1 00:00:30,000 --> 00:00:45,040 Hello, I'm Patty Wagstaff. 2 00:00:45,040 --> 00:00:49,800 As a champion aerobatic pilot, I compete with gravity almost every single day. 3 00:00:49,800 --> 00:00:53,800 If it weren't for my skills and aircraft, it would be an uneven map. 4 00:00:53,800 --> 00:00:56,440 I enjoy the challenge of flying fast. 5 00:00:56,440 --> 00:00:59,120 The NASA team faces challenges, too. 6 00:00:59,120 --> 00:01:03,480 They encourage us all to push our knowledge and skills to a higher level. 7 00:01:03,480 --> 00:01:07,280 My airplane flies over 200 miles per hour. 8 00:01:07,280 --> 00:01:11,200 How fast do you think astronauts have to go to reach Earth orbit? 9 00:01:11,200 --> 00:01:12,200 2,000? 10 00:01:12,200 --> 00:01:13,200 10,000? 11 00:01:13,200 --> 00:01:16,200 How about over 17,000? 12 00:01:16,200 --> 00:01:21,320 That's right, 17,500 miles per hour. 13 00:01:21,320 --> 00:01:23,000 Speed isn't the only challenge. 14 00:01:23,000 --> 00:01:25,120 Safety is very important. 15 00:01:25,120 --> 00:01:28,440 And making spaceflight less expensive is another. 16 00:01:28,440 --> 00:01:32,960 To be a part of the team tackling these challenges, you'll need to do well in school, especially 17 00:01:32,960 --> 00:01:36,520 in math, science, and technology. 18 00:01:36,520 --> 00:01:41,000 On today's NASA Connect, we'll be working with NASA scientists and engineers to explore 19 00:01:41,000 --> 00:01:45,880 the technologies that will be needed by the next generation of space explorers. 20 00:01:45,880 --> 00:01:47,200 That's you. 21 00:01:47,200 --> 00:01:53,080 So, get ready to take off with your hosts, Jennifer Pulley and Dan Giroux, on this episode 22 00:01:53,080 --> 00:01:54,160 of NASA Connect. 23 00:02:23,800 --> 00:02:29,240 Hi, I'm Jennifer Pulley, your host, along with Dan Giroux, who's joining us remotely 24 00:02:29,240 --> 00:02:32,600 from the NASA Langley Research Center in Hampton, Virginia. 25 00:02:32,600 --> 00:02:36,320 You know, we're real excited to be here at the U.S. Space and Rocket Center in Huntsville, 26 00:02:36,320 --> 00:02:39,280 Alabama, for part of this NASA Connect. 27 00:02:39,280 --> 00:02:43,000 Teachers, make sure you have the educator guide for today's program. 28 00:02:43,000 --> 00:02:45,200 It can be downloaded from the NASA Connect website. 29 00:02:45,200 --> 00:02:51,600 In it, you'll find great math-based, hands-on activities and information on our instructional 30 00:02:51,600 --> 00:02:53,840 technology components. 31 00:02:53,840 --> 00:02:58,840 On this episode of NASA Connect, we're visiting NASA Marshall Space Flight Center in Huntsville, 32 00:02:58,840 --> 00:02:59,840 Alabama. 33 00:02:59,840 --> 00:03:05,280 There, we'll meet NASA scientists and engineers who are exploring the challenges of building 34 00:03:05,280 --> 00:03:08,480 the next generation of reusable spacecraft. 35 00:03:08,480 --> 00:03:12,240 My friends here are going to help me figure out what it takes to get into orbit. 36 00:03:12,240 --> 00:03:13,320 How can we do that? 37 00:03:13,320 --> 00:03:18,200 By learning how NASA is getting spacecraft into orbit more safely and less expensively. 38 00:03:18,200 --> 00:03:20,240 Can't we just keep doing it the way we always have? 39 00:03:20,880 --> 00:03:25,520 Well, you know, things change and we need to change in order to continue our journey 40 00:03:25,520 --> 00:03:27,000 of exploration. 41 00:03:27,000 --> 00:03:33,820 Just think, we went from the Wright Brothers' first flight in 1903 to landing on the moon 42 00:03:33,820 --> 00:03:35,680 in 1969. 43 00:03:35,680 --> 00:03:40,240 As you can see, people have been dreaming of flight for ages. 44 00:03:40,240 --> 00:03:46,280 One of those dreamers was American Robert Goddard, an early experimenter with rockets. 45 00:03:46,320 --> 00:03:50,800 Goddard's work continues to inspire generations of scientists. 46 00:03:50,800 --> 00:03:57,240 These rockets are the results of Goddard's and other pioneers' imagination and hard work. 47 00:03:57,240 --> 00:03:59,280 Now it's your turn. 48 00:03:59,280 --> 00:04:01,480 You are the next generation of space explorers. 49 00:04:01,480 --> 00:04:03,040 Whoa, that's way cool. 50 00:04:03,040 --> 00:04:04,520 I know, it really is, Zach. 51 00:04:04,520 --> 00:04:10,120 And you know, just as the early space programs of NASA like Mercury, Gemini, and Apollo led 52 00:04:10,120 --> 00:04:14,520 us to the shuttle, the shuttle leads us to the next generation of spacecraft. 53 00:04:14,520 --> 00:04:15,720 What's that? 54 00:04:15,720 --> 00:04:17,680 That's what this show is all about, Seema. 55 00:04:17,680 --> 00:04:19,400 All right, okay, I'm pumped. 56 00:04:19,400 --> 00:04:21,440 But how do we get these heavy rockets off the ground? 57 00:04:21,440 --> 00:04:23,200 You know, Zach, that's a really good question. 58 00:04:23,200 --> 00:04:25,360 And what do we mean by the word heavy? 59 00:04:25,360 --> 00:04:30,160 Well, what we call heavy is just a way of measuring gravity. 60 00:04:30,160 --> 00:04:33,360 Gravity is a force of attraction between objects. 61 00:04:33,360 --> 00:04:36,720 Everything in the universe is attracted to everything else. 62 00:04:36,720 --> 00:04:39,200 Sometimes it's powerful, but sometimes it's weak. 63 00:04:39,200 --> 00:04:42,800 The amount of attraction really depends on the mass of the objects. 