A team of scientists say they may have discovered a way of counteracting the bone and muscle deterioration that astronauts experience in space.
The technique involves creating a 'digital twin' that can help scientists monitor the relationship between an astronaut's movements and their muscle activity.
More on human spaceflight
It could be of major use, the scientists say, as astronauts begin spending longer periods in space, and as the first crewed mission to Mars becomes more of a reality.
The problem with spaceflight
Humans didn't evolve to live in space. We evolved to live on Earth, with Earth's gravity effectively pulling us down towards the ground.
And when humans spend a lot of time in a weightless environment, our bones and muscles begin to deteriorate.
This is a well-recorded phenomenon, and is why, for example, astronauts on the International Space Station need to exercise for 2 hours a day.
Even the Artemis II astronauts, whose journey around the Moon and back will last just 10 days, have a fitness regime built into their schedule.
So if relatively short journeys into space are enough to cause major issues in the human body, how can we expect humans to survive the long journey to Mars, then be able to walk about on the Red Planet once they get there?
A solution in AI?
Scientists at West Virginia University in the USA say they're developing computer models powered by Artificial Intelligence to help treat and prevent the challenges of astronauts living in weightless environments for long periods of time.
Valeriya Gritsenko and Sergiy Yakovenko are associate professors in the departments of Human Performance and Neuroscience in the WVU School of Medicine and WVU Rockefeller Neuroscience Institute.
They point to a growing likelihood that humans will be spending longer periods in weightless environments, like the next generation of space stations, NASA's Lunar Gateway at the Moon or even crewed missions to Mars.
The scientists say their technology will be able to create a 'digital twin' for each astronaut, showing how an individual adapts to the weightless environment.
It can then stipulate what that astronaut needs to do to counteract the effects of weightlessness like muscle loss and bone density, but also visual and neurological changes.
"Currently, each astronaut requires a very large Earth-based team that looks at his or her vitals and modifies exercise plans or otherwise intervenes," says Yakovenko.
"As we travel farther away from Earth, that kind of support will not be available, so we are researching alternatives.
"When astronauts return to Earth, they say what they miss the most in space is the ability to walk.
"Even though they exercise a lot, they cannot maintain the correct coordination in microgravity. So, if we want to travel as far as Mars, the astronauts’ coordination will be disrupted in a profound way.
"Right now, they might make it to Mars, but by the time they set foot on the planet, they would probably fall down. We don’t want that, so we are developing a non-invasive way of observing astronauts as they go about their business."
How it works
The team say their research involves studying human volunteers on Earth completing various simple physical tasks.
They use motion capture and sensors to track the volunteers' motions and record how their muscles move.
"Our virtual reality software is similar to the artificial physics engines used for gaming or movies, which simulate the movement of virtual characters in a way that looks natural," Gritsenko says.
"Given factors like a person’s size, weight and muscle action, we can run simulations to see what kind of forces people would need to make certain movements, and that predicts what astronauts would experience in orbit or in a zero-gravity environment."
They say that, if adopted by space agencies, their AI models would monitor an astronaut’s exercise routine before launch, during the mission and after returning to Earth.
The system, they hope, could spot subtle early signs of trouble before they become bigger problems.
"The model can then tell the astronaut, 'Exercise more, or use heavier weights or else you might be at risk of some muscle loss'," Gritsenko says.
"When they come back to Earth, the model would also have a reliable estimate of how much they have de-conditioned in orbit and could develop a routine to help them cope with problems like balance issues or ‘orthostatic intolerance,’ when they lose consciousness because blood is not pushed into their heads quickly enough when they stand up."
The project has been supported by a $750,000 grant from NASA
And the team say the AI could be used on Earth, too, in rural telemedicine, for example, which is when technology is used to provide medical services to remote populations around the world.
"People can get more out of telehealth if we use these digital twin tools for early detection of concerns like motor deficits, balance problems or even early neurodevelopmental delays," Gritsenko says.
"There are lots of parallels here between spaceflight de-conditioning and muscle and neural motor control in people who are very sedentary — for instance, those who are older or pregnant people who have been on extended bed rest."
