Ask the Crew: STS-108

From: Christine Wells, Manassas, Va., age: 11
To: Mission Specialist Dan Tani

Question: What is it like during liftoff? Thanks!

Tani: For me, it wasn't exactly what I expected. It being my first flight, I didn't have a lot to base it on. It feels pretty much like what you would imagine when you watch a launch and you see how powerful the SRBs are. The orbiter shakes a lot, it's hard to read the displays and gauges, although you are able to do that. The way I thought about it, it's kind of like what you would expect a train going a thousand miles an hour to feel like. There's a lot of shaking and acceleration, and you can feel that acceleration. Once the SRBs come off -- the Solid Rocket Boosters -- the ride gets a lot smoother, but towards the end of powered flight the g-forces build on your body considerably, up to about three g's, and then when the main engines shut down you immediately go from three g's to zero g's and you're floating in space.

From: Linda Pudwill, Detroit Lakes, Minn., age: 48
To: Commander Dom Gorie

Question: Since you have now visited both Mir and the ISS, what are the major comparisons and contrasts between the two?

Gorie: The differences are that the first time you see the International Space Station during the approach, you are overwhelmed by the beauty and the symmetry of this large space station, where the Mir was not quite so symmetrical. And also, when you're in the International Space Station, you're aware of the increase in size, and certainly, the condition of it is much better than Mir was. Mir, I can make an analogy to driving around in a motor home for 12 years -- it takes a little bit of abuse, it was quite crowded. It didn't have near the volume that the International Space Station does.

The similarities are: When you're going through multiple modules or segments in a space station, you always have this ability, when you come to an intersection, of going up, down, left or right, which is totally different from anything you been used to in the space shuttle, so that's probably similar. The Russian systems and modules look remarkably similar, although they're in much better condition now. Those are the major comparisons and contrasts I have. Linda, thanks for your question.

From: Andrew Hewett, Colorado Springs, Colo., age: 8
To: Mission Specialist Dan Tani

Question: What does space ice cream taste like?

Tani: Andrew, we usually don't carry ice cream on the shuttle. That would require a freezer and something to keep it cold. There is some commercially available stuff they call "astronaut ice cream" and that's just freeze-dried, I guess. We don't carry that either, so we don't get to eat either the fresh or the freeze-dried ice cream on most flights, but I'm sure it would taste just as delicious as it does on the ground, because most food up here tastes really good after a hard day's work.

From: Ed Otto, Indianapolis, Ind., age: 45
To: Mission Specialist Dan Tani

Question: Do you feel the roll program initiate when the shuttle goes 'head-down' or is that feeling overridden by the 3G of thrust you are experiencing at the time?

Tani: Ed, the roll program happens right after the pad at eight or nine seconds after we lift off. At that time we're not under three g's -- it's generally just about a g-and-a-half or so of acceleration. We were talking about it last night, and I really did feel the roll program, and it kind of surprised me, or I was surprised how much I felt it. Some of the other folks did not and thought it was more a visual thing, but I thought that I really did feel the roll program. The three-g acceleration happens near the end of the burn, about eight minutes or seven and a half minutes into the flight when we're really pressed into our seats and you can really feel that three-g acceleration.

From: Terje M. Hougen, Pensacola, Fla., age: 35
To: Mission Specialist Dan Tani

Question: In most pictures of the astronauts, I have noticed that they wear two wristwatches. My question is: Why?

Tani: Actually, I'm wearing three things right now that look like wristwatches. We have three units of time up here, at least while we're docked with the space station. One is called Mission Elapsed Time -- MET -- and that starts at zero when the shuttle lifts off. Everything on the shuttle is referenced to Mission Elapsed Time.

We also have Greenwich Mean Time because that's the time that the space station works on. That's the standard Greenwich Mean Time that starts at zero on January 1 and counts up in days, minutes and seconds. The last time we have is Houston time, mainly because we want to know when our family is waking up and having dinner and going to sleep just so we can kind of keep in sync with them.

But the other thing that we wear that looks like a watch is actually an experiment that measures the light that we're seeing at the time. It records when we see light and when we see dark. They use that to look at different things -- the quality of our sleep and other factors. It records the light and dark cycles that we experience here in orbit.

From: Bruce W. Brown, Huntington Beach, Calif., age: 50
To: Mission Specialist Dan Tani

Question: How does seeing 10 or 11 orbital sunrises during every wake period affect your body clock, and how many of the eight hours during a sleep period do you actually sleep?

Tani: One of the surprises of a first-time flyer, for me one of the surprises that I had in orbit, is that my sense of time is completely off since -- he's right -- the Sun comes up and down, it's dark, it's light outside, and a lot of the time we don't even see the Sun. We're in the middeck or we're in the MPLM, so there are times through the day I have no idea if we've been working for two hours or eight hours, or if it's dinnertime or what.

So that relates to another question about time, that I always have to keep a watch on to kind of get a sense of what time of the day it is. In terms of this flight -- our particular flight -- we have been very lucky in that we haven't had to shift much of our sleep. We've been working pretty much the same hours as we would have in Houston, so we really haven't had to shift our body clocks that badly.

Our sleep period, we are reserved for eight hours of sleep period per night. We probably get around six or so, mainly because we're so busy and we spend a lot of our time that we have allocated for sleep either finishing up our work or having dinner or spending a couple of minutes talking about our day, so we get probably about six or seven of our hours of sleep. For me, at least, I sleep very well up here. It's very comfortable and before I know it, it's time to wake up.

From: Les Pruszynski, Palm Harbor, Fla., age: 32
To: Commander Dom Gorie

Question: When docked, who is in control of the orbit, the shuttle or the space station?

Gorie: Les, From the moment we make contact, we immediately go to free drift so nobody's in control for a short time, but for the majority of the mission the space station takes over attitude control except for when we do large maneuvers. When we have to turn 90 degrees or 180 degrees to do a water dump or a reboost, then the shuttle takes over and uses the reaction control jets to maneuver and hold attitude.

From: Fifth Grade Class/Thomas Lake Elem., Eagan, Minn.
To: Commander Dom Gorie

Question: We are watching NASA coverage in our classroom with much interest. Zero gravity and living conditions prompt the most questions. Here is ours. Could you tell us about the exercises you do on the space shuttle: types of exercise, equipment used and duration? Thank you!!

Gorie: For those fifth graders, what we have on the space shuttle is an ergometer, which is an exercise bicycle. It's got some special pedals with special shoes that clip in so that you don't float off when you're riding the bike, and it has a strap that we can put around our waist to hold us down as well. You can set the difficulty with a little knob to pretend you're either going uphill or downhill -- kind of a bike ride. We usually get scheduled every day to ride the bike for 30 to 45 minutes. I know, with our busy schedules we try to get that at least the second or third day in. Yesterday, I rode for 40 to 45 minutes and at the end of that drill I had ridden the bike halfway around the world.

From: Rick Hough, South Hamilton, Mass., age: 41
To: Mission Specialist Dan Tani

Question: What was the highlight of your space walk, and did you get any feeling of speed as you were hurtling around the Earth?

Tani: Rick, there are two highlights I had. The first was to get the blankets on those Beta Gimbal Assemblies. That was our primary task, and when we finally got both of those on I was really pleased that we had accomplished our primary mission of the space walk. The second was flying over Houston and being able to look down near the end of our space walk and seeing the entire city, seeing my neighborhood and knowing that all my loved ones are down there.

The sense of speed on the space walk was great. You can see the ground going by at 17,000 miles an hour and -- just like in the shuttle -- I'm really surprised how quickly we go from day to night. It happens over a 10- or 15-second period, and that really accentuates the sense of speed.