64 00:04:42,800 --> 00:04:43,800 Mass? 65 00:04:43,880 --> 00:04:46,880 You owe me a soda. 66 00:04:46,880 --> 00:04:49,800 Hey, Zach, pick Cassie and I up one, too. 67 00:04:49,800 --> 00:04:51,840 Mass is not the same as weight. 68 00:04:51,840 --> 00:04:55,600 Think about how astronauts become nearly weightless in space. 69 00:04:55,600 --> 00:05:00,360 When they are on the moon, they weigh only one-sixth of their weight on Earth. 70 00:05:00,360 --> 00:05:06,320 For example, a man who weighs 180 pounds on Earth would weigh 30 pounds on the moon. 71 00:05:06,320 --> 00:05:07,320 They didn't shrink, did they? 72 00:05:07,320 --> 00:05:10,560 Their mass is the same, so what causes their weight to change? 73 00:05:10,560 --> 00:05:11,560 Gravity. 74 00:05:11,880 --> 00:05:14,400 The force of attraction between objects. 75 00:05:14,400 --> 00:05:18,600 On Earth, we feel gravity because of Earth's mass. 76 00:05:18,600 --> 00:05:22,040 Weight is just how we measure gravity's pull on things. 77 00:05:22,040 --> 00:05:26,840 In space, gravity is less because we are further away from the Earth's mass. 78 00:05:26,840 --> 00:05:31,720 The further away from a large mass like our Earth, the less gravity, and therefore the 79 00:05:31,720 --> 00:05:32,720 less weight. 80 00:05:32,720 --> 00:05:35,520 What does this have to do with building a spacecraft? 81 00:05:35,520 --> 00:05:36,520 Everything, Zach. 82 00:05:36,520 --> 00:05:39,280 The mass of a spacecraft determines its weight. 83 00:05:39,400 --> 00:05:43,120 The more a spacecraft weighs, the more force is needed to reach orbit. 84 00:05:43,120 --> 00:05:44,120 Force? 85 00:05:44,120 --> 00:05:45,680 I thought we were talking about gravity. 86 00:05:45,680 --> 00:05:48,840 Hmm, okay, I think we need to talk about some basics here. 87 00:05:48,840 --> 00:05:54,560 Lucky for us, 17th century English scientist Sir Isaac Newton explained the relationship 88 00:05:54,560 --> 00:05:56,320 of mass to gravity. 89 00:05:56,320 --> 00:06:00,240 He said we need force to overcome gravity. 90 00:06:00,240 --> 00:06:03,840 Newton described this relationship as a series of laws. 91 00:06:03,840 --> 00:06:08,360 Newton helped our understanding of gravity with his first law, what Newton said is easy 92 00:06:08,360 --> 00:06:09,600 to understand. 93 00:06:09,600 --> 00:06:14,040 An object at rest will stay at rest unless a force moves it. 94 00:06:14,040 --> 00:06:17,980 With a spacecraft, we need to come up with the force to move it. 95 00:06:17,980 --> 00:06:21,320 So we need to keep the weight, I mean mass, low, right? 96 00:06:21,320 --> 00:06:22,320 Correct. 97 00:06:22,320 --> 00:06:25,020 Keeping the mass low will mean less weight at launch. 98 00:06:25,020 --> 00:06:29,400 The force of gravity on the spacecraft is equal to the force of the launch pad holding 99 00:06:29,400 --> 00:06:33,120 it up, what Newton called balanced forces. 100 00:06:33,120 --> 00:06:36,480 We have to unbalance these forces to move the spacecraft. 101 00:06:36,480 --> 00:06:37,480 How do we do that? 102 00:06:37,600 --> 00:06:41,600 Well, Cassie, Newton explained in his second law that if a force is applied to a body of 103 00:06:41,600 --> 00:06:45,400 mass, the body will move in the direction of the force. 104 00:06:45,400 --> 00:06:50,280 Newton also described in his third law that for every action, there is an equal and opposite 105 00:06:50,280 --> 00:06:51,640 reaction. 106 00:06:51,640 --> 00:06:54,440 The thrust of a rocket motor is the action. 107 00:06:54,440 --> 00:06:58,200 The reaction is the spacecraft leaving the pad. 108 00:06:58,200 --> 00:07:00,680 Thrust measures the power of a rocket engine. 109 00:07:00,680 --> 00:07:04,880 The thrust must be greater than the force of gravity that keeps a rocket on the launch 110 00:07:04,880 --> 00:07:05,880 pad. 111 00:07:05,880 --> 00:07:13,160 For example, if the thrust, T, of a rocket is 75 kilograms, and the weight of the rocket, 112 00:07:13,160 --> 00:07:21,520 W, is 50 kilograms, then subtracting 50 from 75 would equal 25 kilograms of upward force, 113 00:07:21,520 --> 00:07:28,160 F. To get into orbit, you need to keep the upward force greater than the force of gravity. 114 00:07:28,160 --> 00:07:34,320 When you ride an amusement park ride like the Space Shot here at the Space and Rocket 115 00:07:34,320 --> 00:07:38,360 Center, you are overcoming gravity as you rise up. 116 00:07:38,360 --> 00:07:43,560 At the top, you experience free fall or microgravity, just like the astronauts. 117 00:07:43,560 --> 00:07:48,660 You just don't stay in free fall very long because you drop back downward as the downward 118 00:07:48,660 --> 00:07:52,240 force of gravity becomes greater than the upward force. 119 00:07:52,240 --> 00:07:54,680 That was awesome! 120 00:07:54,680 --> 00:07:58,840 The force of gravity is measured in units called Gs. 121 00:07:58,840 --> 00:08:01,960 At sea level, that force equals 1G. 122 00:08:01,960 --> 00:08:05,720 So we need more than 1G of force to move the rocket? 123 00:08:05,720 --> 00:08:08,480 Pretty much, Seema, but you know, it's not as easy as it sounds. 