In a not-so-distant future, around 2300, mankind finally find a way to keep the body intact over hundred of years, allowing a limited number of humans to travel over hundreds of years in order to join close galaxies (no there is not "warp" or faster travel technology, so I expect people to live, reproduce, but also sleep a long time in the spacecraft).
I wand to find ways of keeping the human body and mind in stasis. Cryogenic sleep is a well-known way of allowing characters to do deep-space exploration, but I would like to avoid it, first because I m looking for something else, and also because I consider it lacks a good scientific explanation. One alternative which is being explored now is an hibernation state which would keep the body with essential water, but to me it is very similar so I am looking for something else.
So, would you have alternatives?