Hibernating astronauts could be the most cost-effective way to save money on missions and cut spacecraft weight by a third, while also keeping the crew healthy on the way to Mars. According to an ESA paper, human hibernation is no longer science fiction and in the near future it could become a "game changer" in space exploration.
When preparing for a return trip to Mars, space engineers estimate about two years of food and water for the crew. We are talking about 30 kg per astronaut per day. “And this is only on a logistical level. Also consider radiation issues and those related to mental and psychological aspects,” he says Jennifer Ngo Anh, ESA research coordinator.
Hibernating astronauts? Hibernate to travel
Hibernation-induced torpor is a state of rest that lowers an organism's metabolic rate. This “suspended animation” is a typical method of animals trying to save energy.
A reduction to 25% of a crew's normal metabolic levels would reduce the quantity and size of supplies for a long-term mission. Hibernating astronauts would also reduce the boredom, loneliness and aggression that the stress of traveling as "recluses" brings with it.
But can it be done? The concept of mimicking torpor and hibernating people to treat diseases dates back to the 80s. Using therapeutic numbness to reduce a patient's metabolism during long operations is a common procedure for doctors. However, this is still not what is needed. New ongoing studies could provide what is missing to obtain a more effective technique.
Don't wake the bear
Animals seek shelter from the elements and survive on little food or water during periods of extreme cold and drought, lowering their heart rate, breathing and other vital functions to only a fraction of their normal lifespan as their body temperature drops close to room temperature. Tardigrades, frogs and lizards are excellent examples of animals that can 'hibernate' their functions.
But you know the best model: it is that of the bears. A body mass comparable to ours, a body temperature that rarely drops below ours. During hibernation, the bears retreat to their burrows and spend 6 months still and fasting. Try to do it yourself. A human would suffer severe muscle wasting, loss of bone strength and risk of heart failure.
A bear comes out in the spring very healthy, losing only a little muscle mass: he recovers everything within three weeks. Hibernating its functions protects it from tissue and bone damage. It protects it from atrophy. How the hell does he do it?
Lower testosterone levels appear to favor mammalian hibernation: estrogen has a strong influence on energy metabolism.
“The very specific and different balance of hormones in females or males and their role in regulating metabolism suggest that women may be better candidates,” he says Alexander Chouker, professor of medicine at Ludwig Maximilian University of Munich, Germany.
Hibernate before staying
What would the "beds" be like for a trip to Mars? In the ESA report, engineers suggest creating soft-shell capsules with adjustable settings for light hibernation, such as a quiet environment with few lights, low temperatures (less than 10°C) and high humidity. Wearable sensors would monitor posture, temperature and heart rate.
Each capsule must be surrounded by containers of water that act as a radiation shield. “Hibernating astronauts will actually help protect them from the harmful effects of radiation during deep space travel by limiting cellular damage caused by high-energy particles outside the Earth's magnetic field,” adds Choukér.
Hibernation, or “suspended animation,” was once the realm of science fiction: It could become a significant factor in long-distance exploration in the future. For this reason it is already being studied as a potential "enabling technology" for space travel.
The assumption is that to hibernate astronauts they are given a drug to induce 'torpor'. Just like bears, astronauts should also make some extra 'reserves' of fat before the procedure: eat lunches. Once you go to bed, who would take care of anomalies or emergencies?