124 00:08:08,480 --> 00:08:11,360 Let's take the Saturn V rocket of the Apollo program. 125 00:08:11,360 --> 00:08:15,480 Now, how much do you think that rocket weighed at launch? 126 00:08:15,480 --> 00:08:19,560 Remember, how fast a spacecraft needs to travel in order to reach orbit. 127 00:08:19,560 --> 00:08:22,360 Yes, 17,500 miles per hour. 128 00:08:22,360 --> 00:08:26,240 Correct, and that's over 28,000 kilometers per hour. 129 00:08:26,240 --> 00:08:31,440 The Saturn V is taller than the Statue of Liberty and weighed over 6 million pounds 130 00:08:31,440 --> 00:08:32,680 at launch. 131 00:08:32,680 --> 00:08:38,380 The Saturn V's engines had to produce over 7.5 million pounds of thrust to have enough 132 00:08:38,380 --> 00:08:42,400 upward force to overcome the downward force of gravity. 133 00:08:42,400 --> 00:08:43,960 Okay, I get it. 134 00:08:43,960 --> 00:08:47,000 If we keep the weight of the rocket down, we won't need as much engine thrust to move 135 00:08:47,000 --> 00:08:48,000 it. 136 00:08:48,000 --> 00:08:49,000 Right! 137 00:08:49,000 --> 00:08:50,000 You guys are so smart. 138 00:08:50,000 --> 00:08:51,520 You know, engineers deal with this all the time. 139 00:08:51,520 --> 00:08:55,960 They use math to compare the vehicle weight to the thrust of the engines. 140 00:08:55,960 --> 00:08:57,600 Now, this can be written as a ratio. 141 00:08:57,920 --> 00:09:01,160 A ratio is just a simple way of comparing one thing to another. 142 00:09:01,160 --> 00:09:04,640 In this case, vehicle weight compared to thrust. 143 00:09:04,640 --> 00:09:09,640 So let's talk about the Saturn V. Let's say it weighs a million pounds and it produces 144 00:09:09,640 --> 00:09:11,480 a million pounds of thrust. 145 00:09:11,480 --> 00:09:15,440 The ratio for that would then be one to one and wouldn't go anywhere. 146 00:09:15,440 --> 00:09:20,400 The Saturn V engine created 7.5 million pounds of thrust and the vehicle weighed 6 million 147 00:09:20,400 --> 00:09:21,400 pounds. 148 00:09:21,400 --> 00:09:24,840 Yeah, so that's a ratio of 7.5 to 6. 149 00:09:24,840 --> 00:09:27,480 Or let's see, 5 to 4. 150 00:09:27,480 --> 00:09:28,480 Exactly. 151 00:09:28,480 --> 00:09:32,000 Now you see how important it is to build rockets more lightweight. 152 00:09:32,000 --> 00:09:37,520 A couple of ways NASA scientists and engineers tackle this problem is by using lightweight 153 00:09:37,520 --> 00:09:40,800 materials and designing more efficient engines. 154 00:09:40,800 --> 00:09:47,200 Today, NASA is working on the next generation of reusable spacecraft or launch vehicle system. 155 00:09:47,200 --> 00:09:51,120 We call it the Space Launch Initiative or SLI for short. 156 00:09:51,120 --> 00:09:56,540 Later, we'll work with NASA researchers to learn how they deal with these challenges. 157 00:09:56,620 --> 00:10:00,220 But first, let's visit Dan for this show's web-based activity. 158 00:10:00,220 --> 00:10:03,220 Thanks, Jennifer. 159 00:10:03,220 --> 00:10:09,980 Today, we're visiting the Challenger Center in Chattanooga, Tennessee. 160 00:10:09,980 --> 00:10:13,860 The students from the Chattanooga School of Arts and Sciences will be helping us today 161 00:10:13,860 --> 00:10:15,940 on this web-based activity. 162 00:10:15,940 --> 00:10:20,940 The Challenger Center provides students and teachers several simulated space missions. 163 00:10:21,180 --> 00:10:26,820 During the missions, students work as a team to solve problems and apply math, science, 164 00:10:26,820 --> 00:10:29,380 and technology concepts to real-life situations. 165 00:10:29,380 --> 00:10:33,820 Sir, this is Marsden Challenger, message to the comm team, over. 166 00:10:33,820 --> 00:10:38,420 Each year, the center provides over 8,000 students an opportunity to rendezvous with 167 00:10:38,420 --> 00:10:42,700 a comet, work on a space station, or take a voyage to Mars. 168 00:10:42,700 --> 00:10:49,540 We're using the center's computer lab to highlight this episode's web activity. 169 00:10:49,540 --> 00:10:53,860 Earlier today, we talked about the importance of the math concept of ratios to scientists 170 00:10:53,860 --> 00:10:55,300 and engineers. 171 00:10:55,300 --> 00:11:00,260 On the NASA Connect website, you can learn more about ratios by clicking on Dan's domain. 172 00:11:00,260 --> 00:11:05,380 You'll find a link to the show's instructional technology activity, a zone just for teachers, 173 00:11:05,380 --> 00:11:09,060 and a career zone, where you can meet some of our show's guests and learn about their 174 00:11:09,060 --> 00:11:10,180 jobs. 175 00:11:10,180 --> 00:11:15,140 Selecting this show's instructional activity will take you to Riverdeep's Destination Math 176 00:11:15,140 --> 00:11:18,140 Mastering Skills and Concepts 5. 177 00:11:18,140 --> 00:11:22,540 You'll find activities that make learning about ratios fun, and it's free to NASA Connect 178 00:11:22,540 --> 00:11:23,980 educators. 179 00:11:23,980 --> 00:11:25,860 Click on Ratios and Proportions. 180 00:11:25,860 --> 00:11:30,660 Teachers, you'll find a variety of clever ways to teach about ratios. 