Let's assume that Captain Bob Tiberius Kirk has been injured in a space battle. The universe does not have FTL travel, and the nearest hospital where Bob can be treated is 5 years of space voyage away. If he is not treated within one week, he dies.

I need a way to preserve Bob. Hard SF, so no stasis chambers and no magic stuff. It is not possible to treat Bob on the ship.

So...what should I use? Wouldn't throwing Bob into a vat of liquid nitrogen damage the body? Should he be frozen quickly or slowly? Should he be frozen at all (Cryonics is of course a good idea, but it is interesting to hear about other methods of conserving living beings)?

What is the best method to preserve a human being for a long time, with minimal damage to the body or unhealthy effects?

  • $\begingroup$ Why does Captain Kirk's ship not have any medical facilities? If there isn't a sick bay and some medical staff, what are the chances of it having a full cryonics suite? $\endgroup$ Commented Sep 12, 2015 at 19:57
  • $\begingroup$ Carbonite! Just as what happened to Han Solo. $\endgroup$ Commented Sep 12, 2015 at 20:00
  • $\begingroup$ We really need more information on what technology is available. What resources does this ship have? $\endgroup$
    – Tim B
    Commented Sep 12, 2015 at 20:28
  • $\begingroup$ Like it or not you must drain off the blood from Bob and substitute with saline solution and make sure it is around 10℃, thereafter introduce special chemical to reduce the metabolism rate of cells. Bob will be neither dead nor alive, upon arrival at nearest hospice treat the wound replace saline solution with blood and resuscitate Bob.🚑 $\endgroup$
    – user6760
    Commented Sep 13, 2015 at 6:54
  • $\begingroup$ Since all of the answers so far are aimed at essentially freezing the injured man until he can be treated, they all share the same "problem". If you have medical resources capable of safely performing the freezing process, surely they're capable of treating the injuries? With advances in expert systems and robotics, an autodoc will probably take up less space than a cryopod. That has the advantage that the Captain can get back to work once healed rather than sleeping the rest of the voyage. $\endgroup$
    – Steve Bird
    Commented Sep 13, 2015 at 9:47

3 Answers 3


Freezing a dying person can definitely help: as the saying goes, "they're not dead until they're warm and dead". The problem is that this causes serious tissue damage (in the present at least).

If you just throw Bob into a vat of liquid nitrogen, water will freeze inside his cells and cause them to lyse. So you'll have to be a bit more careful. If he's frozen slowly, the water will leave the cells through osmosis as the ice forms, so you won't have that problem. However, this means you end up with a lot of ice in the space between cells. As this ice expands it will push the cells apart and cause damage to the structure of the tissue, and when the cells thaw they will have lost a lot of water. Also, most chemicals dissolved in the water will not be incorporated into the ice, so the concentration will increase as the amount of liquid water goes down. Not optimal.

A small number of animals can survive freezing by replacing some of the water in their body with cryoprotectant (antifreeze) chemicals: waterbears use trehalose, wood frogs use urea and glucose. If you fill Bob's body with cryoprotectants the water will vitrify instead of freezing as it gets colder, avoiding most of these problems. The difficulty now is that most cryoprotectants either don't go through cell membranes, or are toxic in high concentrations.

New cryoprotectants are always being developed, so it's not much of a stretch to assume we've found something less toxic by the time we're fighting full-on space battles. Bob's comrades could fill his bloodstream with our fictional new preservative, then freeze him very quickly in a tank of liquid nitrogen. The water in his body would go into a glassy state (hopefully) without causing further damage. Then when they got back to the hospital he could be revived and treated for his injuries. This probably wouldn't be very pleasant for Bob, since it would effectively kill him for a time, but at least he would get better in the end.


You will need to:

1- Slow down the metabolism rate. Breathing rate should be decreased to 1 breath per minute. Heartbeat needs to be reduced to 3 heartbeats per minute. Energy consumption by the body needs to be minimized to no more than 5% of the normal energy consumption of the body (wake state).

2- A state of deep-sleep like condition needs to be implemented on the brain. The brain needs to stay function (so no freezing or stuff) but in a state between sleep and unconsciousness. It is important to not let the brain slip into coma and have the brain wake fully for 30 minutes or so, every week.

3- Tubes need to be installed in the kidneys and digestive tract.

4- A slow, but steady input of glucose and all vital food ingredients needs to be inserted directly into the patient's bloodstream.

5- All body muscles need to be kept active by artificially generated motor signals. If this is not done, the muscles would gradually get weaken and thin out.

Upon reaching the medical facility the patient would have aged only by around 6 months, biologically, despite passing 5 years.

I just don't understand ONE thing though. This dude went for a war where 5 years were wasted in reaching the battlefield while 5 more will be wasted when he returns to battlefield again after recovery. The poor fool sounds more like a space tourist to me, than a commander.


You might be interested in this article: http://www.shfwire.com/hibernating-squirrels-secrets-could-solve-medical-mysteries/ You could give the Captain a drug that puts him into deep hibernation, like arctic ground squirrels go into. Then he can be chilled to at (or a bit below) freezing. This will prevent brain damage. Medically-induced comas are already used, but one would hope that in the future drugs can be found that will reversibly slow down metabolism and increase resilience of tissues to very cold conditions.


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