How do astronauts in space go to the bathroom and take care of their personal hygiene?
Astronauts brush their teeth just like they do on Earth. There is no shower on the Shuttle, so astronauts must make do with sponge baths until they return home. Each Space Shuttle has a toilet that can be used by both men and women. Designed to be as much as possible like those on Earth, the units use flowing air instead of water to move waste through the system. Solid wastes are compressed and stored onboard, and then removed after landing. Wastewater is vented to space, although future systems may recycle it. The air is filtered to remove odor and bacteria and then returned to the cabin.

See Waste Collection System for more about the orbiter's toilet.

Is there a danger of dehydration in space?
The humidity here is at about 20 percent onboard the shuttle, so we do notice that things dry out rather quickly, including us, and we try to drink more water than we normally do on the ground. (Answered by STS-80 mission specialist Tom Jones.)

Does the crew all sleep at the same time, or does someone have to stay awake to monitor systems?
During a single-shift flight, we all sleep at the same time. We have a group of people in Mission Control who watch over us, and they have ways of waking us up. They can set off an alarm up here in the shuttle that will certainly get us out of the rack and get us looking at what they want us to look at. So we do all sleep at the same time but we're being watched over very carefully. (Answered by STS-80 commander Ken Cockrell.)

Is the crew still asleep at the time of the wake up call?
Some crew members like to set their alarms a few minutes early so that they are alert by wake-up. It's a nice time to be awake since the ground is not going to call them unless there's an emergency. For those still sleeping at wake-up, the wake-up music usually does a pretty good job of clearing the cobwebs.

Does weightlessness affect the crew's dreams?
I believe that weightlessness does affect the types of dreams I have experienced. I tried to make a point of remembering what I was dreaming about last night and I do remember some images of not walking but floating, so I would have to say that the impression on my body and on my memory of floating in space that I've done up to this point does re-manifest itself through my dreams. I have not had, that I can recall, the experience on the ground of dreaming of being weightless, although ever since I was a young boy I dreamed that I could fly. I know that's a fairly common experience, but perhaps that was anticipation of what I'm doing now, and perhaps now when I dream of flying when I'm on Earth, maybe that's reaching back into these memories. (Answered by STS-82 mission specialist, spacewalker Greg Harbaugh.)