181 00:11:30,660 --> 00:11:35,480 From the Connect website, you can also order a great CD that will have you designing your 182 00:11:35,480 --> 00:11:39,180 own planes and learning more about ratios in no time. 183 00:11:39,180 --> 00:11:43,100 Just select the Exploring Aeronautics CD from NASA's Core website. 184 00:11:43,100 --> 00:11:47,780 On the main menu, you can select the Resource Center to find out about the history of flight, 185 00:11:47,780 --> 00:11:51,540 or pick the Activity Center to learn more about lift and drag. 186 00:11:51,540 --> 00:11:56,620 Jennifer, I've been having fun designing aircraft using the Exploring Aeronautics CD. 187 00:11:56,620 --> 00:12:01,780 So tell me, what have you found out about the next generation of reusable spacecraft? 188 00:12:01,780 --> 00:12:03,780 You know, the one I'll be driving. 189 00:12:03,780 --> 00:12:06,100 Wait a minute, Sports. 190 00:12:06,100 --> 00:12:09,220 Don't you have to finish school and a few other things first? 191 00:12:09,220 --> 00:12:10,220 Oh yeah. 192 00:12:10,220 --> 00:12:13,100 I mean, I think so. 193 00:12:13,100 --> 00:12:14,900 Okay, okay. 194 00:12:14,900 --> 00:12:17,380 I'll get back to work on that. 195 00:12:17,380 --> 00:12:20,340 Okay, you do that. 196 00:12:20,340 --> 00:12:24,740 Meanwhile, we've got a lot of work to do, and Norbert's going to help me out. 197 00:12:24,740 --> 00:12:30,780 What is a reusable launch vehicle, or RLV? 198 00:12:30,780 --> 00:12:33,100 Why do spacecraft need to be lightweight? 199 00:12:33,100 --> 00:12:37,020 How is the RLV protected during re-entry? 200 00:12:37,020 --> 00:12:38,380 Those are some good questions. 201 00:12:38,380 --> 00:12:40,940 Now let's get some answers from Kathy Kynard. 202 00:12:40,940 --> 00:12:42,940 She's an engineer here at NASA Marshall. 203 00:12:42,980 --> 00:12:47,980 Kathy, what are some of NASA's design challenges for the next generation of spacecraft? 204 00:12:47,980 --> 00:12:52,580 Jennifer, we have a great bunch of talented folks from around the country helping us choose 205 00:12:52,580 --> 00:12:54,020 the best design. 206 00:12:54,020 --> 00:12:58,060 Some work for the government, some work for private companies, and others for universities. 207 00:12:58,060 --> 00:13:03,180 SLI is designing the whole system for the next generation of reusable launch vehicles. 208 00:13:03,180 --> 00:13:06,460 Okay, we keep saying next generation. 209 00:13:06,460 --> 00:13:07,460 What was the first generation? 210 00:13:07,460 --> 00:13:08,460 Good question. 211 00:13:08,460 --> 00:13:12,580 The Space Shuttle is the world's first reusable launch vehicle. 212 00:13:12,580 --> 00:13:15,620 The Space Shuttle orbiter is designed to be launched again and again, so it is our 213 00:13:15,620 --> 00:13:19,900 first generation of reusable launch vehicles, or RLV. 214 00:13:19,900 --> 00:13:22,780 And that's why we talk about the next gen RLV. 215 00:13:22,780 --> 00:13:25,780 So what are some of the things you're doing to get ready for the replacement of the Space 216 00:13:25,780 --> 00:13:26,780 Shuttle? 217 00:13:26,780 --> 00:13:29,140 Well, the most important thing is safety. 218 00:13:29,140 --> 00:13:33,940 The challenge is to make the vehicle as light as possible without reducing safety or strength. 219 00:13:33,940 --> 00:13:35,700 Yeah, that's understandable. 220 00:13:35,700 --> 00:13:38,500 So I guess being lightweight isn't the only thing that matters. 221 00:13:38,500 --> 00:13:39,500 That's right. 222 00:13:39,500 --> 00:13:43,140 The weight might actually be heavier if, say, it made the whole system safer or less 223 00:13:43,140 --> 00:13:44,820 expensive to operate. 224 00:13:44,820 --> 00:13:49,220 The weight increase might reduce costs and help make the crew travel safer. 225 00:13:49,220 --> 00:13:54,880 We definitely want to keep space travel routine and safe for those next generation space explorers. 226 00:13:54,880 --> 00:13:59,180 There are many things for the SLI program to consider and test. 227 00:13:59,180 --> 00:14:03,700 Different types of engines, fuels, and vehicle shapes, and these are only some of the parts 228 00:14:03,700 --> 00:14:04,940 of the entire system. 229 00:14:05,660 --> 00:14:09,780 We call the whole system the architecture, and we mean everything from mission planning 230 00:14:09,780 --> 00:14:14,540 to launch on orbit support to landing and getting the vehicle ready to fly again. 231 00:14:14,540 --> 00:14:16,660 Kathy, that sounds pretty challenging. 232 00:14:16,660 --> 00:14:20,140 Well, so have you come up with any designs yet? 233 00:14:20,140 --> 00:14:24,220 First we had to decide what we wanted to do in space before we started designing. 234 00:14:24,220 --> 00:14:29,220 NASA sees the next generation RLV as doing two main things, getting to the International 235 00:14:29,220 --> 00:14:32,860 Space Station and taking satellites into orbit. 236 00:14:32,860 --> 00:14:36,220 We select preliminary designs that best meet our needs. 237 00:14:36,220 --> 00:14:40,100 One challenge vehicle designers face is what type of engine to use. 238 00:14:40,100 --> 00:14:42,820 Some engines use kerosene and liquid oxygen. 239 00:14:42,820 --> 00:14:46,020 Others may use liquid hydrogen and liquid oxygen. 240 00:14:46,020 --> 00:14:48,420 Each option offers advantages. 241 00:14:48,420 --> 00:14:50,420 Why so much interest in engines? 