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STS-112 International Space Station
Question and Answer Board

William from Taipei
How do the doors on ISS work? I mean, the seal of the door of each module?
Yes, as a matter of fact there are. There are three seals between each of the doors of the space station. It's a material called (Vy-tahn?) and it makes sure we have structural integrity and also a very, very small leak rate when we berth the different modules together. And then also at each module there are hatches that can be closed, and they have the same triple-redundant safety seal as well.
Hywel from Great Britian
How is power stored on the ISS? What types of battery are used and how much power does the space craft need?
That's a very good question! They're nickel-hydrogen batteries and they're very powerful, and that's what stores the energy from the solar wings. The wings, of course, during the 45 minutes of each rotation that we're in sunlight, store power. And then we drain the power out of the batteries during the 45 minutes that we're behind the Earth, in the shade. So it's a constant charging and draining process that provides the power to the station.
Sauli from Helsinki
How well organized is life on the ISS?
Well, let's see. We try very hard to have a very structured day for the astronauts on orbit. I think the question was in reference to a time when Peggy Whitson had quite a bit of trouble finding a particular wrench or tool she was looking for, and just like any other home -- which the space station is -- or workshop, everything has its place and we try to keep everything in its place. But from time to time, things do get misplaced. In this particular case, the tool was found and we were able to continue on with the task. Now that becomes a little bit more complicated when we're doing an EVA, or spacewalk. And for those particular situations we have a broad array of tools -- there's generally more than one tool that will do the job -- and we also have bags of tools stored in particular places so that if they need a tool and don't have it, they can go get it.
Shane from Mitchell, Nebraska
How long do people live up in the space station and how do you get food up to the people?
Well, typically, we plan for four to six months. They of course go up and come back by either Russian craft or on the space shuttle, and we take them food and supplies in two different ways. One is on a Multi-Purpose Logistics Module that launches in the shuttle payload bay, and the other is from resupply ships sent aloft from Baikonur in Russia.
Andy from Gilford
I am in eighth grade and studying about space. When the shuttle launches, and "white stuff" comes off the side, is that some form of ice that is formed when they empty? Thank you, Andy
Oh, that's a neat question! Actually, the external tank is filled with very, very cold liquids -- hydrogen and oxygen, cryogenic liquids -- and there's ice that forms on the outside. So during the launch process you'll see there's a lot of shaking and rattling and rolling, and that ice comes loose. In the Launch Control Center, where I am very privileged to play a part there, there is a special part of the launch control that is specifically the Ice Team. They go out and they look over the vehicle. They're the last ones come off the pad, to make sure that we haven't had enough ice buildup to create a problem at launch. Great question!
Charl from Johannesburg
When will NASA be able to create artificial gravity in space or perhaps even on the ISS by means of rotation or other? Is it possible? How effective will it be? And is it economically? How important is this to NASA and when will this happen?
Well, that's a possibility. That's one of the ways it can be done. In fact, that's the only way we can do it now, as a function of centrifugal force, and there was actually a module at one point dedicated only to create an artificial gravity, if you will, on the station. It's not currently in the baseline, but there are experiments that will create that.
Stephanie from Tasmania
Are there any life forms out there in space?
Great question! And notice Tasmania. Look at all the places people are asking these questions. I love it! Well, we know absolutely, positively there is life in space. There are three people up on the space station right now. Beyond that, I don't have any conclusive evidence to say that there is, but my gut feeling is that surely with this vastness of the universe, there's bound to be life out there in unimaginable, interesting variations and I can't wait for us to find them.
Ashley from Sacramento
I always watch NASA TV when it is on. My question is will they be taken pictures of our moon being up 300 miles above earth? Pictures should be great?
As a matter of fact, there are several photograph-quality, very special places, and one is in the U.S. Lab module where there's a large -- call it a picture window -- for taking photographs. It mostly points down at Earth, or actually, all the time it points down at Earth, so we can take pictures of the Earth. But there are other places where you can take pictures of the moon and other astronomical readings as well, so yes, there is a lot of that type of science work being done on the station.
Terry from Reno, Nevada
How many people are normally in the space station during a mission, and how crowded are they?
Very good question. There are three people permanently on the station, the crew that rotates out periodically. When the shuttle goes up, it carries up to seven additional people so we can have as many as ten at a time when the shuttle is there. And when Russian ships come up, usually there are two people aboard, so there's either three, five or ten people on the station. Permanently manned at a level of three. Very good question.
Jeff from Newport Beach
Will the ISS act as a stepping stone to perhaps colonize the moon?
Great question -- and I sure hope so. One of the things that the station was designed for is to serve as a way station traveling to other places like to Mars or to the Moon, so I sure hope it gets used for that purpose.
David from San Diego
It seems inefficient to use rockets to send supplies up to the ISS. Can't you use Earth's centrifugal motion to defeat Earth's gravity?
Great question! Now, here we have a gentleman thinking outside the box. I read a science fiction novel once by Arthur C. Clarke, where he envisioned a ring like a hula hoop around the Earth at a geosynchronous orbit 22,500 miles up. So think of a basketball in the center, that would be the Earth, and a hula hoop outside it that man has built 22,500 miles up. The neat thing about that is that at that point, the place on the station and the place on the Earth as they went around would always be perfectly aligned. So you could, in theory, build an elevator shaft that would allow you to move supplies up and down from the station. Now today, that's beyond our capability. But if we can dream it we can do it. And I think if you'd asked someone a hundred years ago would we have an International Space Station, would we have a space shuttle, the answer they'd probably tell you is that you're crazy. And while the notion of using an elevator shaft to get supplies and people up to the station may sound far fetched today, it's not beyond the realm of possibility.
