In July of 2005 a baby girl named Laina Beasley was born to a family in California. Her birth was remarkable only in that she had been conceived 13 years earlier, and then frozen to -235°C.
Earlier in 2005 Dr Mark Roth at the Fred Hutchinson Cancer Research Center here in Seattle induced suspended animation in mice for six hours by introducing them to an atmosphere containing 60 ppm hydrogen sulfide combined with external cooling. There's a really thought-provoking TED Talk about his work here:
http://www.ted.com/talks/mark_roth_suspended_animation.html
Human ova can remain fertile when frozen for more than a year, and human sperm can remain fertile when frozen for more than 12 years. In 2008 Hiroshi Suzuki successfully transplanted a previously frozen ova of a Labrador Retriever into another in order to preserve the genetic material of guide dogs, which are otherwise sterilized before they reach sexual maturity.
Artemia salina, the brine shrimp sold as Sea Monkeys, are able to survive for years in cryptobiosis, during which time they can survive extremes of temperature ranging from −190°C to 105°C for short periods of time. All this without human intervention, other than the school children providing the 105°C environments, with or without adult supervision. In an environment with no humidity and no oxygen they can remain in stasis for up to two years; in a more benign environment they seem to be able to survive indefinitely, like plant seeds.
So. This is where the science of suspended animation stands right now. Mark Roth disclaimers at the beginning of his talk that he isn't interested in using his techniques to extend the range of human space exploration. I happen to be.
But right now, it looks like about an additional 20 years is the most we can do. I'm actually guardedly optimistic that we are making such rapid advances in this field that we may see this number expand to a century or more, in which case all of the stars on my previous list may be within the reach of human colonists.
This would afford us gains in the distance a vessel could travel, but it would still need to be large enough to sustain an ongoing non-hibernating population of all of the colonists, human and otherwise. Because if the colonists reached their destination star and there was NOT a suitable candidate world for colonization, the vessel which brought them would need to sustain them, and their descendants, possibly forever.
But right now, with the suspended animation technology we currently possess we could extend the the reach of a single generation to Barnard's Star. Only. And Barnard's Star, frankly, isn't that interesting of a candidate.
So, Alpha Centauri it is, for now. In the next few posts we'll look more closely at our nearest stellar neighbor, what we might expect to find there, what the trip there might entail, and how we might make that a future home for some of our descendants.
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