242 00:14:50,420 --> 00:14:54,980 The type and performance of the main engines have a major influence on the whole spacecraft. 243 00:14:54,980 --> 00:15:00,420 They influence safety, weight, maintenance, preparation time, and cost. 244 00:15:00,420 --> 00:15:03,780 So what are some of the other things we can look for in the next generation RLV? 245 00:15:03,780 --> 00:15:08,180 Well, one of the things that you might see are the reusable boosters that fly back to 246 00:15:08,180 --> 00:15:09,180 the launch site. 247 00:15:09,180 --> 00:15:10,180 A booster? 248 00:15:10,180 --> 00:15:11,180 What's that? 249 00:15:11,180 --> 00:15:14,660 A booster is the primary or first stage of a multi-stage rocket. 250 00:15:14,660 --> 00:15:18,180 Okay, that makes sense, but you said the boosters are going to fly back. 251 00:15:18,180 --> 00:15:19,700 How do they do that? 252 00:15:19,700 --> 00:15:24,020 Well, they have onboard computers for navigation, and they also have onboard computers that 253 00:15:24,020 --> 00:15:28,220 work sort of like your nervous system, alerting astronauts and people on the ground whenever 254 00:15:28,220 --> 00:15:29,700 there's any kind of problem. 255 00:15:29,700 --> 00:15:31,100 Right, that's really important. 256 00:15:31,100 --> 00:15:35,020 Now, besides the onboard computer systems, how else are you going to improve safety? 257 00:15:35,020 --> 00:15:40,620 Well, when a spacecraft goes from space to our atmosphere, friction with the air can 258 00:15:40,620 --> 00:15:44,980 heat up the outside of the vehicle to temperatures over 1600 degrees centigrade. 259 00:15:44,980 --> 00:15:47,020 That's hot enough to melt steel. 260 00:15:47,020 --> 00:15:50,540 The part of the vehicle that protects the crew is called the thermal protection system, 261 00:15:50,540 --> 00:15:52,000 or TPS. 262 00:15:52,000 --> 00:15:55,420 So what is the thermal protection system made of, and how does it work? 263 00:15:55,420 --> 00:15:59,660 Currently, we are looking at a number of materials, but all thermal protection systems work with 264 00:15:59,660 --> 00:16:01,340 two basic ways. 265 00:16:01,340 --> 00:16:03,300 The first way is absorption. 266 00:16:03,300 --> 00:16:07,020 Like a potholder, you design the skin of the spacecraft so that it can absorb the heat 267 00:16:07,020 --> 00:16:09,620 of re-entry without damaging the vehicle. 268 00:16:09,620 --> 00:16:11,660 The second way is radiation. 269 00:16:11,660 --> 00:16:15,380 The outside of the vehicle is designed to radiate the heat from re-entry like a fireman's 270 00:16:15,380 --> 00:16:17,700 coat protects him from a fire. 271 00:16:17,700 --> 00:16:21,540 Some designs will combine both of these approaches to protect the astronauts and spacecraft from 272 00:16:21,540 --> 00:16:23,260 the heat of re-entry. 273 00:16:23,260 --> 00:16:27,540 The TPS has to be thin and light, but still strong enough to do the job over and over 274 00:16:27,540 --> 00:16:28,540 again. 275 00:16:28,540 --> 00:16:29,540 Kathy, that sounds difficult. 276 00:16:29,540 --> 00:16:34,620 Well, it is challenging, but remember, crew safety, it's our number one concern. 277 00:16:34,620 --> 00:16:38,740 For the next generation spacecraft system, we'll have other changes, too. 278 00:16:38,740 --> 00:16:39,740 What sort of changes? 279 00:16:39,740 --> 00:16:44,220 Well, for instance, the space shuttle carries both cargo and astronauts. 280 00:16:44,220 --> 00:16:47,740 For the next generation RLV, we want to divide those jobs. 281 00:16:47,740 --> 00:16:52,980 We are looking at two vehicles, a cargo ship with no crew on board and a smaller crew transport 282 00:16:52,980 --> 00:16:54,380 vehicle. 283 00:16:54,380 --> 00:16:59,020 Carrying the crew is much easier when they are not part of a huge cargo vehicle. 284 00:16:59,020 --> 00:17:02,980 The crew transport vehicle has a rocket engine to help it get away from the launch vehicle 285 00:17:02,980 --> 00:17:04,980 in case of any problems. 286 00:17:04,980 --> 00:17:09,360 The cargo vehicle doesn't need all the equipment required to protect people, so it can carry 287 00:17:09,360 --> 00:17:10,740 more cargo. 288 00:17:10,740 --> 00:17:12,660 It's really a win-win situation. 289 00:17:12,660 --> 00:17:13,660 That's super, Kathy. 290 00:17:13,660 --> 00:17:16,740 Thank you so much for all the information on the Space Launch Initiative. 291 00:17:16,740 --> 00:17:20,860 Now, before we move on, it's time for a cue card review. 292 00:17:20,860 --> 00:17:24,780 If you're watching the show on videotape, pause the tape now and discuss these questions. 293 00:17:24,780 --> 00:17:28,220 What is a reusable launch vehicle, or RLV? 294 00:17:28,220 --> 00:17:31,580 Why do spacecraft need to be lightweight? 295 00:17:31,580 --> 00:17:35,380 How is the RLV protected during re-entry? 296 00:17:35,380 --> 00:17:39,380 Now it's time for our viewers to get some hands-on experience building rockets. 297 00:17:39,380 --> 00:17:50,380 Hi, we're the students at Williams Technology Middle School here in Luntzville, Alabama. 298 00:17:50,900 --> 00:17:55,660 NASA Connect asked us to show you this program's hands-on activity. 