Ask the Crew: STS-111

From: David E. Robinson, Indianapolis, Ind., Age: 29
To: Commander Ken Cockrell

Question: On the front of your launch and entry suits there is a white strap. For what purpose is that white strap used?

Cockrell: The white strap, David, is called a hold-down strap or a pull-down strap. It actually connects to the front torso of the suit and the neck ring of the suit. Normally, it serves no purpose, but when we're seated in our seats on the space shuttle, we cinch that strap down so it sort of pulls the neck ring down toward the torso. And it's useful in case the suit ever has to inflate, if we have a loss of cabin pressure.

When the suit inflates, the neck ring tends to float up, and if you didn't have a white strap there, the neck ring would probably be up somewhere around your eyes. So with the white strap, it keeps it down around your chin and enables you to still see out the visor of the suit. So it sort of keeps the suit under control if it ever were to pressurize.

From: Christine, Pass Christian, Miss., Age: 7
To: Commander Ken Cockrell

Question: Is the food in space as good as the food on Earth?

Cockrell: That's a very good question, Christine. The food in space is pretty good. They've greatly increased the variety that we have to choose from. And now that we have a partnership with Russia and many other nations as well, we have, not only the American space food, but also the Russian. And this time, we have coffee from France and from Costa Rica as well. And so we have a very good selection.

I think everybody still has some favorite foods that they miss on Earth. We can't get fresh pizza, for example, and it's very rare that you get ice cream onboard, but, in general, we eat pretty well on orbit.

From: Paula Clark, Issaquah, Wash., Age: 48
To: Commander Ken Cockrell

Question: Hi, I really enjoy watching you on NASA TV. How did you decide the design of your crew patch for STS-111? Does each of the crewmembers get to put ideas into the design?

Cockrell: That is certainly true. We came up with half a dozen designs that were made by a friend of ours that's a professional graphic design artist out on the West Coast, and he sent us a number of designs, probably eight or nine. We zeroed in on one of the ones that he had, and then put a whole bunch of changes in it -- based on the input from each of the crewmembers -- and finally came up with the patch that we have now, which we're really happy with.

From: Paul, Encino, Calif., Age: 38
To: Commander Ken Cockrell

Question: Do your ears pop like when you are in an airplane?

Cockrell: Paul, the good answer is that: no, they don't, in general, on the space shuttle. Ears pop in an airplane as a result of changing cabin pressure, and in an airplane the cabin is maintained in a comfortable level, as they tell you in their preflight briefing. However, it does change as the airplane climbs. The cabin pressurization system attempts to keep it close to sea level, but it actually does climb a little bit inside the cabin.

In the space shuttle, we keep our cabin altitude the same as sea level all the time, except for minor changes when we're equalizing pressure with the space station or with another traveling vehicle that we're docked with. And occasionally, we change the pressure inside to make it easier for the EVA guys to transition from sea level pressure to the low pressure that's in the suits.

But on this flight, for example, we're keeping the pressure of Endeavour the same all the time from liftoff to landing, and so we don't have any earpopping. In some ways, space travel is more comfortable than travel in an airplane, in that regard.

From: Chris Woodward, Reading, Pa., Age: 46
To: Commander Ken Cockrell

Question: As you are aware, an annular solar eclipse will begin ~2100 UTC on Monday, June 10 and end ~2:35 UTC on June 11. Will you be able to see the shadow of the Moon cross the Earth?

Cockrell: We have been told about this eclipse, Chris, and we're looking forward to attempting to photograph that shadow. We believe it's going to be a complete eclipse in the Southern Hemisphere and partial in parts of the Northern Hemisphere, so we hope to be able to get some good pictures of the shadow of the Moon going across the Earth. We'll be trying to do that tomorrow.

From: Susan Jones, St. Paul, Minn., Age: 44
To: Commander Ken Cockrell

Question: Hello, we have two questions about the orbit of the shuttle. When docked with the space station, what is the altitude? What is the length (distance) of each orbit? Thank you very much.

