It’s 21st century and we’re yet to travel to other stars. For example, the nearest star is Proxima Centauri, located over 4 light years away. FYI, the Voyager spacecraft, the most distant human objects ever built by humans, would need about 50,000 years to make that journey.
Nobody is going to live that long. We’re going to want to make the journey more speedily. But the problem, of course is that going more quickly requires more energy, new forms of propulsion we’ve only starting to dream up.
With our current technology, it’s less likely that we’re going to make to another star. There are some absurd options like, Create a generational ship, so that successive generations of humans are born, live out their lives, and then die during thousands of year long interstellar journey.
Or can we skip all those years of long journey just by falling asleep and wake up again on another planet? Is human hibernation possible? Can we do it long enough to survive a long duration space journey? This crazy idea arose from animals hibernating themselves for an extended period of time in order to be able to survive over a difficult weather conditions. Animals are capable of slowing their heart rate down to just a few beats a minute.
Humans, after all, don’t naturally hibernate. But a small, eclectic group of scientists is battling nature to trigger artificial hibernation in humans. If successful, they could delay aging, treat life-threatening illnesses, and get us to different planetary system in universe.
How Human Hibernation Works
Therapeutic hypothermia is a type of treatment used for people who have a cardiac arrest. It deliberates reduction of the core body temperature, typically to a range of about 32° to 34° C (89.6° to 93.2° F) in patients who don’t regain consciousness after return of spontaneous circulation following a cardiac arrest.
In 1999, a radiologist Dr. Anna Bagenholm fell into a frozen stream while skiing in Norway. By the time she was retrieved, she had been under ice for over 80 minutes. By all accounts she was clinically dead no breathing & no heartbeat. Her body temperature dropped to an unprecedented 56.7 °F (13.7 °C).
When doctors gradually warmed her blood, her body began to heal slowly. Few hours later, her heart started pumping. By day 12, she opened her eyes and eventually recovered fully.
Bagenholm’s case is just one hint that humans have the ability to recover from a severely depressed metabolic state.When humans freeze, ice crystals form in our cells, rupturing them permanently. There is one line of research that offers some hope: cryogenics. This process replaces the fluids of the human body with an antifreeze agent which doesn’t form the same destructive crystals.
Scientists have successfully frozen and then unfrozen 50-milliliters (almost a quarter cup) of tissue without any damage.
For years doctors have been working on Therapeutic Hypothermia, lowering body temperature by a few degrees for several days to help keep patients with brain injuries or epilepsy in suspended animation. This rapid cooling helps preserve tissues that have been cut off from blood supply, so they require less oxygen to function. But the trick is to not make them so unconscious that they die. It’s a fine line. The results have been pretty amazing so far. People have been kept in this torpor state for up to 14 days, going through multiple cycles.
The promise of therapeutic hypothermia is so great that SpaceWorks Enterprises delivered a report to NASA on how they could use this therapeutic hypothermia for long duration spaceflights within the Solar System.
Although the flight into space would only last a few months, putting astronauts into an inactive state would result in reduction in their metabolic rate of 50% to 70%. Less food, space, cargo required. Also the astronauts wouldn’t need to move around, so you could keep them nice and snug in little pods for the journey.
Current plans for sending colonists to Mars would require 40 ton habitats to support 6 people on the trip. But according to SpaceWorks, you could reduce the weight down to 15 tons if you just let them sleep their way through the journey. And the savings get even better with more astronauts.
So far the project made it to the second funding round, which will further investigate this technique for Mars missions, and how it could be used even farther out in the Solar System.
In addition, the European Space Agency has also been investigating human hibernation, and a possible way to enable long duration spaceflight. They’re planning to test out the technology on various non-hibernating mammals, like pigs. If things go well as planned, we might see the Europeans pushing this technology forward.