299 00:17:55,660 --> 00:18:01,100 You can download the Educator Guide and a list of materials from the NASA Connect website. 300 00:18:01,100 --> 00:18:03,300 Here are the main objectives. 301 00:18:03,300 --> 00:18:09,540 Students will gather statistical data, find the optimum ratio for best vehicle performance, 302 00:18:09,540 --> 00:18:14,300 explore mathematical problem-solving, and explore mathematical models through graphing. 303 00:18:14,300 --> 00:18:16,740 Here are some terms you need to know. 304 00:18:16,740 --> 00:18:20,100 Propulsion is the act of driving forward or away. 305 00:18:20,100 --> 00:18:25,980 Thrust is a force produced by a rocket engine in reaction to a high-velocity exhaust gas. 306 00:18:25,980 --> 00:18:28,740 Kinetic energy is energy in motion. 307 00:18:28,740 --> 00:18:33,540 And momentum is a directional measurement of an object's motion, its tendency to continue 308 00:18:33,540 --> 00:18:36,420 moving in a particular direction. 309 00:18:36,420 --> 00:18:37,420 Good morning, class. 310 00:18:37,420 --> 00:18:38,980 Good morning, Ms. Smith. 311 00:18:38,980 --> 00:18:43,380 Today NASA has asked us to gather statistical data so that we can determine the optimum 312 00:18:43,380 --> 00:18:46,580 ratio of our VSV rocket. 313 00:18:46,580 --> 00:18:51,100 Groups were organized into groups of four, with each student taking on one of four jobs 314 00:18:51,100 --> 00:18:56,340 as Pre-Launch Officer, Launch Officer, Data Recorder, and Measurement Technician. 315 00:18:56,340 --> 00:18:59,420 Roles can be rotated after every trial. 316 00:18:59,420 --> 00:19:03,940 Each group will construct the launch facility by placing 20 meters of masking tape on the 317 00:19:03,940 --> 00:19:05,740 ground in a straight line. 318 00:19:05,740 --> 00:19:09,780 Divide the length of masking tape into 10-centimeter intervals. 319 00:19:09,780 --> 00:19:12,340 Place the shoebox at one end of the masking tape. 320 00:19:12,340 --> 00:19:15,140 The rocket will be placed against it each time. 321 00:19:15,140 --> 00:19:19,620 It may be necessary for the Pre-Launch Officer in the group to place gravel or dirt inside 322 00:19:19,620 --> 00:19:21,580 the box to stabilize it. 323 00:19:21,580 --> 00:19:26,940 Begin testing by using a pushpin to attach a 2-centimeter baking soda packet to the bottom 324 00:19:26,940 --> 00:19:28,020 of the cork. 325 00:19:28,020 --> 00:19:32,700 The directions to assemble the baking soda packet can be found in the Educator Guide. 326 00:19:32,700 --> 00:19:38,060 Remember, each rocket must be filled with 115 milliliters of vinegar. 327 00:19:38,060 --> 00:19:39,860 Try not to get vinegar all over yourself. 328 00:19:39,860 --> 00:19:46,340 Slide the cork with the baking soda packet attached into the neck of the bottle firmly. 329 00:19:46,340 --> 00:19:50,540 The Launch Officer will rapidly shake the rocket three times to start the reaction of 330 00:19:50,540 --> 00:19:52,900 the baking soda and vinegar. 331 00:19:52,900 --> 00:20:00,180 Quickly place the corked end of the rocket against the shoebox and move away. 332 00:20:00,180 --> 00:20:04,180 The Measurement Technician will call out the distance traveled by the rocket, and the Data 333 00:20:04,180 --> 00:20:07,880 Recorder will write the distance on the distance data chart. 334 00:20:07,880 --> 00:20:11,600 The Pre-Launch Officer will then prepare the rocket for the next trial. 335 00:20:11,600 --> 00:20:14,440 Repeat until all trials have been completed. 336 00:20:14,440 --> 00:20:19,280 Each group will plot the data onto a graph using a different color for each group. 337 00:20:19,280 --> 00:20:23,080 Students will compare the group's average data and analyze the shape of the graph to 338 00:20:23,080 --> 00:20:26,640 determine the best ratio of baking soda to vinegar. 339 00:20:26,640 --> 00:20:32,360 All right class, in comparing the data, at what point did the recorded data start increasing? 340 00:20:32,360 --> 00:20:33,360 Erica? 341 00:20:33,360 --> 00:20:36,600 It started increasing immediately. 342 00:20:36,640 --> 00:20:41,880 Why would it be important for us to find the optimum amount of fuel to use for any rocket? 343 00:20:41,880 --> 00:20:42,880 Erin? 344 00:20:42,880 --> 00:20:46,080 Because you don't want to carry more or less than you need. 345 00:20:46,080 --> 00:20:50,160 Teachers, if you would like help with the baking soda rocket lesson, simply enlist the 346 00:20:50,160 --> 00:20:55,360 help of your AIAA mentor, who will be glad to help your class with these activities. 347 00:20:55,360 --> 00:21:00,200 AIAA stands for American Institute of Aeronautics and Astronautics. 348 00:21:00,200 --> 00:21:03,200 Boy, those kids looked like they were having fun. 349 00:21:03,720 --> 00:21:08,480 No, Jennifer, I did not say having a blast, but I wanted to. 350 00:21:11,200 --> 00:21:15,640 The folks at NASA Marshall have an awesome program for next generation explorers to get 351 00:21:15,640 --> 00:21:17,960 a real feel for rocket science. 352 00:21:17,960 --> 00:21:23,080 It's called the Student Launch Initiative, SLI, just like the Space Launch Initiative. 353 00:21:23,080 --> 00:21:31,640 Initiative is the key word because these students design, build, test, launch, and reuse a rocket 354 00:21:31,640 --> 00:21:35,120 carrying a half-pound experiment. 