(all directional references are in relationship to the floor of the vehicles mentioned)
If you’ve ever seen video of sleeping astronauts aboard the space shuttle, they are usually in “vertical” sleeping bags.
How difficult would it be for them to sleep “horizontally”?
What about tossing and turning? Is there any danger of astronauts injuring themselvves by doing so?
Do they sleep in the same way aboard the ISS?
There would be no difference at all.
I suspect that it’s just easier to tether their sleeping bags to a surface that is normally used as a wall when the shuttle is under gravitational acceleration. Better to have attachment points on the wall then on the floor when you’re doing maintenance on a shuttle that is sitting on the ground. Less stuff to trip over.
I don’t have a definite answer, but I suspect that they’re tucked in pretty tight.
Well, obviously, there is no preferred frame of reference in space, hence, no “vertical” or “horizontal.” It doesn’t make any difference to the person sleeping.
How difficult would it be to change? There’s nothing stopping an astronaut from putting his bag at 90 degrees to the others, assuming there are connection points. But obviously it’s a more efficient use of space for them to line up parallel to one another.
The astronauts report not tossing or turning as much in space as they do on earth, since such motion is usually done to shift weight onto a different part of the body. Of course, in space there is no weight pressing against a mattress. The restraint bags effectively keep them from swinging an arm out a smacking the wall of the compartment.
In the ISS there’s enough room for each crew member to have an private compartment that’s sort of a combination bedroom/office, with a sliding door that can be closed. They have sleep restraints that are similar to those in the Shuttle, IIRC.
In some of the Apollo film footage, you can see that the astronauts slept (at least part of the time) where ever they happened to be at the moment. IIRC, the sleeping area for one of the astronauts in the capsule was under the acceleration couch.