Thursday, March 10, 2022

Interstellar travel in suspended animation

Most of the problems mentioned at the end of the previous post would disappear if the generational journey were combined with another scientific advance that does not seem, at first glance, impossible: the conservation of human beings in a state of latent life for very long periods of time. This state, which resembles what many living beings do when environmental conditions are unfavorable, is called hibernation when it is a response to cold, and aestivation when it is used as a defense against heat and dry seasons.

Under the current conditions of science, human hibernation is not feasible. It is true that it is possible to reduce the vital rhythm through the application of low temperatures, a technique that is being used in surgery to carry out complex or delicate operations, but the total suspension of vital activities is always transitory and limited to a short period of time, usually measured in hours.

If human beings could be kept in a state of indefinite and reversible hibernation, interstellar journeys could be made under the same conditions applicable to generational travel, but future colonists could travel in a state of latent life. Thus, the same individuals who began the journey would reach the end; it would not be necessary to control the population or preserve long-term knowledge; there would be no problems of psychological adaptation to unknown environments. Finally, the energy expenditure would be much smaller, since humans would consume very little in hibernation.

Although its initial goal is not a trip to the stars, but to Jupiter, the film 2001 A Space Odyssey uses this method.

If the spacecraft operation and life support equipment were fully automated, it would not be necessary to maintain a human crew during the journey. Otherwise, it would be necessary to perform guard shifts. Many more people (perhaps 100,000) could be carried on such a voyage, since in hibernation they would need little space and supplies, and more energy would be available. If the shifts were made up of four people, the duration of each shift could be two years for a trip of fifty thousand years, which would advance the biological age of the colonists very little.

Another form of suspended animation that has been used in imaginative literature and serious scientific journals involves freezing embryos, rather than adult human beings. In fact, this technique is far more advanced for embryos. When the target of the journey was reached, the embryos could be thawed and developed in automatic incubation machines (which do not yet exist), and then reared, either by a small number of adults transported in the same way, or by automatic machines (which also do not exist). I myself have used this solution in one of my science fiction novels: The History of the Earth-9 Colony.

It is evident that both the generational journey and the hibernation journey have no return: once started, no participant can return to Earth. Either of the two methods can be used if the objective of the trip is the dissemination of human beings to stars not far from the solar system, but the problem of increasing our knowledge regarding other planetary systems would not be solved, as those who go there will hardly be able to send us information in a long time. For this, it would be necessary to resort to other methods that make the return of the astronauts possible.

The same post in Spanish

Thematic Thread on Space Exploration: Previous Next
Manuel Alfonseca

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