If you have ever watched a science fiction movie involving interstellar travel, you have been exposed to the idea of cryosleep.
The term “cryosleep” comes from the Greek word for cold – “krýo” and “sleep”. As the name suggests, the idea behind cryosleep is to freeze the body to sub-zero temperatures to preserve it and then thaw it after a period of time.
The technique of freezing something to preserve it is not something new as it is utilized to preserve seeds and specimens all around the world. But applying this to living, breathing creatures is what has baffled scientists for years.
Though this concept has its roots in science fiction, very real research is currently in progress to bring it to reality.
Road to Immortality
The idea behind cryonics was first introduced by Prof. Robert Ettinger(aka the father of cryonics) in his book “The Prospect of Immortality” in 1964. Motivated by a mid-life crisis and a growing awareness of his own impending death, Ettinger wrote and privately published a preliminary version of his book in 1962 which later made its way to a major publisher. Ettinger believed in preserving one’s body after death so that they could be resurrected once medicine and technology were advanced enough.
This was a crucial step in getting the ball rolling for research on cryosleep as before that the concept was not taken as seriously. Ettinger’s book was praised for its scientific approach and concrete ideas following which some institutes were founded to pursue the field of cryonics. But, unfortunately, they were unable continue their research due to failures in the early attempts of cryopreservation and consequently, companies going bankrupt.
Ettinger founded The Cryonics Institute in 1976 with a fully functional cryonics facility in Clinton Township, Michigan. The institute is operating to this day where Ettinger, his mother, and his first and second wife currently reside in -195oC cryochambers.
The institute primarily works on cryopreserving bodies after death in the hopes of reviving them one day in the near future.
Freezing the body after death is relatively easy. The real challenge is resurrecting the body and returning it to its previous healthy state ,and equally as challenging is preserving a living body.
Some of the obstacles standing between humans and cryosleep are:
1)Cell Biology: Cells consist mostly of water and when water freezes, it expands. Expansion damages cells, irreversibly. To prevent this, scientists have proposed draining the body’s blood and replacing it with anti-freeze. On freezing, the chemicals would clump together to form a glass-like substance which would theoretically save the cells from bursting. However, this method has only been applied on already deceased bodies. How this would work for living humans has not yet been tested.
2)Slowing the Metabolism: If the body is to be kept alive for an extended period of time in cryosleep, energy has to be conserved. To conserve energy, metabolism of the body has to be slowed down, akin to hibernation. This will result in the heart rate and the body temperature going down. Now, this poses two problems. The heart stopping completely in the process and brain death. While cardiac arrest is something that can be dealt with with immediate action, brain death is permanent.
3) The Human microbiome: The human body is abode to thousands of colonies of micro-organisms. These colonies are essential for our health. Microbes living on and inside our body help in metabolizing nutrients, serve as a protective barrier against infections, produce vitamins and maintain the immune system among other things. Preserving these micro-organisms and then re-introducing them into the body on revival is also something that needs to be taken into account.
Bringing Cryosleep to Reality
Space Works is currently collaborating with NASA to develop a Torpor Inducing Transfer Habitat which will be used to transfer crews from the Earth to Mars. The principle behind these habitats is of Therapeutic Hypothermia(TH) where the body’s temperature is lowered by 5 to 10 degrees Fahrenheit resulting in metabolic rates declining significantly and the body entering an unconscious state. This method overcomes the problem of cell destruction due to cryogenic freezing mentioned earlier. Although this is still in the early stages of development, it is a promising step forward in sustaining the human body for, at least, the journey between planets in the solar system.
Here are some interesting results related to TH and torpor:
- TH is known to be an effective treatment for traumatic injuries.
- Human patients have been placed in the torpor state under TH protocols for up to 14 days and repeated induction of torpor has resulted in no negative effects.
- Studies on animals have shown reduced effects of radiation and cancerous tumor growth under the torpor state.
- Nutrition to human patients under torpor can be provided for around 1 year through an all-liquid solution.
You can look up more information on this on the official NASA website.
What to Expect in the Future
So, in conclusion, the development of cryosleep is not just beneficial for interstellar travels but it also has applications in medicine. If brought into reality, cryosleep could potentially be a game changer in all fields of science. From terminally ill patients to the journey to Mars, this one overlooked research area could change life as we know it.
The future that we’ve looked forward to in science-fiction movies and novels might just be fiction no more!