Dr. Susan Fehres chat 1/21/97 Hello, This is Susan Fehres, Dr. of Mechanical Engineering Extraordinaire. IUm doing a project on NASA. I'm in fifth grade and am using this chat as part of my project. Here are a few questions. What does math have to do with science? Math is the way you figure out relationships between things, like energy input to temperature rise, weight of spacecraft (or car) and efficiency to the amount of fuel you need. We need to quantify physical reality in order to accomplish physical goals - like transporting food to people in need, how many vaccines to ship to Africa, whether or not a drug affects an illness, how to send a ship to Mars... What is your favorite part of the day? Morning, after i drop my daughter at our day care center, walk, here to my office, and i am reading my mail, drinking my coffee, and looking at my planner to see what i wrote myself in for doing today. such a peaceful time of day. i havent fallen behind yet, and could do anything with the day. ********** Why do you have to ship vaccines to Africa? That's not NASA - what i meant was, for us human beings to accomplish most of our goals, we use math to figure out how much of anything we need to do- NASA goals include space exploration, all aspects. Other significant human goals and accompishements also require math, in their scientific aspects . To decide to ship vaccines to Africa is a political decision. To decide to go to the moon, or have a Space Staion, or go to Mars, is also a political decision. But - To actually do it, requires science and math (to ship vaccines, to go to Mars, to build that bridge...) to figure out : How Much , When, How, do we need to protect it from heat cold, vacuum, and to answer many other such questions. So math is all around us. They say it is the language of Science - you cannot do science without counting and calculating. BY the way, I am really impressed that , as a fifth grader, you are on the Web, researching for your paper. It is such a fast and technologically advanced way to gather information. In fifth grade, I was doing well to open an encyclopedia. ********** What kinds of things do you do to test astronaut clothing for heat? How has the clothing changed from the first walk on the moon to space suits now? The space suits have gotten better - better joints at elbows, better temperature control. lighter. Better air systems. I thought the space craft was set to a certain temperature. How come you have to make sure their clothing doesn;t get too hot? How hot is it in space? What is the insulation in a space craft made of? Silica tiles, (the same material sand is made of ) , Silica nd Quartz blankets, and , Where it gets REALLY hot on the front tip and edges (above that 3600 F i mentioned) , we use Carbon and Silicon Cabide. What are Silica tiles? The insulation used over most of the Shuttle is Silica tile. these are very light pieces of a special type of ceramic, made of Silica. ordinary sand is 95% Silica . are usually square, and a few inches thick. They are probably called tiles for two reasons 1) they are ceramic, like wall tiles like on a kitchen wall. 2) you have to cover every part of the surface with them, so you put them on the surface close together , just like if you were laying tiles in your kitchen. they method used to cover a surface with small peices is called tiling (or tesselation) and there can be a lot of mathematics involved. How hot does the surfuce get on the entry to the atmosphere? Does the insulation ever beark? Up in space the black stuff is about 3 degrees Kelvin - really cold! but because we (that is, that spacecraft or satellite) is near the sun and the earth , it is a balmy 50 degrees Kevin, or ! -370 Fahrenheit (yes minus!!). So when the astronauts take a spacewalk, it is darn cold out there, and their suit is like a very warm blanket. When a spaceship comes back to earth, the outer surface heats up to 3600 degrees Fahrenheit or so, and we use very good insulation to keep the astronauts from burning up. The inside of the ship is kept at reasonable temperatures for the people. If you saw that wonderful movie, Apollo 13, The only reason it got so cold inside the ship is they had to divert energy from the heaters to survive and get back home. What is Kelven - is a space term for temperature? Kelvin = absolute temperature scale . Zero Kelvin = -460 fahreheit. at zero Kelvin, the atoms dont move around at all, everything is frozen. Was the part of Apollo 13 realistic, did that really happen with the heat problem? That temperature thing in APollo 13 really did happen. Amazing, isnt it? ********** What are you wokring on right now? Does it have to do with Mars? Is NASA working on sending astronauts to Mars? Mars - everyone at NASA is excited about Mars, for many reasons. There are several possible missions planned. To send people, they currently plan to send spacecraft first that the peopel will use when they get there. The spacecraft may set up and start produciong fuel for the return trip to earth. ********** How old is your daughter ? Will you have any more children? Will you continue to work? do you ever feel like being a stay at home mom? My daughter is 2 1/2. I would like to have another child, but at age 41, it isnt so easy. Still we try. I will continue to work. It is more interesting, they pay me so much that it makes more sense to work, and fundamentally i personally dont want to be full time mother. My mother stayed home with 8 kids, and it didnt look like any fun to me - or to my sisters. I notice that my brothers had kids, but none of my 4 sisters had kids. I was aking some otehr working mothers about this the other day , because some want to stay home, others would rather do anything else. It seems to relate to how we saw our mothers lives. My mother was fine with us,, but i think that " That has been done, I would rather try something different" Do you also think that it would be easier to stay at home if you hadn't already been in a NASA career? I mean if you didn't know any better? I really never was interested in staying home with kids, and never particlarly planned to have kids. My earliest ambitions were to be a writer in the Nothwoods, an International reporter, Forestry, all kinds of things. When i got older, and developed an interest in the opposite sex, i added in a husband into my daydreams. When I was your age , i never saw any women with kids who lived an interesting life, so i figured that i would skip the kids. And i kept following my interests in school, which led me into science and math in high school, and finally in college, i went into enginering because i wanted to solve real-life problems and to earn a living at doing that. Rather than working at some unrelated job, and helping to solve problems through social activism at night. ********** How do you keep up with all the changing technology? Do you take classes or do you learn from your work? I used to take classes, and plan to start again soon. and i read papers that other researchers write about their work and go to meetings where people tell each other what they are working on. What was the turning point after all the other jobs you had to make you want to go back and pursue a job at NASA? Wow . great question. It was the activism thing. Of course, i wanted to become an Environmental engineer to work on pollution problems, , and i didnt. Materials Science suited my own interests and abilties better. I care more about physics and chemistry than i do about pollution in dumps.. ********** Do you think you will stay at NASA? What other kinds of jobs could you get now if you wanted to change careers? There are so many wonderful aspects of my job, that if i had ever suspected i would work here, i would have been more cheerful about my job search. If i left NASA, i might be able to work on similar work for some of the large companies who do this kind of work, but women and minorities don't fare well in big old beaurocratic organizations ( the glass ceiling, you know) so i would do better to form a new small company and work on narrow projects. Whne i retire, though, i want to run a climbing quipment shop or do research and Rescue in the SIerra Nevada mountains, because i met my husband while Mountaineering, and we would like to spend more time in the mountains.