Spaceflight has always fascinated me. While long distance spaceflight looks so routine in science fiction shows, the reality is much different as we have yet to conquer the complications surrounding long duration deep-space flight. One issue is how to feed astronauts traveling long distances as we do not yet have replicator technologies. If we did, I would have coffee whenever I wanted it. In a new article published in Physiology, researchers discuss recent advances in understanding the physiology of naturally hibernating animals that may help make long duration spaceflight a reality.
If placing humans into a state of synthetic torpor were possible, it would alleviate many of the concerns surrounding long spaceflights including psychosocial stresses as well as issues related to food storage, waste removal, the demand for oxygen, adequate living spaces, etc.
Modern medicine already has the ability to induce a torpor-like state in humans by lowering a patient’s body temperature. The limitations of this technique is that it often necessitates mechanical ventilation and therefore must be closely monitored to avoid cardiac arrest and infection and would therefore not be the best option for a space mission. Another method that researchers are exploring is to find a way to mimic the natural process of hibernation in animals.
Natural hibernators present a unique model for researchers to learn about how to safely undergo hibernation. At the onset of hibernation, body temperature declines to about 0°C and metabolism diminishes…without resulting in organ damage. One way they survive this long term stasis is by packing on fat tissue, which the animals can use for fuel during hibernation – avoiding the need to eat. While surviving body temperatures close to zero for a human seems incompatible with life, we do share similarities in how our brains rest at night. While we sleep, metabolism and body temperature also drop and our brains enter a state of slow-wave sleep, similar to entering hibernation. Researchers are hoping to be able to perhaps deepen this process to create a state of synthetic hibernation in humans.
Nordeen CA, Martin SL. Engineering human stasis for long-duration spaceflight. Physiology. 34(2): 101-111, 2019. https://doi.org/10.1152/physiol.00046.2018