Engineers look up at the night sky, with its dazzling dot matrix of distant stars, and can’t help but think of the awesome spaceships they can build to get one small step closer. There’s nothing more technologically awe-inspiring than a gargantuan, flame-spewing rocket that looks gravity dead in the eye and says not today.
But there’s a less shiny side of space technology that demands every bit as much engineering attention, according to Dr. Nicole Buckley, Chief Scientist of Life Sciences at the Canadian Space Agency (CSA). Dr. Buckley’s job is to ask that quarrelsome question that complicates the whole spacefaring dream: can humans even survive in space?
“We know that space has profound impacts on physiology, and we're still just trying to understand that,” Dr. Buckley explained when we spoke with her at the recent Discovery 2019 conference in Toronto. “When you think about it, on Earth, we don't actually really know how the whole human body works. So now you're putting it in a completely different environment, and we're trying to figure that out.”
One of the biggest threats is the high radiation that permeates space. Astronauts aboard the International Space Station (ISS) are exposed to the radiation equivalent of 480 chest x-rays during a six-month mission, which increases their risk for cancer and degenerative diseases. The lack of gravity in space is another big issue. We humans are strongly accustomed to 9.81 meters per second per second of downward acceleration, and taking it away can have strange effects on our bodies. In those same six months aboard the ISS, an astronaut’s carotid arteries stiffen as much as they would in 20 years of aging on Earth.
But the problems with space travel go far past the physiological; psychosociology plays a part as well. If we’re ever going to make it anywhere interesting in space, it means a long journey in close quarters with other humans (and not your friends or family, but your co-workers, as Dr. Buckley points out. And she loves her co-workers). The social situations of spacecraft are extreme, and it’s an open question how to keep astronauts sane and happy in their starship cells.
There’s also evidence to suggest that these problems may amplify one another. “We're actually concerned that radiation might make things [e.g., microgravity] worse than they are on their own,” said Dr. Buckley. “Once you put humans in space, it gets really complicated, really fast. And I think that there's a lot we still have to learn.”
To facilitate that learning, we need more data, and that’s where Dr. Buckley comes in. Through collaboration with Canadian scientists, Buckley and her team at CSA organize experiments to learn as much as possible about life in space. For example, At Home in Space is an experiment asking 12 astronauts to evaluate their experiences before, during, and after their missions to the ISS, which will help us understand the mental impacts of space journeys. Another experiment, Wayfinding, is imaging the brains of ISS astronauts to understand how humans can spatially orient themselves without the help of gravity. And to learn how human bone structure is affected by microgravity, MARROW is an experiment tracking 13 astronauts’ bone marrow before and after a trip to the ISS.
The good news is that not all of these crucial experiments are dependent on the ISS; some aspects of space travel can be studied right here on Earth. For example, in one experiment that simulated microgravity, healthy subjects were told to lie in bed for 90 days with their heads tilted six degrees below their feet.
“We [were] able to simulate some of the fluid shifts, some of the muscle loss, some of the bone loss, and some of the neurological changes that can happen in space,” Dr. Buckley explained.
Though these and many more experiments are helping us understand life in space, Dr. Buckley believes that we’re still in the early stages of that understanding. And for good reason: we simply haven’t spent enough time off-planet.
“There have only been about 590 people in space, period,” Dr. Buckley said. “We've had a lot of people on the International Space Station, but that's still pretty close to within our atmosphere, just on the reaches of it. Once you start getting out to outer space, there have only been around 20 astronauts who have been out there, and only for short periods of time.”
We don’t yet have enough data to understand how our delicate carbon cargo holds react to the alien environment of outer space. That’s a big reason why Dr. Buckley is skeptical about the optimistic vision of engineers like Elon Musk, whose company SpaceX plans to send a crewed mission to Mars as early as 2024.
“I think that at this time it would be a very, very risky venture,” Dr. Buckley said. “I know one astronaut who's suggested that the radiation effects might result in blindness by the time you get to Mars, because of radiation damage to the retinas. We don't know what two years are going to do.”
We also don’t know the effect of hopping between Earth gravity, no gravity, and the 0.38g on the Red Planet’s surface. “If you take gravity away for two years or six months, and you put people back even in a limited-gravity environment, that's tough. Because now you have to re-adapt again,” Dr. Buckley continued.
It’s hard to hear about these unknowns, because space exploration is as exciting as it’s ever been since the 1960s. Musk and SpaceX have inspired a generation of engineers to look up, look way up, and our biological frailties are an unpleasant dampener on this excitement. But they don’t have to be. The many challenges can be seen as a call to engineers around the world; a world that, if we answer that call, we may someday leave behind.
“This is why we really need the engineers,” Dr. Buckley beckoned. “What are you going to do with all that extra CO2 when they [astronauts] exhale? What are you going to do about keeping the food nutritious and keeping them safe from radiation? I always say that we don't just need the rocket scientists, but we need the guys who are going to make the toilet that works in space. We need the guys that are going to make sure the cooling systems work, the heating systems work.”