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Wired for Space
Jeff Gordon Few things are as exhilarating as heading around the racetrack at just under 200 miles per hour. Hi. Welcome aboard the number 24 Dupont Chevy Monte Carlo. I'm Jeff Gordon. It takes a lot to win a NASCAR race like science, technology and math. There's a whole lot more to it than just counting laps. You also need plenty of something else FUEL! During an average race, my racecar burns 100 gallons of fuel. Guess how many gallons this car uses? NONE instead it uses electricity! NASA is working on cutting edge technology using electricity to propel a spacecraft instead of using fuel. To do that, NASA will use the power of math, science, and technology, but hold on race fans, theres a string attached. Ladies and gentlemen start your engines for this episode of NASA CONNECT! Van Hughes Hi! And welcome to NASA CONNECT, the show that connects YOU to the World of math, science, technology and NASA! I'm Van Hughes Jennifer Pulley and I'm Jennifer Pulley. We're here at the Disney-MGM Studios in Orlando, Florida. Were your hostsalong with Norbert. Every time Norbert appears, have your cue cards from the lesson guide and your brain ready to answer the questions he gives you. And teachers, every time Norbert appears with a remote thats your cue to pause the videotape and discuss the cue card problems he gives you. Announcer Fasten your seatbelts.
Jennifer Pulley Todays show features FUN ways to learn math. Well see how NASA researchers collect and measure data, recognize patterns, develop functions and use algebra to solve their problems. Van Hughes Then they compare the results and actually make predictions of how the technology will perform in the environment of Space. Plus, youll get to simulate NASA research and learn how magnetic forces cause motion. And youll be doing this in your classroom. Its going to be a thrilling ride. Jennifer Pulley Later, our NASA Headquarters correspondent, Dr. Shelley Canright, will get you hooked up to this shows web-activity. Todays NASA CONNECT program features Patterns, Functions, and Algebra to get you Wired for Space! Van Hughes Did you know that everyday at NASA, the researchers use math, science, and technology everyday to make space transportation safe and reliable? Jennifer Pulley That's right, and more affordable too. Van Hughes You know, NASA CONNECT has sent us to some pretty cool locations .but Disney-MGMs Rock n Roller Coaster starring Aerosmith is definitely a gas! Jennifer Pulley Not "gas," Van, it uses state of the art electromagnetic motors. Van Hughes Electromagnetic? You mean this roller coaster uses electricity and magnetism to run???
Jennifer Pulley Exactly! Electricity is one of the four fundamental forces of nature that we use to make things work for us. Magnetism is the force of attracting or repelling magnetic materials. Magnets have the power to pull things toward them but they can also push or repel things away. When you connect the power of electricity, with the strength of magnetism, you can make an electromagnetic motor -- like the one that gets your clothes clean in the washer. Today, we're showing how electricity is used for what you might call another type of spin cycle -- propelling spacecraft in orbit! Van Hughes So, what does this roller coaster have to do with NASA and spacecraft? Not that I'm complaining, and by the way, think they'll let us ride again? Jennifer Pulley Well Van, NASA is working on a way to propel spacecraft into orbit and get this! They are using a track similar to this roller coaster track!! Lets propel ourselves over to NASA Marshall Space Flight Center in Huntsville, Alabama and check it out! Van Hughes So, this is like a roller coaster, Jen? Where are all the loops and stuff? Jennifer Pulley Well, it's not like a roller coaster in that way, but it does use some of the same scientific principles. This is engineer Jose Perez to tell us more.
