 There's no pressure. You're in a vacuum. There's no air. But you also need things like food and water, breathing air to survive. So what do you do about that, and what are the effects on the body? And we have a pretty good understanding of that through our space shuttle flights and our experience on the space station, having people living there. So we try to inform the viewer of what that's like, but at the same time extrapolate it to, what happens if we want to go further into the universe, explore our solar system and beyond?