'Project Hail Mary' Sparks Debate on Interstellar Travel Survival

United States - Ekhbary News Agency

'Project Hail Mary' Sparks Debate on Interstellar Travel Survival

The fictional narrative of Andy Weir's novel, 'Project Hail Mary,' has ignited widespread curiosity about the practicalities of human survival during voyages to interstellar space. The fates of the astronauts in the book, which has also been adapted into a film, highlight the profound risks associated with such extended journeys, prompting scientists and experts to contemplate the biological and technological solutions that might one day make these seemingly impossible missions a reality.

At the core of Weir's story lies a critical question: how can astronauts endure the vastness of space for years, even decades? The novel posits medically induced comas as a primary method for long-duration space travel, with the astronauts entering a state of suspended animation for up to four years. Dr. Haig Aintablian, an emergency physician and flight surgeon who directs UCLA's space medicine program, acknowledges the theoretical appeal of this concept. "How cool would it be if you went to sleep a few hours after launch, and you woke up right as you arrived on the planet or the celestial body that you’re approaching?" he muses. However, he critically adds, "I don’t think keeping the human alive and in a comatose state is necessarily the best option."

Aintablian elaborates on the physiological drawbacks of prolonged immobility. "The human body is not designed to just be a stagnant blob," he states. Astronauts in a comatose state would be susceptible to severe health complications. Chief among these are the increased risks of life-threatening blood clots due to lack of movement and debilitating muscle atrophy from disuse. Furthermore, the necessity of invasive tubes and devices to sustain a comatose individual introduces significant risks of infection, posing a substantial challenge in the sterile environment of space travel.

These inherent dangers compel a broader inquiry into alternative methods for enabling interstellar travel. Aintablian suggests cryopreservation, or freezing, as a potential solution. "When the day comes where you could freeze someone and just thaw them, you would have solved the issue," he posits. However, this approach faces considerable scientific hurdles. It remains unknown whether human bodies can withstand the rigors of freezing and thawing as effectively as certain animals, such as the wood frog, which can survive being frozen. Integrative biologist Matthew Regan of the University of Montreal points out that human hearts have critical functional limits, typically operating poorly below approximately 28 degrees Celsius (82.4 degrees Fahrenheit). While some individuals have survived temporary, deeper body temperature dips, sustaining this for the years required for interstellar journeys presents a fundamentally different challenge.

Another avenue being explored is hibernation, or a state of induced torpor. Small mammals that hibernate, like the Arctic ground squirrel, drastically slow their metabolism during torpor, lowering their body temperature to below freezing. Regan describes their metabolic rate as "2 percent of what it usually is. They’re just barely ticking over. It’s like pilot light levels." Hibernating bears, while less extreme, also reduce their metabolic activity and lower their body temperature by only a few degrees to around 31-32 degrees Celsius (88-90 degrees Fahrenheit). Crucially, torpid animals remain largely sedentary but do not develop the blood clots or muscle atrophy seen in bedridden humans.

The potential for humans to achieve a similar metabolic slowdown could revolutionize space travel. If humans could dial back their metabolism even slightly, as bears do, space voyages would require substantially fewer resources for sustenance, life support, and medical care. Torpor might even offer a degree of protection against ionizing radiation, a significant hazard for deep-space explorers. However, hibernation might not be a continuous state for the entire journey. Ground squirrels and other hibernators typically rouse periodically, rewarming their bodies and moving around. The precise reason for these awakenings is still debated, but neurochemist Kelly Drew of the University of Alaska Fairbanks suggests it may be crucial for muscle regeneration and maintaining brain health. This implies that humans might also need periodic awakenings to keep their brains sharp, muscles strong, and to consume nutrition.

Hibernation biologist Hannah Carey of the University of Wisconsin–Madison raises an additional concern related to metabolic states and body composition. She notes that fattening up astronauts before a long hibernation period might be counterproductive. Bears that accumulate significant body fat before hibernation experience a temporary rise in cholesterol levels, which then normalize as they lose weight. In humans, however, such a cholesterol spike could pose a serious risk of heart disease. Carey also recounts observations of captive ground squirrels that became overweight and died mysteriously during hibernation, suggesting that excess body fat might, in some circumstances, be detrimental to the survival of hibernating animals.

Ultimately, these biological considerations do not fully explain the astronaut deaths in 'Project Hail Mary.' When asked about the fictional deaths, Andy Weir clarified that they were not a biological failure but a "tech failure." He explained, "I mean, being in a coma for four years is a dangerous proposition in the best of times. So a small tech failure can lead to catastrophic results. Which it did in this case."

The narrative of 'Project Hail Mary' continues to serve as a compelling thought experiment, pushing the boundaries of our understanding of human endurance and the scientific innovations required for humanity's potential future among the stars.

Ekhbary News Agency