"Sleeping here in space is harder than on a bed because the sleep position here is the same position throughout the day. You don't ever get that sense of gratifying relaxation here that you do on Earth after a long day at work. Yes, there are humming noises on station that affect my sleep, so I wear ear plugs."
This is a response to the question, What's it like to sleep in 0G? It must be great for the back. Does the humming of the machinery in the station affect your sleep at all?
"I am not a great sleeper. I don't think I have ever slept eight hours straight in the last 20 years. I wind up waking up a couple of times. My dreams are sometimes space dreams and sometimes Earth dreams. And they are crazy."
This is a response to the question, Can you describe your sleep cycle over the last 300 days in space? Always a solid 8 hours? Did you ever get strangely tired or have you consistently felt well rested? Bonus Question: When sleeping, is your dream world mostly in zero-G?