NASA and ESA to study how artificial gravity can keep astronauts healthy

Scientists can alter the intensity of centrifugal force and decide to turn around a person's head or chest, but it's unclear exactly what will work. This is partly what the experience serves: they will better understand what gravitational effects would be needed to prevent the muscles from weakening it.

Whatever the conclusions, you will probably not see 2001habitat rotation styles at all times. You are likely to see something resulting from studies like this, however. If humanity must undertake trips to Mars or send more than a handful of people into orbit for long periods, it will probably want some sort of simulated gravity to maintain the fitness of future astronauts.