Astronauts in the movies certainly look comfortable enough drifting about in billowing polo shirts and tracksuit pants, but is casual sportswear really appropriate for life in space?
The evidence suggests it isn’t, says Human Aerospace head of flight medicine, Dr Gordon Cable.
Bone and muscle loss is only the most obvious effect of zero gravity, but astronauts also experienced real problems with their vestibular (balance) system.
“You can see the effects of microgravity when they come home,” he says. “They wobble all over the place. They can’t drive. They can’t walk for quite a few days. They need weeks of reconditioning to get their balance back.”
That’s after the regular six-month stay in orbit. But even Space Shuttle astronauts in space for a week to 14 days had real problems.
“The pilots couldn’t really land the Shuttle properly,” Cable says. “Studies showed that in something like 20 per cent of all landings, touch-down speeds were off-nominal – likely because the pilots’ sense of direction and balance were all over the place.”
Replacing casual sportswear with new ‘spacewear’ may help reduce the problem. “We’re not in the big gas-pressurised suit business,” says the University of Adelaide-based Cable. “We’re looking more at everyday wear that can act as countermeasures for some of the physiological problems astronauts encounter.”
It’s called bioastronautics. And aerospace engineering, medical, textile science, biology and nursing experts are pooling their talents to produce skinsuits capable of carrying the human body through the rigours of long-duration spaceflight.
They must be simple. They must be self-contained. They must be adaptable.
“We need something that can be donned and doffed easily,” Cable says. “That could be quite a chore because it also needs to be tight fitting”.
Humans aren’t designed to live without weight.
“When we go to space, some 60 to 70 per cent of us will get some degree of motion sickness in the first 72 hours,” says Cable.
Their eyes are telling them there is movement. But their body insists nothing’s happening.
The physical fallout of this disorientation is just the first sign things aren’t right.
As time passes, more effects accumulate.
“One thing we do know from the International Space Station is that we really don’t know everything about human spaceflight,” Cable says. “Stuff turns up all the time that we haven’t seen before”.
One example is venous thrombosis – in the jugular vein.
The first time that was ever documented was recently aboard the ISS.
“The occurrence was entirely a surprise to medical experts,” says Cable. “It left everyone wondering whether or not these clots had been occurring in the upper body in space for a long while, but not recognised as such.
“So we hope to provide some countermeasures in flight to support the body’s reflexes for when they reach the Moon or Mars, and when it returns to Earth again.”
Human Aerospace is researching three different styles of suit to address these issues.
One addresses orthostatic intolerance. It’s the low blood pressure effect experienced when you stand up too quickly after resting. It’s also linked to conditions like deep vein thrombosis.
Another tackles somatosensory problems. That’s about tricking the brain into believing the body is being influenced by gravity.
Finally, it’s conducting conceptual work into the viability of skin-tight compression suits replacing the complex bulk of pressurised extra-vehicular activity (EVA) spacesuits. They could be more mobile. They could be safer. If they can be made to work.
The concept of a “G-suit” is nothing new. They entered widespread use in World War II to stem the rush of blood downwards in the body in aerial combat.
Graded compression garments are used in post-surgery recovery, to prevent deep vein thrombosis and for burns recovery.
But adapting them for astronauts isn’t easy.
“The problem with them is the fitment,” says Cable. “They need to be adjustable.”
In space, your body changes.
Spines elongate. Legs shrink. Some spots bulge as others contract.
“Pretty quickly, these suits don’t work as effectively as they should,” he says.
Somatosensory wear introduces another set of challenges.
They must create resistance to specific ranges of movement. Lift your arm, for example, and it will encounter gravity-like pressure. Let it relax, and it will flop back down to your side.
This entails carefully crafted layers of elastics and tensioned materials. Such an interweave of force and counterforce must be balanced and applied with pinpoint precision.
Now, instead of focusing on bone and muscle health, NASA has prioritised the need to preserve astronaut balance and posture systems.
“We’re doing it collaboratively now with another company called Prism Neuro, who are developing a sock, for want of a better word,” Cable says.
That “sock” is tailored to stimulate the sole of the foot in a way interpreted by the brain as the pressure of standing up under gravity.
“So we’re trying to integrate that technology with our graded compression garment to provide a support for all these postural reflexes. There hasn’t really been anything like it before.”
Human Aerospace Chief Engineer and CEO, Dr James Waldie says travelling to Mars will be the adventure of the 21st century: “Australia can and should play a niche role as we have unique medical capability to support human life during long duration space travel. We’ll also be using our experience and technology of such missions to stimulate new medical treatments for us here on Earth too.”
Your average Martian won’t likely wear polo shirts.
But a Red Planet wardrobe is still a long way off.
“Honestly, we don’t know much about the body’s response to partial gravity in terms of 1/6 gravity on the Moon and 3/8ths gravity on Mars,” says Cable. “So whether or not skinsuits are going to be required in those environments is a little unclear.”
But we know we’ll need them to get the astronauts there.
“It’s only three days to get to the Moon, but they plan to spend three to six months on the Lunar Gateway station in orbit before going down to the surface. With Mars, we’re talking eight months just to get there.”
Until then, the suits will need to undergo rigorous testing.
On unrigorous test subjects.
They’ll get paid to spend weeks in bed, on a slightly head-down incline.
That’s the best way to simulate the effects of zero gravity here on Earth.
The idea is to measure the effectiveness of the graded pressure suits, but also to identify any problems.
The somatosensory suit, for example, may have unintended consequences. “It makes you feel like you’re standing up constantly,” says Cable. “And that’s not something the body likes to do when sleeping, for example.”
Then there’s how long and often such suits need to be worn. There’s no space for a laundry service between worlds.
“That’s really the subject of some further work down the road, once we’ve proven the physiology of these suits doing what they’re meant to do”.