355 00:21:35,120 --> 00:21:39,960 They experience the thrill of seeing their rockets take off and soar from one and a half 356 00:21:39,960 --> 00:21:43,760 to over three kilometers high. 357 00:21:43,760 --> 00:21:48,320 Students from Huntsville-area high schools and universities participated in NASA's first 358 00:21:48,320 --> 00:21:50,600 Student Launch Initiative. 359 00:21:50,600 --> 00:21:55,360 The students used math, science, and technology to design and build their rockets, to develop 360 00:21:55,360 --> 00:21:59,040 websites, and to apply budgeting and planning principles. 361 00:21:59,040 --> 00:22:04,720 Five, four, three, two, one. 362 00:22:04,720 --> 00:22:06,720 Igniter. 363 00:22:06,720 --> 00:22:08,720 Woo-hoo! 364 00:22:08,720 --> 00:22:10,720 Woo-hoo! 365 00:22:10,720 --> 00:22:12,720 Woo-hoo! 366 00:22:12,720 --> 00:22:14,720 Woo-hoo! 367 00:22:14,720 --> 00:22:16,720 Woo-hoo! 368 00:22:16,720 --> 00:22:20,720 Wow, Jennifer, I really want to be part of one of these SLI teams. 369 00:22:20,720 --> 00:22:24,720 Speaking of teams, where are your teammates? 370 00:22:24,720 --> 00:22:26,720 Jennifer? 371 00:22:26,720 --> 00:22:28,720 Norbert? 372 00:22:29,400 --> 00:22:31,400 Yeah! 373 00:22:31,400 --> 00:22:33,400 What is a computer simulation? 374 00:22:33,400 --> 00:22:37,400 How are computer simulations used to design spacecraft? 375 00:22:37,400 --> 00:22:42,400 How are math and science used to plan for the next generation ROV? 376 00:22:42,400 --> 00:22:48,400 The team and I are at the Collaborative Engineering Center, or CEC, here at NASA Marshall. 377 00:22:48,400 --> 00:22:54,400 The CEC is a facility that enables scientists and engineers from across the country to study 378 00:22:55,080 --> 00:23:01,080 spacecraft architecture in a virtual environment, kind of like a chat room, before they build 379 00:23:01,080 --> 00:23:02,080 the vehicles. 380 00:23:02,080 --> 00:23:04,080 They do this by using computer simulations. 381 00:23:04,080 --> 00:23:09,080 Kathy, if I remember correctly, a computer simulation is a powerful tool that allows 382 00:23:09,080 --> 00:23:13,080 engineers, such as yourself, to input data into a program. 383 00:23:13,080 --> 00:23:14,080 Exactly. 384 00:23:14,080 --> 00:23:19,080 We get to play, or I mean study, what ifs with different types of engines, structures, 385 00:23:19,080 --> 00:23:23,080 thermal protection, and whatever we want to test just by changing the data. 386 00:23:23,080 --> 00:23:24,080 That's great. 387 00:23:24,760 --> 00:23:26,760 What do you have the kids working on today? 388 00:23:26,760 --> 00:23:30,760 Earlier, we talked about how different fuel choices, which propel the spacecraft, affect 389 00:23:30,760 --> 00:23:32,760 the launch weight of the vehicle. 390 00:23:32,760 --> 00:23:36,760 By using computer simulations, we can get a real-time idea of how these choices affect 391 00:23:36,760 --> 00:23:38,760 the whole architecture. 392 00:23:38,760 --> 00:23:42,760 The computer simulation shows how one change can ripple through the entire system, like 393 00:23:42,760 --> 00:23:44,760 waves on a pond. 394 00:23:44,760 --> 00:23:45,760 I get it. 395 00:23:45,760 --> 00:23:50,760 Computer simulations allow designers to see how one choice can affect the big picture. 396 00:23:51,440 --> 00:23:55,440 Listen, another reason why simulations are so useful is because we have over 20 years 397 00:23:55,440 --> 00:23:57,440 of experience with the space shuttle. 398 00:23:57,440 --> 00:23:58,440 I see. 399 00:23:58,440 --> 00:24:03,440 So by looking at similar numbers and costs from the shuttle program, you have a starting 400 00:24:03,440 --> 00:24:05,440 off point to begin testing new ideas. 401 00:24:05,440 --> 00:24:06,440 Well, yes. 402 00:24:06,440 --> 00:24:11,440 Sometimes, of course, we have to use, engineers have to use their estimating skills to come 403 00:24:11,440 --> 00:24:13,440 up with a starting point for their calculations. 404 00:24:13,440 --> 00:24:15,440 Oh, well, can you give me an example? 405 00:24:15,440 --> 00:24:16,440 Sure. 406 00:24:16,440 --> 00:24:19,440 Suppose you are looking at TPS, thermal protection systems. 407 00:24:20,120 --> 00:24:25,120 Let's say that a low-maintenance TPS system weighs 3,000 kilograms, and the total weight 408 00:24:25,120 --> 00:24:27,120 of the vehicle is 75,000 kilograms. 409 00:24:27,120 --> 00:24:31,120 How would you estimate the thermal protection system weight to the vehicle weight ratio? 410 00:24:31,120 --> 00:24:33,120 Okay, let's see. 411 00:24:33,120 --> 00:24:40,120 3,000 kilograms TPS weight to 75,000 kilograms of vehicle weight. 412 00:24:40,120 --> 00:24:44,120 If I simplify and reduce, it's about 1 to 25. 413 00:24:44,120 --> 00:24:45,120 Exactly. 414 00:24:45,120 --> 00:24:49,120 We might find that one system is heavier, but the reduced maintenance costs might still 415 00:24:49,800 --> 00:24:50,800 be a good idea. 416 00:24:50,800 --> 00:24:53,800 Of course, eventually, you have to build and test systems and hardware, but think of the 417 00:24:53,800 --> 00:24:56,800 time and money you save testing with the simulations first. 418 00:24:56,800 --> 00:24:58,800 And it allows more creativity. 