‘Project Hail Mary’ made us wonder how to survive a trip to interstellar space

Editor’s note: This communicative contains ray spoilers for Project Hail Mary.

I person agelong puzzled complete thing successful Andy Weir’s 2021 book Project Hail Mary: Why did 2 of nan 3 fictional astronauts dice during an interstellar trip? 

It mightiness beryllium because Weir put his travelers into four-year-long medically induced comas, says Haig Aintablian, an emergency expert and formation surgeon who directs UCLA’s abstraction medicine program. 

“How cool would it beryllium if you went to slumber a fewer hours aft launch, and you woke up correct arsenic you arrived connected nan satellite aliases nan celestial assemblage that you’re approaching?” But, he says, “I don’t deliberation keeping nan quality live and successful a comatose authorities is needfully nan champion option.”  

After all, “the quality assemblage is not designed to conscionable beryllium a stagnant blob,” he says. Comatose astronauts would beryllium successful threat of deadly humor clots and debilitating musculus wasting from inaction. Infections stemming from tubes and devices required to support a comatose personification live besides would beryllium risky.  

So, I wondered, what different ways mightiness group past interstellar travel? 

Frozen, Aintablian suggests. “When nan time comes wherever you could frost personification and conscionable thaw them, you would person solved nan issue,” he says.  

But nan problem whitethorn beryllium much than technological. No 1 knows if quality bodies tin withstand nan physiological rigors of freezing and thawing nan measurement wood frogs do. Human hearts don’t usability good beneath astir 28° Celsius, says integrative biologist Matthew Regan of nan University of Montreal. Some group person survived deeper assemblage somesthesia dips but only impermanent ones, he says, not nan years it would return to recreation to a distant star.  

Maybe hibernating our measurement to nan stars is nan answer.  

Some mini mammals that hibernate, for illustration arctic crushed squirrels, driblet their assemblage temperatures to beneath freezing during torpor, erstwhile nan rodents’ metabolism drastically slows. “It’s 2 percent of what it usually is,” Regan says. “They’re conscionable hardly ticking over. It’s for illustration aviator ray levels.”  

Hibernating bears prevention little energy, dropping their assemblage temperatures only a fewer degrees to 31° C aliases 32° C (around 88° to 90° Fahrenheit). Torpid animals are sedentary but they don’t create humor clots and their muscles don’t atrophy, dissimilar bedridden humans. 

If humans could dial backmost our metabolism moreover a tad for illustration bears do, abstraction voyages would require less resources to support nan unit fed, patient and happy. Torpor whitethorn moreover thief protect against ionizing radiation, a large problem for abstraction travelers, Regan says.  

But it astir apt wouldn’t beryllium imaginable to snooze nan full trip. Every mates of weeks, crushed squirrels and different hibernators rouse, rewarming their bodies and moving around. No 1 is judge why. It whitethorn beforehand musculus regeneration and thief nan encephalon enactment healthy, says neurochemist Kelly Drew of nan University of Alaska Fairbanks.  

Humans besides whitethorn request to aftermath up to support their brains crisp and muscles strong. And to eat. 

That’s because it mightiness not beryllium a bully thought to fatten up astronauts earlier nan large trip, says hibernation biologist Hannah Carey of nan University of Wisconsin–Madison. Bears that battalion connected pounds earlier hibernation create precocious levels of cholesterol; nan bears retrieve arsenic their weight dwindles but successful humans, that broadside effect mightiness put astronauts astatine consequence for bosom disease.  

Some captive crushed squirrels successful Carey’s laboratory sewage roly-poly quickly but past died mysteriously during hibernation. “They still had a batch of assemblage fat connected them. So it’s not that they were moving out,” Carey says. Perhaps their hearts couldn’t return nan stress, she suggests. 

Still, nary of that explains why nan astronauts died successful Project Hail Mary. With nan movie adjustment headed to theaters successful March, I asked Weir what happened. Their deaths weren’t a nonaccomplishment of quality biology, he says. “It was a tech failure. I mean, being successful a coma for 4 years is simply a vulnerable proposition successful nan champion of times. So a mini tech nonaccomplishment tin lead to catastrophic results. Which it did successful this case.”