What risks do humans face in space?

Aerospace medicine expert chats about the challenges of interplanetary travel.

Credit: Nisian Hughes/Getty Images.

It was quite the job ad when NASA started looking for astronauts for its Moon to Mars mission. They’re searching for the first woman and next man to walk on the Moon – and maybe send them onto the Red Planet.

One of the first requirements for future space travellers is the ability to get along with crewmates, Dr Gordon Cable says. He’s an associate professor in aerospace medicine at the University of Tasmania, and his job is to look at the hazards and risks humans face in space.

He says they’ll need to deal with the distance, the isolation, and the “Earth-dependence” – those already on the International Space Station at least can still see our pale blue dot.

So selection and training will be key, particularly for Mars, where a small group of humans will have to get along and work together for months.

“You don’t want people who are overly gregarious all the time – but equally you don’t want people who are shy and retiring and can’t make any decisions,” Cable says.

“We need that balanced personality and people who work well as a team.

“I often say…going to Mars is like being trapped in a caravan with three of your best mates for three years. If you can make it through that, you can make it through anything.”

Then there are the physical challenges. Being in microgravity or partial gravity affects how the cardiovascular system works and can leave bones weaker. Radiation is a “potential showstopper”, too.

Once humans leave the “protective bunker” of the Earth’s atmosphere they’re out in the universe, which is bathed in cosmic radiation. That poses a cancer risk and a reproductive risk.

It means anyone who gets on that interplanetary craft may only be able to go once. The “career exposure” to radiation is too great a risk.

That’s just the start, Cable says. Once they return, they’ll need to be reconditioned, to “get their Earth legs back”.

Australia, he says, is in a good position to contribute to the Moon to Mars mission. “We have an international reputation,” Cable notes, thanks to our experience in extreme environments and our achievements in medical research, including in radiation exposure.

In a way, it’s the challenges that make the adventure worth it. What is learned about supporting astronauts will help Earthly healthcare more broadly, particularly for remote and Aboriginal communities, and even aged care.

For example, researchers are looking at biomarkers, such as putting sensors under the skin to detect dehydration early – that’s important for astronauts in extreme environments, and in aged care where people can become dehydrated very quickly.

“To have a wearable monitor that can feed data to a system that monitors hydration levels and warns that hydration isn’t adequate can lead to early diagnosis and intervention,” he says.

“We always think of the duality between space and Earth, Earth and space…we make sure we get spinoffs to help the Earth population as well.”

Source: Cosmos