Jose Perez Thanks Jennifer, getting into space is expensive, and the first part of the trip costs the most. That's where this track comes in; it's used for magnetically propelling a spacecraft. Like magnets, electricity has a similar push and pull, called charges. In fact, electricity and magnetism are a lot alike because they are really the same force of nature. Were just used to thinking of them as two different things. Thats where MagLev or Magnetic Levitation comes in. Van Hughes Ok so what is magnetic levitation? Jose Perez Magnetic Levitation or MagLev is a new technology being developed for high speed trains. Instead of running on metal wheels, these new trains float or levitate above the track. Jennifer Pulley How does that happen? Jose Perez Electromagnets in the track levitate and propel the vehicle down the track without any direct contact. Van Hughes Cool! Okay, I get it. Electrical charges are like magnetic poles that repel each other and that's what pushes it down the track. Jose Perez Exactly, the magnetically levitated vehicle would leave the track traveling at around 600 miles per hour and then reach orbit using rocket power. Kid Question What kind of test did they use? Kid Question Were there any patterns in the results? Kid Question What kind of graph resulted from the data? Jose Perez One of the things that we test is how much force is being produced by our electromagnets. To find out the force, we use this equation: F=MA; F is the force, M is the mass and A is acceleration. [Acceleration is the increase of speed over time. We put sensors aboard our test vehicle that measures its acceleration.] Since we already know the Mass of our test vehicle, if we multiply the acceleration by the mass we can determine force. Taking those numbers and producing line graphs we can show the forces on our test vehicle the pattern that develops helps us predict the performance for future space vehicles. Van Hughes Wow, thats a really exciting way to understand math. You work with math like that everyday at NASA, right? Jose Perez Yes and we also share our results with people in industry and at other NASA Centers. By looking at our results they can understand how much the carrier is accelerating and how much force the track is making Because we speak the common language of mathematics we can share what we learn; and learn from each other. Jennifer Pulley So you see, NASA is using electromagnets and this track to help them develop ways to move or propel a spacecraft into orbit. Van Hughes Jen, wasn't there another way to propel spacecraft that involved magnets and wires, string or something? Jennifer Pulley Well Van, youre right in a way. NASA is working on other really cool ways to use electricity and magnetism to propel a spacecraft like using tethers. Okay, first a few basics a tether is a string, a rope or a wire. Some everyday examples of tethers are: the string that keeps a paddleball on a paddle, a fishing line that keeps the fish on the pole and even a leash that keeps a dog close to its owner. Van Hughes Maybe you can even think of some more examples. You know, NASA has been using tethers and conducting experiments in space for years. Jennifer Pulley You're right. In fact, in the 1960's, the Gemini astronauts used tethers to connect their spacecraft to another unoccupied rocket.
Van Hughes The 1960's?? Far out Man! Over the years, NASA has learned that connecting two spacecraft together opens up a whole new world of possibilities like propelling a spacecraft. One person who can tell us all about tethers in space is physicist Les Johnson with NASA's Marshall Space Flight Center. Les Johnson We are testing a new kind of propulsion system for space that does not need any rocket engines or fuel. Instead, It will use the Earths magnetic field to help push and pull on spacecraft. Jennifer Pulley All magnetic objects form invisible lines of force that extend between the poles of the object. A magnetic field is the space around the magnet where you feel its force. Magnetic field lines radiate between the Earths North and South Poles and between the poles of magnets. Les Johnson "Basically, the Earths magnetic field works with a special type of wire or conductor called an electrodynamic tether to push or pull an object. The electrons that make up the electric current flowing through the conductor will experience a force when they move through a magnetic field like the Earths. Since they are trapped in the conducting wire tether, the force will be applied to the tether and to whatever is attached to it. Depending upon the direction in which the current is flowing, this force can be a push or a pull - either lowering or raising a spacecrafts orbit." Jennifer Pulley So the direction of the current determines whether it's pushing or pulling Van Hughes And the more current the more force.
Les Johnson Right. In fact, NASA Marshall is working on a project called ProSEDS which uses the Earth's magnetic field to push or pull on the attached tether. When the tether moves so does the spacecraft. Jennifer Pulley What does ProSEDS stand for? Les Johnson ProSEDS stands for Propulsive Small Expendable Deployer System. Space exploration is limited largely by the cost of launching payloads -- finding a cheaper way to explore space is always very important to us. Typically, a rocket will place its payload into low Earth orbit and from there, propellant-fueled thrusters have to boost it to a higher altitude. ProSEDS is one experiment that focuses on technology to cut the expense of placing a payload into its final orbit. Van Hughes Sounds like ProSEDS can provide an alternative to using rocket engines and lots of fuel? Les Johnson Absolutely. Electrodynamic tethers could one day be used as a cheap, lightweight, and reliable way to remove space junk from orbit; keep the International Space Station in orbit; and even power missions to other planets. Van Hughes WOW, this could get us to other planets? Les Johnson Tethers offer us unlimited possibilities Van and thats why Im all CHARGED up about this Project. Jennifer Pulley Les, Charged up is what kids in Baton Rouge, Louisiana, got about the student activity for today's program.