419 00:24:58,800 --> 00:24:59,800 Absolutely. 420 00:24:59,800 --> 00:25:02,800 See how they're trying different thermal protection systems? 421 00:25:02,800 --> 00:25:05,800 Look what it does to the vehicle weight and structure, too. 422 00:25:05,800 --> 00:25:08,800 What did we do before we had all this technology? 423 00:25:08,800 --> 00:25:11,800 Well, for one thing, we did calculations by hand. 424 00:25:11,800 --> 00:25:14,800 We also built and tested a whole lot more hardware. 425 00:25:15,480 --> 00:25:20,480 Of course, that was okay then, but now engineers have so many more tools to help them, but 426 00:25:20,480 --> 00:25:23,480 they still must use math, science, and technology. 427 00:25:23,480 --> 00:25:27,480 First, there has to be computer scientists and mathematicians to design the software 428 00:25:27,480 --> 00:25:30,480 and hardware that is needed for computer simulations. 429 00:25:30,480 --> 00:25:35,480 Remember, the computer only calculates the data, but the engineers need sharp math and 430 00:25:35,480 --> 00:25:39,480 science skills to analyze the results and decide on the final design. 431 00:25:39,480 --> 00:25:44,480 The Space Launch Initiative will get a spacecraft to orbit more safely and less expensively. 432 00:25:45,160 --> 00:25:49,160 That's going to take a team effort, and it's not too early for your next generation 433 00:25:49,160 --> 00:25:51,160 explorers to start getting ready. 434 00:25:51,160 --> 00:25:53,160 Doing well in school is the most important step. 435 00:25:53,160 --> 00:25:55,160 I couldn't agree with you more. 436 00:25:55,160 --> 00:25:58,160 Thank you so much, Kathy, for sharing all the information you did with us. 437 00:25:58,160 --> 00:25:59,160 Oh, no problem. 438 00:25:59,160 --> 00:26:00,160 We really appreciate it. 439 00:26:00,160 --> 00:26:03,160 The kids had a great time, and I'm sure I'm going to have a really hard time pulling them 440 00:26:03,160 --> 00:26:04,160 away from here. 441 00:26:04,160 --> 00:26:05,160 Well, thanks for coming. 442 00:26:05,160 --> 00:26:06,160 You're welcome. 443 00:26:06,160 --> 00:26:09,160 Hey, while we're here, let's do our last cue card reveal. 444 00:26:09,160 --> 00:26:11,160 What is a computer simulation? 445 00:26:11,840 --> 00:26:14,840 How are computer simulations used to design spacecraft? 446 00:26:14,840 --> 00:26:19,840 How are math and science used to plan for the next generation RLV? 447 00:26:19,840 --> 00:26:22,840 If you're watching on tape, you can pause and discuss. 448 00:26:22,840 --> 00:26:27,840 And teachers, if you would like a videotape of this program and the accompanying educator 449 00:26:27,840 --> 00:26:30,840 guide, check out the NASA Connect website. 450 00:26:30,840 --> 00:26:34,840 Well, Dan, that wraps up this episode of NASA Connect. 451 00:26:34,840 --> 00:26:40,840 So the question of the day is, are you ready to join the next generation of space explorers? 452 00:26:41,520 --> 00:26:42,520 You better believe it, Jennifer. 453 00:26:42,520 --> 00:26:45,520 We'd like to thank everyone who helped make this program possible. 454 00:26:45,520 --> 00:26:50,520 If you have comments or suggestions about this episode or about NASA Connect in general, 455 00:26:50,520 --> 00:26:55,520 email us at connect at larc dot nasa dot gov. 456 00:26:55,520 --> 00:27:01,520 Or pick up a pen and write us at NASA Connect, NASA's Center for Distance Learning, NASA 457 00:27:01,520 --> 00:27:06,520 Langley Research Center, Mail Stop 400, Hampton, Virginia, 23681. 458 00:27:07,200 --> 00:27:11,200 You can also link to NASA Corps, the NASA Central Operations of Resources for Educators. 459 00:27:11,200 --> 00:27:17,200 To view this and past shows, go to NASA Quest at quest dot nasa dot gov. 460 00:27:17,200 --> 00:27:23,200 Until next time, stay connected to math, science, technology, and NASA. 461 00:27:23,200 --> 00:27:25,200 See you again! 462 00:27:25,200 --> 00:27:26,200 Bye! 463 00:27:32,200 --> 00:27:33,200 Thanks, Jennifer. 464 00:27:33,880 --> 00:27:36,880 Today, we're visiting the Challenger Center in Chattanooga, Tennessee. 465 00:27:36,880 --> 00:27:39,880 The students of the Chattanooga, Tennessee, of... 466 00:27:39,880 --> 00:27:40,880 Chattanooga, Tennessee, huh? 467 00:27:40,880 --> 00:27:41,880 Okay, sorry. 468 00:27:43,880 --> 00:27:46,880 The amount of attraction really depends on the mass of the object. 469 00:27:46,880 --> 00:27:47,880 Mass? 470 00:27:51,880 --> 00:27:52,880 What happened? 471 00:27:54,880 --> 00:27:56,880 More force is needed to reach orbit. 472 00:27:57,880 --> 00:27:58,880 Sorry. 473 00:27:59,880 --> 00:28:00,880 In orbit. 474 00:28:00,880 --> 00:28:01,880 In orbit. 475 00:28:01,880 --> 00:28:02,880 In orbit. 476 00:28:03,560 --> 00:28:07,560 By learning how NASA is getting spacecraft into orbit less safely... 477 00:28:11,560 --> 00:28:14,560 The more force is needed to reach orbit. 478 00:28:15,560 --> 00:28:16,560 Orbit. 479 00:28:16,560 --> 00:28:17,560 Orbit. 480 00:28:17,560 --> 00:28:18,560 Orbit. 481 00:28:18,560 --> 00:28:19,560 Orbit. 482 00:28:19,560 --> 00:28:20,560 Sorry. 483 00:28:20,560 --> 00:28:21,560 It's been a long day. 484 00:28:24,560 --> 00:28:27,560 Captioning funded by the NEC Foundation of America.