair of the Moon Village Association’s working group for Disruptive Technology & Lunar Governance.
This creates a risk that one of the critical systems might fail once Orion has already left the atmosphere.
If something goes wrong during the first day, while Orion is still in low–Earth orbit, the crew can simply fire the engines to make an early return to Earth.
But if part of the engines or life–support system were to fail once the trip to the Moon had begun, things would be much more complicated.
The absolute worst–case scenario would involve multiple systems failing, including the propulsion system, leaving Orion unable to alter its course.
Mr Bosquillon says: ‘During the lunar flyby, Artemis II is dependent on onboard systems; contrary to orbital space stations, there is no option for rapid crew rescue.’
To mitigate this issue, NASA will put Orion on what is known as a ‘free return trajectory’.
This means the spacecraft will naturally swing around the moon and be tossed back towards the Earth by lunar gravity, without needing to fire its engines at all.
‘This is the solution that provides a built–in safe return baseline if major propulsion fails,’ says Mr Bosquillon.
In case of emergency, Orion is stocked with more food, water, and air than is needed for the planned 10 days and contains multiple redundant systems to keep the crew alive long enough to return home.
2. Medical emergencies
Earlier this year, NASA was forced to make the first–ever evacuation of the ISS after a crew member suffered a medical emergency.
This shows just how quickly medical issues can spiral into a crisis.
Earlier this year, NASA was forced to make t he first–ever evacuation of the ISS after a crew member, Mike Fincke, suffered a medical emergency
Living outside Earth’s gravitational pull can have devastating effects on the body, causing prolonged periods of nausea, muscle and bone atrophy, and cardiovascular issues.
However, the bigger problem for Artemis II is simply how far the crew will be from home, should something go wrong.
Dr Myles Harris, an expert on health risks in remote settings at UCL and founder of Space Health Research, told the Daily Mail: ‘Space is an extreme remote environment, and astronauts react to the stressors of spaceflight differently.
‘It follows that many of the challenges of healthcare in space are similar to the challenges of providing healthcare in remote and rural environments on Earth.’
Just like an Antarctic expedition here on Earth, the astronauts will have limited medical equipment, unreliable access to expert opinion, and will be days away from the nearest hospital.
If a crew member were to experience a medical problem, these factors mean that small issues can become critical.
3. Heat shield failure
Ed Macaulay, a lecturer in Physics and Data Science at Queen Mary University of London, has voiced his fears about Orion’s heat shield, which bears the brunt of the searing heat during re–entry through Earth’s atmosphere.
The most dangerous moment will occur during re–entry, as Orion’s heatshield is subjected to enormous temperatures due to friction with the atmosphere. Pictured: Orion’s heatshield after re–entry during Artemis I
The heatshield coating is designed to burn away during re–entry, however, NASA found that the coating had chipped and deteriorated far more than expected during Artemis I
Dr Macaulay points out that during Artemis I, large chunks of material were found to have been lost from the heat shield.
Should this happen again on Artemis II, it could expose the crew to ‘dangerously high temperatures’.
‘During the final phase of the Artemis II mission, there’s no backup, no contingency, and no chance of escape,’ Dr Macaulay explained in an article for The Conversation.
‘The four astronauts on board will be depending on a few inches of resin–coated silica to shield themselves from temperatures approaching half that of the surface of the Sun.’
During 2022’s unmanned Artemis I test, NASA found that Orion’s heat shield was cracked and cratered with unexpected damage.
The heat shield material, known as Avcoat, is designed to burn away during re–entry to help dissipate the heat.
However, the damage was well beyond what NASA had expected.
‘Instead of burning away evenly over the whole surface, parts of the Artemis I heat shield were lost unexpectedly in uneven chunks,’ Dr Macaulay explained.
‘This uneven ablation makes modelling the thermal loads of re–entry more unpredictable, and raises the possibility that the Orion capsule could be exposed to dangerous levels of heating.’
Further investigation found that the problem was that the Avcoat layer wasn’t permeable enough, so gases built up in pockets and blasted off entire chunks.
Following the mission, Dr Danny Olivas, a former NASA astronaut who served on review team that investigated the incident, told CNN: ‘There’s no doubt about it: This is not the heat shield that NASA would want to give its astronauts.’
Surprisingly, NASA has decided not to change the heat shield going into Artemis II.
Instead, it has made some important changes to the mission itself.
Instead of ‘skipping’ back to Earth – a technique that sees the capsule act like a stone bouncing on water as it dips and lowers itself into the atmosphere – NASA will use a more direct re–entry model for the crewed Orion capsule.
This should reduce the uncertainty in the heating profile, and will mean less time at peak temperatures for trapped gases to damage the heat shield.
‘[It] also means that the crew will be subjected to increased deceleration on re–entry,’ Dr Macaulay added.
After nine gruelling months in space, Suni Williams (pictured) and Butch Wilmore finally returned to Earth. But shocking before–and–after images show the damage that their unintended stay in space has caused
4. Health problems back on Earth
While Artemis II is considered a short–term mission, astronauts Reid Wiseman, Victor Glover, Jeremy Hansen and Christina Koch can still expect to contend with a series of issues.
Dr Irene Di Giulio, from the Centre for Human and Applied Physiological Sciences at King’s College London, said the duration of the mission means the long–term health risks are ‘significantly reduced’ compared to those who spend months on the International Space Station (ISS).
However, these astronauts will still be exposed to high levels of radiation that can trigger nausea.
‘Space motion sickness could also be experienced as the body needs a few days to adapt. Meanwhile acute fluid shift from the lower part of the body to the head may cause discomfort and swelling,’ she said.
‘Sleep disturbances due to a sudden change in the light–darkness cycle and the use of artificial lighting may be experienced.
‘And mental stress and isolation, especially given the mission demands and living in an enclosed environment, may affect performance.’
Last year, shocking before–and–after images showed the damage that nine gruelling months in space had on astronauts Butch Wilmore and Suni Williams.
Both experienced weight loss and muscle atrophy and appeared significantly older when they finally returned to Earth.
