Imagine waking up, groggy and bearded, on a spaceship light years from Earth. That’s how Ryland Grace, played by Ryan Goslingwakes up in the new space drama Hail Mary Project. As the audience soon learns, Grace, a middle school science teacher, has apparently been sent on a mission to save the sun from death.
The movie is largely science-basedfrom the names of the stars (Tau Ceti is a real star) to its depictions of artificial gravity. Aside from fuzzy quantum physics and fictional sun-eating microbes called Astrophage, “everything else just follows established physics and science,” said Andy Weir, author of the novel. Hail Mary Project and producer of its film adaptation, in a recent interview with Scientific American.
Does this include the opening scene of the film? According to science, yes and no.
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In the book, Grace understands that her sleeping state is akin to a medically induced coma, or a form of “suspended animation.” He is connected to an IV and feeding tubes and receives “constant medical care” from an onboard robot. “Everything a body needs,” Weir writes in the book.
But putting someone in a pharmacological coma for long-term space travel would be tricky, says Matteo Cerri, an associate professor of physiology at the University of Bologna in Italy. For one thing, it wouldn’t significantly slow the body’s metabolism, meaning it might not change the body’s needs for food or oxygen. And above all, “at a certain point, the drugs become toxic,” explains Cerri.
However, it would be possible to slow down the metabolism, he says, in a way induced hibernation-like stateor “synthetic torpor”. Many animals, such as bears and hamsters, slow their metabolism and use less oxygen than normal during a state called torpor. And other animals, like ground squirrels, enter a prolonged form of torpor known as true hibernation. Lower body temperatures and less demand for energy mean they don’t need to eat or drink, sometimes for months, Cerri says. “Life moves forward but very slowly. It’s like we’re slowing down the clock of life, and each second lasts longer,” he explains.
In humans, “in theory, synthetic torpor would work. I’m convinced of it,” Cerri says. He currently chairs a research group for the European Space Agency studying how to induce human hibernation or torpor during space travel. Being able to enter such a state in space has advantages, such as lower metabolic demands and potentially longer lifespan, and can provide protection from radiation, Cerri explains, in part because lower oxygen levels in tissues can increase resistance to radiation. “Radiation is the number one problem in space exploration,” he says. “There is no solution at the moment.”
No researcher has yet successfully induced hibernation in a human, but Cerri and his colleagues have shown that it is possible to induce torpor in animals that do not naturally enter this state: rats. By injecting drugs into part of the brainstem, the researchers “tricked” part of the rat’s brain to induce synthetic torpor. But for safety reasons, it is not yet possible to reproduce the experiment in humans.
Another potential strategy often described in science fiction:Stranger, Avatar, Futurama, and more, it’s “cryosleep“, basically freezing a person’s body to thaw later without killing them somehow in the process. Again, no one has done this in real life. But some scientists say it’s possible, at least in theory.
“I believe that reversible human cryostasis will become technically possible,” says Alexander German, a researcher in molecular neurology at the Friedrich-Alexander University of Erlangen-Nuremberg in Germany. “If you look at nature, it’s not a completely foreign concept,” he says. tardigrades, he notes, can “vitrify” or turn into a vitreous substance, while Siberian salamanders can survive frozen for years in permafrost, and Arctic Ground Squirrels can survive for weeks in subzero body temperatures. This raises “the question of why humans should not possess latent biological potential for this if we apply the right methods,” German says.
In a paper published in early March, German and colleagues brain activity successfully recovered in mouse brain slices after vitrification at –196 degrees Celsius. “This proves that reversible cryostasis may be possible in principle, although we still have a long way to go in practice,” says German.
The risk with cryonics is that when water turns to ice, it expands to take a crystalline form like a “blade in a balloon,” Cerri explains, and can burst cells. If scientists ever solve this problem, among others (notably the toxicity of vitrification chemicals), and make cryogenic sleep viable, “it will be revolutionary, because it will allow a very, very long journey” into space, he says.
Surprisingly, a detail that science fiction films, notably Hail Mary Project, Often getting it wrong about suspended animation is waking up, Cerri says. “What’s wrong with all films, in general, is the excitement. The awakening is too immediate,” he explains. In theory, to return safely from induced hibernation, or even cryogenic sleep, the body and mind would likely need hours or days to reverse the torpor-induced changes. “Every organ has to ‘go back to work,’” Cerri says.