NASA Plans a Manned Flyby of Mars, Mission to Europa

[Alleged_Alec]

Ouch. 19 months in space. I really hope they'll have some form of artificial gravity on those ships. I don't want to know what would happen to your bones if they don't have that...

Astronauts on the ISS do regular exercise including running on treadmills (held down by straps so they can actually run) to keep up their muscle tone.

As far as I know, we're still a little way off artificial gravity.

Not really. As long as you have a rotating crew section, you have artificial gravity. You don't need science-fiction like stuff. Just place some high ISP, low impulse engines on the ship in a way which would impart rotation when fired, and after making the burn for Mars, fire those engines until you have the proper amount of simulated gravity.

I've heard that idea proposed before but I thought it wasn't especially practical. Unless the ship is very very large, you end up with noticeably different "gravity" between your head and your feet, which means all the blood gets pulled away from your brain. Which isn't ideal.

Strapping astronauts to a treadmill is still probably a more reliable solution to the problem.

True. If you want to make a 1 G environment out of a normal crew capsule, it would fuck with the blood flow significantly. However, if you go for something less than that, on a larger ship, there would indeed be a difference in gravity, but not one serious enough to cause problems, while still keeping your bone densities up a bit. Treadmills are nice for muscles, but they don't really help all that much in keeping the bones as they should be.