In modern-day spaceflight, most astronauts with long hair simply bundle up their hair to keep things in order in zero-g, or to ensure easy helmet operation during spacewalks. However, fast forward a few centuries to when entire human societies might live their lives without setting foot on a planet, and many things will have changed. Among larger things like culture and technology, hairstyles will probably also evolve. If long hair is still in fashion or if metalheads still exist, they may very well develop countless unique hairstyles that both look good and have zero-g/spacesuits in mind. What existing hairstyles might be extrapolated for use by these kinds of people? Ponytails and buns seem like obvious options, but what are some other elaborate styles that are both microgravity-compatible and spacesuit-safe?
On the other hand, could spacesuits be designed around long hair, rather than the other way around? Would it be practical to have, say, a helmet seal specifically made to be loose-hair-proof?