From outside, it looks like suspended animation, but what it is is frozen time. The spaceship works by feeding off the time inside it, so when, a few hundred years from now, the spaceship reaches its destination, not only will the crew be just as young, they won’t have lived at all.
The technology was developed by a couple of scientists from this club which got its subsidy from an eccentric billionaire. They started out to modify basic time travel algorithms to introduce movement, but for the contents to move, the entire machine needed to move. Whether it’s a bug or a feature depends on the spin you put on it.
For example, the first time machine resulted from a failed experiment to use friction in the fifth cardinal direction to heat coffee.