The methods vary radically from case to case. Cryogenic trickery is apparently good for a couple of centuries: Khan survived, but many of his groupies died, and the loss rate in "The Thaw" was high as well. Transporter stasis is normally only good for hours or days at most, as in "Counterpoint", and the 50% losses accompanying Scotty's "Relics" trick don't evoke confidence in the method...
Apart from these, though, there seems to exist a third stasis method that seems to literally slow down or stop time. The Slaver system from TAS was good for a billion years! Something similar seems to be in use on Starfleet and Cardassian morgues, and perhaps this is what protected our Voyager heroes in "One".
One wonders about the cryostasis of "The Neutral Zone". The subjects were dead already before being frozen. Perhaps this helps with preservation - the crudity of the method would allow for robust storage, and the burden would be switched to the reviving party. I wonder if Crusher could have so efficiently revived dead corpses stored in any other method?
There's also always the option of storing abstract consciousness: Trek is full of seemingly eternal and immortal creatures of this sort, sometimes being held in passive storage such as Sargon's sphere folks in "Return to Tomorrow", sometimes kept in seemingly active captivity such as the God of ST5:TFF. I wonder if, say, Data, or Ira Graves inside Data, would really have been immortal if they decided to park their android bodies in a safe vault and power down. That sort of stasis might be good for billions of years, without requiring the major physical breakthroughs of the time-stopping Slaver field.
Timo Saloniemi
