Through Hardship To The Stars

‘Per aspera ad astra’. This is the phrase adopted as a statement of intent by space agencies, both real and fictional, that originates in Virgil’s Aeneid. But exactly what kinds of hardship will the human body have to endure to colonise the cosmos? Prof Christopher E Mason has been studying astronauts’ reactions to life in space and reveals to Ian Taylor how we might adapt to overcome the challenges we face

- Ian Taylor

When Scott Kelly came back to Earth after 340 days in space, it felt like his skin was on fire. Not on re-entry, but later, when he tried to sit down, get dressed, or move. Spending close to a year in microgravity will do that to you; aboard the International Space Station (ISS), Kelly’s skin got used to feeling no weight and having nothing touching it.

Like other astronauts, he floated around the ISS with little need for furniture. He didn’t wear shoes and even his clothes drifted around his body instead of hanging from it. So when he came home, a shirt sleeve bearing down on his arm under the pull of Earth’s gravity was alien, painful even. As Kelly himself said in a post-flight press conference: “Adjusting to space is easier than adjusting to Earth…”

Since the year-long mission ended in 2016, Kelly has become a guinea pig for scientists studying what happens to the human body when it ventures beyond Earth’s atmosphere. Even among astronauts, he’s a rare case. Not only did he spend the best part of a year in orbit, but Kelly has an identical twin brother, Mark. It gave NASA an unprecedented opportunity to study the physiological, molecular, and cognitive effects of long-term spaceflight.

Scott went to space. Mark, the perfect control subject, stayed on Earth. The brothers are both retired astronauts now, but their contributions to the landmark Twins Study continue and have produced a wealth of information about how space affects the heart, the microbiome, the immune system, and more.