Cockrell: The altitude: Yesterday, we did a little reboost maneuver. We raised the altitude about 1 mile. We are going to do a couple more of maneuvers during the flight to keep the space station up at the altitude that we like it at. It is at about 211 nautical miles above the Earth, and a nautical mile is 6,080 feet. So it is a little bigger than a statute mile. So in statute miles, we are about 250 miles above the Earth. What that means for the length of the orbit is it is not a whole lot further around the Earth at this altitude than it is at the surface of the Earth. So about 25,000 miles around the Earth, and it takes us about 90 minutes to make that orbit.

From: Kannaiyan, Ilford, Essex, U.K., Age: 27
To: Commander Ken Cockrell

Question: How do you differentiate between a bottom and a top when you are in space? Is it just above your head and below your head?

Cockrell: That is basically true. You can set your own coordinate system by just deciding that when your head is pointed in a certain direction and that is up for you. Sometimes that gets a little confusing though when you enter a module, in the space station for example, and the ceiling is in a different location from the direction your head is pointed. So it can be a little surprising when you set your own coordinate system and you think your up is up and then you look around you and you see that another module or the other people in that module have chosen a different coordinate system. So it provides a little interest to the up and down question in space. But basically, as far your inner ear and balance organs are concerned, any up you choose is a good up.

From: Rainer Christiansen, Leck, Germany, Age: 27
To: Commander Ken Cockrell

Question: Hi, as a glider pilot, I want to know if you can hear the wind noise during the landing approach in the lower parts of the atmosphere. I know you are protected by your headsets and helmets, but due to your speed and higher density in the lower part of your approach, it should be pretty loud inside the cockpit. Thanks and good luck!

Cockrell: Well Rainer, the answer is yes. You can certainly hear the wind noise. It is quite an interesting thing. I am also a glider pilot myself. I haven't flown high-aspect-ratio or high-lifted-drag-ratio gliders in a long time, but I know how important the sound of the wind is. It has the same feeling to you in the shuttle. We spend several days, 12 days in this case, orbiting around the Earth with no wind noise. The only sound we hear are the noises created by the equipment inside the cockpit. So at about mach 5, descending through about 90,000 or 85,000 feet above the surface, the wind noise begins. And, it is almost a surprise because you haven't heard it in so long and it sounds really good to your ears. It actually increases in volume until around mach 1, I suppose. And from then on down to landing, it's a relatively constant sound, and one you get used to just as you would from flying a constant speed in a glider. Very good question, and it is a noise I enjoy hearing during the last part of the entry.

From: Laurie Koszuta, Niceville, Fla.
To: Pilot Paul Lockhart

Question: While in space, what time do you synchronize your watches with (if you use watches)? That is, what time zone do you go by so that you know when to sleep, etc.?

Lockhart: The answer to that, Laurie, is: On the shuttle we use mission elapsed time. This is kept by the computers as soon as launch is initiated. And once we are on orbit, we have our own watches that we then set to the computer�s time so that we each are keeping track of our duties according to the mission elapsed time. When we docked to the station, they used Greenwich Mean Time, GMT, and so whenever we did tasks that went back and forth between the station and shuttle, sometimes we had to do a little math in our head to make sure the times were proper. For example: when we got prepared to do spacewalks and so forth. So anyway, on the shuttle we use mission elapsed time, and on the station, they use Greenwich Mean Time.

From: Steve Lehr, Bellevue, Neb., Age: 46
To: Pilot Paul Lockhart

Question: When maneuvering close to the space station, at what scale do orbital mechanics effects become significant? If, for example, you're a few feet behind the ISS, does thrusting forward (i.e. along your velocity vector) bring you closer, or does it, instead, raise your orbit and actually separate you farther?

Lockhart: Steve, the basic answer for that is that there's orbital mechanics effects at all times, but we start flying manually the vehicle inside of about 1,500 feet when approaching the space station or any other object in space that we are docking the shuttle to. The way that we are able to overcome a lot of the orbital mechanical effects are to keep out inputs to the orbiter very small so that we are able to compensate for any of the orbital mechanics effects. This allows us to basically maintain a small corridor on our approach path to the target so that we are able to fly basically straight lines. (Second part) Yes, if we stayed out of the loop and didn�t try to correct for any of the orbital mechanics effects, then those effects would take over, and sometimes the vehicles, when we try to come together, would actually start separating. However, we are able to stay in the loop and make those corrections and dock the vehicles very precisely within a few inches.