Student Group Hi, We're from Istrouma Middle Magnet School in Baton Rouge, Louisiana Nasa Connect has asked us to help you understand how to do the student activity for this program. Earlier, we learned that the NASA ProSEDS experiment uses long, conducting wires called tethers. The tethers make electricity that can be used to move satellites. Now we're going to simulate the research they do at NASA by constructing and using the "Make It Go" electrodymanic demonstration unit or EDU for short. (pause) First let's make the EDU! The materials you need, magnets, batteries, wire, and very small light bulbs, called light emitting diodes. Remember, safety is our number one concern at NASA, so be sure to listen carefully and follow the safety guidelines. Now that the EDU is made, You'll need to make an electrical current controller for the EDU. The current controller is made using only regular paper and a set of five resistors. A pattern for the current controller can be found in the lesson guide. Be sure that all your wires are connected correctly. This will create what is called a "closed" circuit that allows the electricity to flow freely through the EDU. Now you're ready to observe and predict what happens to the light from the LED when you change the amount of electricity flowing through the circuit of your EDU. If the wires are not connected properly, an "open" circuit exists and the flow of electricity through the EDU is broken. Conduct the tests and record your observations on your data sheet. Were your predictions correct? As a class, discuss whether there's a pattern to describe what happens to the brightness of the light when the electricity level increases. (pause) The EDU is a model of the actual propulsion system tested in the ProSEDS mission. You'll use the EDU to observe and understand that if a wire has electricity flowing through it, the wire can actually move if it is placed near a magnet. You'll measure, record, and graph the relationship between the electric current and wire coil movement. Then, you'll analyze the results just like NASA researchers do! Change the current levels and measure and record the distance that the wire coil moves at each level. Each time you test a new current level, compare the results with your classmates. Average the test results at each current level. After you've completed testing, your teacher will get you started on graphing your data, then help you understand how to analyze your results!
Teacher Great work. But how can we display the data we collected on a graph? Think about the information we are comparing. Now that we have our graph labeled, one person from each group should come up and graph the average distance the coil moved at each current level This looks great! What type of graph is this, a bar graph, a line graph, a scatter plot? What was the maximum distance our wire coil moved? What current level produced the greatest movement? Why do you think this is so? Class, can you guess which electricity level the circuit is set on, based on how far the wire coil is moving? Student If I run some more tests, I know I can find out! Class YEAH! Let's "Make it Go " again! Van Hughes Man, those kids looked like they were really having fun Jennifer Pulley and learning a lot too! Les Johnson Just like NASA CONNECT teamed up with a school to learn about electromagnetism. NASA has teamed up with a university to better understand propulsion in space Jennifer Pulley Lets go to the University of Michigan to see what theyve been working on. Brian and Jane Im Dr. Brian Gilchrist with the University of Michigan in Ann Arbor, and Im Jane Ohwiller, a graduate student in Space Systems here at the University.
Brian My students were asked to design, build, and test a very small satellite that could be used to support NASAs ProSEDS tether mission. ProSEDS is demonstrating a new kind of propulsion system for space that does not need any rocket engines. It uses the Earth's magnetic field to push and pull on spacecraft. ProSEDS will pull down a large used up rocket stage. Jane We named the satellite Icarus, from Greek mythology. As you may know, Icarus, the son of Daedalus in escaping from Crete on artificial wings made for him by his father, flew so close to the sun that the wax with which his wings were fastened melted, and he fell into the Aegean Sea. Our mission will be successful if ProSEDS can rapidly pull down the rocket stage, which will ultimately burn-up in our atmosphere. Falling from the sky just like Icarus. The Icarus satellite will help pull 15 kilometers of tether from its deployer and then use instruments onboard to measure the location of the tether and attitude of our spacecraft. Kid Question Did she say ATTITUDE? Jane Not like that. I mean the position of the spacecraft relative to Earth. Brian Right Jane, the students designed this satellite to collect this information and transmit the data to the ground. Mission scientists will use this information to better understand the dynamics of tether systems. Jane To build our satellite, we used computer design tools and a lot of discussions and tutoring from experienced engineers and faculty at Michigan, the NASA Marshall Space Flight Center, and from industry partners such as TRW. After the design work, various mechanical and electrical components were purchased or built. These pieces were carefully put together, and then we were able to begin a long series of tests to see if it was going to work the way we wanted it to.
