text: is suspended animation at cryogenic temperatures a good future strategy for manned space exploration? speculative fiction writers have long envisioned the potential of freezing people for long, dangerous space journeys to other worlds (both within our solar system and beyond).  while the technology does not currently exist to freeze and thaw people properly, does the potential for such technology warrant a renewed look by private industry and by government researchers?  note naturally that nature provides for some animals to survive in subzero temperatures by freezing solid and thawing (including some frog species).  note also that the damage done is not from "cells exploding" as sometimes mischaracterized by opponents of cryonics, as vitrificiation and precludes this. you've got a couple of questions in there - not that i mind, they're good questions. :>  1. "...does the potential for such technology warrant a renewed look by private industry and by government researchers?"  even without any bearing on manned space travel, absolutely. think of the applications for medicine, to name a field... if we can put people into safe suspension for even 24 hours, imagine how much more effective and safer surgery would be.   2. now, as for manned space exploration... "it depends" kind of sums up the options.   2a. what's the safety factor?   i'm leery of cryogenics, for the reason that i'm not aware of any large-brained animal that can fully recover after having been frozen. yes, i know, people have been revived after thirty minutes under the ice..  but i mean, frozen *solid.*  i'm no expert on this subject. please bring on citations to the contrary, but freezing one's brain has to be an order of magnitude more difficult than freezing the rest of one's body. i don't want to come out of the freezer unable to remember my name...  2b. what's the scope?   almost by definition we're talking about interstellar missions. the only way i can imagine that we'd seriously push for some kind of human estivation in interplanetary travel, is if there was some tremendous urgency in establishing bases in the outer solar system...  for example, solar-system-wide, international competition, first one there gets the helium 3 and a great view down the gravity well. that imperative would over-ride the hazards of daring such exceedingly long trips (saturn, anyone?) with chemical propulsion.   without such a driver, we'll just have to wait until nuclear rocket propulsion or magsails come on-line.   by definition, an interstellar voyage will be a long one- and an irrevocable one as well.  2c. what's the mission? colonization or exploration?   it was a common experience for immigrants to the united states, until about 50 years ago, to regard their trip here as an essentially one-way voyage.   future emigrants from our solar system would have to have much the same attitude, regardless of travel velocity; therefore, travel velocity would play second fiddle, i think, to the overall object of getting a colony-sized vehicle up to *any* fraction of light. if so, then suspended animation would be hugely important, as it would avoid the enormous difficulties of a generation ship.   i can grok a high-tau mission to a nearby star without hibernation - time dilation will shorten the trip considerably for the explorers.   that said... it's not unlike saying "giant squid calamari will be the absolute best seafood ever" - one first must have caught a giant squid! so the last requirement for my post will have to be:  2d. what's the engine technology?   voyaging at a high fraction of c would be great for a number of reasons, but, but, but. that's pretty advanced tech. and this too determines or influences a number of other decisions.