1 00:00:00,000 --> 00:00:07,560 Now that you have a basic understanding of energy, let's hear about some innovative propulsion 2 00:00:07,560 --> 00:00:12,040 technologies that NASA is developing for future space exploration. 3 00:00:12,040 --> 00:00:15,440 And don't forget, you are the future explorers. 4 00:00:15,440 --> 00:00:17,200 Thanks, Jennifer. 5 00:00:17,200 --> 00:00:18,840 Space is big. 6 00:00:18,840 --> 00:00:24,240 Distances to Mars and beyond are so large that when using today's spacecraft technology, 7 00:00:24,240 --> 00:00:27,600 we can only send relatively small spacecraft. 8 00:00:27,600 --> 00:00:32,000 In other words, distance affects the mass that we can send. 9 00:00:32,000 --> 00:00:37,440 NASA is working on a new way of powering space vehicles that will enable us to send more 10 00:00:37,440 --> 00:00:44,400 complex spacecraft to Mars, Jupiter, and beyond, and may even shorten the travel time. 11 00:00:44,400 --> 00:00:47,180 The new program is called Prometheus. 12 00:00:47,180 --> 00:00:51,840 It will provide a giant leap in our ability to explore our solar system. 13 00:00:51,840 --> 00:00:57,720 The program focuses on using nuclear power in long-distance spacecraft. 14 00:00:57,720 --> 00:01:02,720 The nuclear power system will create electricity that will be used for two things. 15 00:01:02,720 --> 00:01:05,560 One job will be to propel the spacecraft. 16 00:01:05,560 --> 00:01:09,500 The other will be to provide power for the instruments on board. 17 00:01:09,500 --> 00:01:15,100 This capability will let NASA send spacecraft to places that we currently want to reach. 18 00:01:15,100 --> 00:01:21,200 It would also allow us to do more scientific work when the spacecraft reaches its destination 19 00:01:21,320 --> 00:01:25,240 and could even help speed up travel through the solar system. 20 00:01:25,240 --> 00:01:28,080 Many space missions have used nuclear power. 21 00:01:28,080 --> 00:01:33,920 The farthest known man-made object is the nuclear-powered spacecraft called Voyager 1. 22 00:01:33,920 --> 00:01:37,560 This probe has been used for over 26 years. 23 00:01:37,560 --> 00:01:40,720 It is now over 8 billion miles away. 24 00:01:40,720 --> 00:01:44,040 That's more than twice the distance from the Sun to Pluto. 25 00:01:44,040 --> 00:01:48,880 Remember, earlier in the program, Jennifer asked you to list some forms of energy? 26 00:01:48,880 --> 00:01:56,320 On my list, I have mechanical energy, thermal energy, chemical energy, electromagnetic energy, 27 00:01:56,320 --> 00:01:57,880 and nuclear energy. 28 00:01:57,880 --> 00:02:03,160 Project Prometheus will be using nuclear energy to help power the spacecraft. 29 00:02:03,160 --> 00:02:06,680 Nuclear energy is the energy stored in the nucleus of an atom. 30 00:02:06,680 --> 00:02:12,760 In a nuclear reaction, a tiny portion of an atom's mass is turned into energy. 31 00:02:12,760 --> 00:02:17,080 Scientists are studying two different ways of using the energy stored within the nucleus 32 00:02:17,080 --> 00:02:18,520 of an atom. 33 00:02:18,520 --> 00:02:23,720 The first approach is to take an atom that is naturally very unstable, which means that 34 00:02:23,720 --> 00:02:27,840 the atom wants to change into a different, more stable atom. 35 00:02:27,840 --> 00:02:34,040 During this change, the atom releases tiny particles causing the material to heat up. 36 00:02:34,040 --> 00:02:37,000 This process is known as radioactive decay. 37 00:02:37,000 --> 00:02:40,520 The released particles are called radiation. 38 00:02:40,520 --> 00:02:45,240 The heat that is released can be harnessed and converted to electrical energy. 39 00:02:45,240 --> 00:02:49,080 This energy can then be used to power the spacecraft systems. 40 00:02:49,080 --> 00:02:52,040 It is called radioisotope decay. 41 00:02:52,040 --> 00:02:57,240 The second approach is to break apart the nucleus of the atom to release even more energy 42 00:02:57,240 --> 00:02:59,360 than radioactive decay. 43 00:02:59,360 --> 00:03:02,240 This process is called nuclear fission. 44 00:03:02,240 --> 00:03:07,440 It is used in nuclear power plants all around the world to produce electricity. 45 00:03:07,440 --> 00:03:11,280 Nuclear fission systems can generate large amounts of power. 46 00:03:11,280 --> 00:03:13,000 Think of this comparison. 47 00:03:13,040 --> 00:03:18,480 A radioisotope power system could create enough power to light a few light bulbs. 48 00:03:18,480 --> 00:03:24,080 A nuclear fission power system could create enough energy to power a laundromat. 49 00:03:24,080 --> 00:03:29,360 This increased amount of energy means that a nuclear fission energy system could do more 50 00:03:29,360 --> 00:03:33,000 than just power a spacecraft's scientific instruments. 51 00:03:33,000 --> 00:03:37,080 It could also be used to run the engines that propel the rocket. 52 00:03:37,080 --> 00:03:39,760 NASA hopes to use this technology soon. 53 00:03:39,760 --> 00:03:44,040 In fact, it's already working on the first probe to use this technology. 54 00:03:44,040 --> 00:03:46,720 This probe is the Prometheus 1 mission. 55 00:03:46,720 --> 00:03:50,360 This mission will use a nuclear fission system. 56 00:03:50,360 --> 00:03:56,040 This system would provide energy for both spacecraft electrical power and propulsion. 57 00:03:56,040 --> 00:04:03,320 Prometheus 1 would orbit three of the larger moons of Jupiter, Callisto, Ganymede and Europa. 58 00:04:03,320 --> 00:04:08,080 Europa is one of our solar system's most fascinating celestial bodies. 59 00:04:08,080 --> 00:04:13,200 Europa's surface is completely covered in ice, but scientists believe that the solar 60 00:04:13,200 --> 00:04:17,120 system's largest oceans could be hidden under that ice. 61 00:04:17,120 --> 00:04:22,720 If oceans are indeed present, there is a possibility that life could be found there. 62 00:04:22,720 --> 00:04:27,880 The Prometheus 1 mission will be finding answers to the mysteries of these moons. 63 00:04:27,880 --> 00:04:33,320 One day, the same power and propulsion systems used on Prometheus 1 could be used to send 64 00:04:33,320 --> 00:04:36,360 probes to other far-off places. 65 00:04:36,360 --> 00:04:40,680 These systems will even be used to support human missions to explore the solar system 66 00:04:40,680 --> 00:04:41,680 and beyond. 67 00:04:41,680 --> 00:04:42,800 Back to you, Jennifer.