Brian At the same time we were designing the hardware, we were developing the computer software. Not everything worked the first time, as is typical of anything new being developed, so we had to consider what could have gone wrong, read through notes and journals to check that we did everything right, and then try again. And sure enough, some changes had to be made to get it ready for delivery and flight. Each step required careful planning to accomplish the special tests that Jane mentioned. Sometimes it was as simple as weighing the satellite. Other tests involved special equipment such as sensors to measure the performance of our solar cells. The tests were done here in our labs at Michigan and at the Marshall Space Flight Center. One test even required putting the satellite on a large vibration stand that shook it really hard to prove it could survive the launch. Van Hughes How did you gather the data? Jane Electronic sensors were often used in our tests to make the critical measurements necessary to know that the Icarus satellite was still working correctly, but other data collection involved just looking at the satellite to see that, for example, our solar cells were not broken, and sometimes we had to measure how much power the solar panels could generate or how much power our radio transmitter was sending to its antenna. The mathematical data was either read off of electronic instrument displays or automatically collected and stored on computers and then made into graphs. Van Hughes Wait a minute theyre in Michigan and Jennifer Pulley Were at the Marshall Space Flight Center in Huntsville, Alabama, how did they do that? Brian Good communication is really important on a project that involves people located far away. When the satellite was being designed, we communicated with our NASA partners through presentations, written reports, and email on the internet. By using patterns, functions, and algebra, they were able to prove to themselves and NASA that the Icarus satellite was ready for flight. Being able to understand data and other information in the form of graphs and charts is a lot easier than descriptions. Mathematics is really like another language, one all of our partners need to understand to be able to work together. Kid Question How was algebra used to find the solution? Kid Question How are arrays used in algebra? Kid Question What algebraic equation shows that voltage is related to current? Van Hughes Guys, meet Leslie Curtis, She's an engineer here at NASA Marshall. Leslie Curtis Thanks Van, Dr. Gilchrist is right. Mathematics is one of the most powerful tools that we have available to us at NASA. We use Algebra almost everyday to find solutions to problems. The Icaurus satellite that Jane told us about uses solar cells to charge its batteries. Solar cells, which convert sunlight into electricity, are arranged in a pattern called a solar array. One of the ways that equations can be written in algebra is also called an array, or matrix. Actually, they look a lot alike. Lets compare them. Heres an example of an array used in algebra. Notice the pattern of rows and columns. Now, heres a picture of a solar array. See the rows and columns again? Lets use the solar arrays on the Icarus satellite to do a simple math problem that the students at the University of Michigan were faced with. Then, let's compare solar arrays with algebraic arrays. The Icarus satellite uses 12 volt batteries. Voltage is a measure of electricity. If we use a solar array to charge our batteries, we know from science that we need to have a solar array voltage that is slightly higher than the 12 volt batteries, so lets say 15 volts. Since each Icarus solar cell provides 0.5 volts of charge, how many cells do we need for our solar array to produce 15 volts? To calculate the number of solar cells wed need, we use algebra. If we solve for c which stands for cells. We see that it will take 30 cells to give us 15 volts to successfully charge the batteries. From this information we can arrange our solar cells in a solar array pattern. Van Hughes Cool! Like 10 cells wide and 3 high!