Heidi from Germany
Where can we find information about the inside of the ISS? How do astronauts sleep, wash, etc.? We have a space unit in our English lesson.
Well, let's see. Heidi, there are a number of places where you can go and get that information. One of the best ones is to go to NASA's Web site. There you can learn about how the astronauts live and the science that they're doing. Now, your specific question is about their personal space. On the space station, in the service module that's provided by our Russian partners, each astronaut has a living compartment about the size of a telephone booth. In there they have a radio, a place to sleep, and other personal effects, and we also have a shower that they can use. It's not like a traditional shower, it's more like crawling in a sleeping bag, and sealing it at either end and passing water through, so we don't get water all over the station. But each of the personal hygiene needs of the astronauts has a unique solution for the challenges of space, and you can see more about that on NASA's Web sites.
Siegfried from Zuerich
Do you have a heating in the ISS and where do you get the energy for this? Are the astronauts overalls heated or not like in 1964 at the Moon exploring program from Europe. (2 girls astronauts, 6 boys). Why do you have always white astronautic clothes and in the ISS blue ones.
Heating is an interesting challenge on the station. We have systems that take heat out of the station and dump it overboard, and we also have systems that add heat to the station, and we try to maintain a balance. As you can imagine, as we go around the Earth every 90 minutes, we go from the intense heat of the sun to the intense cold in the shade of outer space, the shade of the Earth on the back side of the Earth, and we have to balance the either heat rejection or adding heat. The heat rejection is through heat exchangers, that's how we add cool inside the station, and then the station is heated through pads that are fixed to the shell of the station, that are very similar to the heating pad that you use at home. It runs off the electricity from batteries and it tries to keep the station at a very comfortable temperature at all times.
Emilio from Lugo, Spain
How much time can be the ISS in space? 10-15 years...
Hola to Emilio! We're designed for 10-15 years, but I believe, having been involved with the development of the station, that its actual working life will be much longer than that. I think more on the order of 25 to 30 years. But the certified design is 10-15 years.
Steven from Frankenmuth, Michigan
Is NASA worried about Russia not having enough money to build rockets to supply the space station in the next couple of years?
It wouldn't be appropriate for me to make an official statement for NASA but I can give you a personal opinion. And that is, everybody's hurting for money these days. Every dollar that is contributed by every one of the international partners is very precious. Our Russian friends are struggling with their budget just as we in the U.S. are struggling with ours, and I sure hope that there'll be enough money among all the partners to see the station through to its natural conclusion, and that is to get all the science out of it that we possibly can.
Ted from Chapel Hill
What is the composition and pressure of the atmosphere inside the space station?
Well the pressure is just the same as here on the ground, 14.7 psi. And the composition is just the same as air. We have, inside the air revitalization systems, what they call a major constituent analyzer that looks at the composition of the air, and then we have the capability to adjust it to make sure it stays just as same as it is here on the ground. Nitrogen, oxygen and all the other stuff.
Robert from Dallas
What is the altitude of the space station and the speed?
Altitude is about 200 nautical miles 240 perhaps and the speed is 17,500 miles per hour.
Nick from North Attleboro, Massachusetts
How many more shuttle missions are going to be launched in an effort to make more renovations for the ISS?
Okay, we're now about halfway through. We're about 20 missions into a total of 42 or 43 missions to complete the Station, and that will change just a little bit as we add and subtract things to different mission plans, but it's about 40 missions. Now that's total between the Russians and the Americans who have the launching services. But it's about 40 to get the Station complete.
Javier Martin from Hampton, Virginia
Are there plans to transport animals to the ISS?
I think there are. I'm more of an engineer than a scientist, so I can't tell you what all the plans are for the science that's going to be done on the station. But we have a long track record where NASA supports science that involves animals, all the way back to the Apollo days. And in Spacelab they flew a number of missions that had animals, and space station has already flown some that I think had very small animals. I don't think we'll ever see anything really, big but perhaps monkeys and mice and things like that for some of the experiments.
Alli from Cocoa Beach
How do the astronauts train to build the space station?
They train in a number of different ways, and that is a really good question. Part of their training, they do here at your home in Cocoa Beach, out at the Kennedy Space Center. They actually come out where the hardware is, and anything they have to do on orbit, they practice, flight hardware to flight hardware here on the ground. In addition to that, there's a large tank in Houston called the WET F Facility where they put on space suits and can go and practice all of their spacewalks and all of their operations that need to be done there. So it's a very fine timeline, very practiced, as to what the astronauts are going to do and they have a number of different locations where they do that.
Paul from Consett, England
Has the Moon been chosen as the next stop in building, after the station is finished, or will the station be added-on continually?
Gosh, that's a great question, and I hope that the Moon will be the next location where we build a station or a moon base. It's a logical step, it's a logical leap from there to Mars, and it's logical also to use the International Space Station as a way station on the way to a lunar base. So I don't think that there's a commitment yet, and that's what's required from the world community or the U.S. community, to do that. But I sure hope there will be.
NASA's John F. Kennedy Space Center