Oy indeed! Congratulations on seeing one science fiction-like movie (Mars was accurate. The catch-in-space happy-ending was sci-fi fantasy. Hollywood!).  It is not that resources are nil, it is the need for a lot of energy to deal with the limitations of a hostile environment as a visitor.   The other solution is a ship that is large enough to allow growing food, and recycling food and water to allow extended travel.  That looks like the solution for even shorter trips, like to Mars.  No stasis technology exists (nor for that matter, for a 500 year life-span).  As for limiting new people, what do you imagine would be the answer to managing a population that grows to  10, 15, 20 billion?  My final answer?  I did say not all possible futures written about were pleasant.  I don't like that answer, but it is one found in the literature. There are worse ones.  If this upsets you, consider how to avoid 20 billion people, or how to resource for that many without extreme environmental damage.