Jennifer Pulley yEA! Or 15 cells wide and 2 cells high! Leslie Curtis So you see, when scientists are trying to calculate complicated equations, we often write them in the pattern of an algebraic array. Jennifer Pulley OK, I see how you came up with the pattern of the solar array, but how long does it take the solar cells to charge Icarus batteries? Leslie Curtis That question can be answered using Algebra too. We know that the charge on the Icarus satellite batteries is related to current and time. Current is another measure of electricity which we express in units called amperes, or amps for short. Now, to calculate the amount of time needed to charge the batteries, we use the following equation. Charge is equal to current times time. Since we want to know the length of time needed to charge the batteries, we can rewrite the equation as time is equal to charge divided by current. The Icarus satellite batteries have a maximum charge capacity of 2.5 amp-hrs. A typical charging current that we might use to charge the system is 0.5 amps. So if the charge is 2.5 amp-hours and the current is 0.5 amps the equation can be written this way: Time= 2.5 amp-hour/0.5 amps. Solving for time, we can see that the time required to reach full charge on the system is 5 hours. Van Hughes Lets see if Ive got this straight. We used voltage as a way of measuring electricity when talking about the solar array, and current to describe electricity when we calculated the amount of time it took to charge the batteries. But how are they related? Leslie Curtis Voltage and current are related by the simple equation "V" equals "I" "R". V stands for voltage which is usually measured in volts. I is the current which is usually measured in amps, and R is called the resistance. The resistance is measured in units called ohms. The equation V=IR is actually called Ohms law after G.S. Ohm, a German scientist, and the unit of resistance was named in his honor.
Voice of Ohm You juzt vouldn't believe sie r-r-r-r-resistance I got. Shocking! Van Hughes I think its really sweet that university students used Algebra to work with NASA on the ProSeds experiment. But Im not sure I get this volts, and amps, and resistance---oh, my! Jennifer Pulley Sorry. Couldn't RESIST. Nor could we resist the chance to meet some students who teamed up with NASA CONNECT and are wired for todays web-based activity. Dr. Shelley Canright Hey gang hey Norbert, welcome to St. Louis, Missouri. I'm standing in front of the SLSC, our museum partner for this show. This science center is a 232K square foot, three building facility connected by a brdge and a tunnel. It contains 11 galleries and over 650 exhibits, an OMNIMAX theater, Planetarium, Discovery room, outdoor science park, and live science presentations. In a moment we'll go inside to meet students from the Compton-Drew Investigative Learning Center and the AIAA student chapter from the University of Washington-St. Louis. These students will highlight the web-based activity that complements this NASA Connect video program. But first, let's take a quick fly-by of Norberts on-line lab. There's a couple of areas of this lab worth investigating. Teachers, Lab Manager is designed especially for you. Within Lab Manager, you will find scenarios and tools for integrating Connect's web activity in the classroom. Another excellent resource for integrating technology efficiently into the curriculum is the E-pals Classroom Exchange. As a Connect partner, it offers free web-based email and an on-line classroom community of over 130 countries with whom you may communicate and collaborate on class projects, such as those suggested in the Connect Programs. Well, here we are now inside the SLSC and waiting to take us into the wild blue yonder of the internet and this Connect show's web activity are our guest middle school and University students. The web module that they will share has been contributed by Princeton University's Interactive Plasma Physics Education Experience, or IPPEX. IPPEX has created several interactive physics modules including one on Electricity and Magnetism. This module will introduce you to many of the basic concepts involved with electricity and magnetism like static charge, moving charge, voltage, resistance, and current. This site combines multimedia with built-in interactive exercises to help you better understand the concepts. For instance, you can rub a balloon on a wool sweater to learn about static electricity. Use a slider bar to see what happens with similar charges on balloons. Build and complete a circuit! So there you have it. Take a web site add interactivity, subtract complexity, multiply excitement. The E-Solution is simple, Norbert's On-Line Lab its where education clicks. Bringing you the power of digital learning, I'm Shelly Canright for NASA Connect On-Line. Jennifer Pulley Well, that's all we have time for today. Van Hughes Thanks to everyone who made this NASA CONNECT program possible. Jennifer Pulley We hope you've all made the "connection" between the NASA research that will help-- propel a spacecraft without the use of fuel and the math, science, and technology you do in your classroom! Van Hughes Jennifer and I would love to hear your comments, questions or suggestions! Write us at: NASA CONNECT NASA Langley Research Center Mail stop 400 Hampton, VA 23681 Or send us an email at connect@edu.larc.nasa.gov Jennifer Pulley Hey teachers! If you would like a video tape of this program and the accompanying lesson guide, check out the NASA CONNECT web site. From our site, you can link to CORE, the NASA Central Operation of Resources for Educators. Or link to the NASA Educator Resource Center Network. Van Hughes Until next time, stay Jennifer Pulley connected to Van Hughes math, Jennifer Pulley science, Van Hughes technology Jennifer Pulley and NASA!! See you then!!
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