WEBVTT FILE 1 00:00:00.433 --> 00:00:05.633 [Music] 2 00:00:05.633 --> 00:00:07.966 The Lucy spacecraft will be taking a journey 3 00:00:07.966 --> 00:00:12.533 where no other spacecraft has gone before: The Trojan asteroids. 4 00:00:12.533 --> 00:00:15.533 The Trojans are two groups of asteroids that lead and trail Jupiter 5 00:00:15.533 --> 00:00:17.500 in its orbit around the sun – 6 00:00:17.500 --> 00:00:19.333 and they’ve been trapped in these stable locations 7 00:00:19.333 --> 00:00:22.400 for over four billion years. 8 00:00:22.400 --> 00:00:25.600 Lucy will have a suite of scientific instruments for collecting data 9 00:00:25.600 --> 00:00:28.466 as it flies by the asteroids. 10 00:00:28.466 --> 00:00:31.266 L’LORRI is a long range reconnaissance imager. 11 00:00:31.266 --> 00:00:33.666 It’s often referred to as Lucy’s eagle eyes 12 00:00:33.666 --> 00:00:38.133 since it has the highest spatial resolution of all of Lucy’s cameras. 13 00:00:38.133 --> 00:00:41.400 This black-and-white camera is actually a type of telescope, 14 00:00:41.400 --> 00:00:44.500 the same kind as the Hubble Space Telescope. 15 00:00:44.500 --> 00:00:48.200 L’LORRI was built to produce clear images of the Trojans’ craters, 16 00:00:48.200 --> 00:00:50.433 which will be a challenge since the Trojan asteroids 17 00:00:50.433 --> 00:00:53.733 are extremely dark. 18 00:00:53.733 --> 00:00:56.866 L’LORRI will be able to see 75-yard-wide craters 19 00:00:56.866 --> 00:00:59.033 from over 600 miles away. 20 00:00:59.033 --> 00:01:01.366 That’s like standing at one end of a football field 21 00:01:01.366 --> 00:01:04.366 and being able to see a fly at the other end! 22 00:01:04.366 --> 00:01:07.466 The instrument’s simple design does not use optical filters 23 00:01:07.466 --> 00:01:09.333 and includes no moving parts, 24 00:01:09.333 --> 00:01:13.300 reducing the risk of part failure during the mission. 25 00:01:13.300 --> 00:01:16.600 L’LORRI will also search the Trojans for evidence of any rings 26 00:01:16.600 --> 00:01:18.533 and new satellites. 27 00:01:18.533 --> 00:01:21.600 The instrument's ability to see faint targets from far away 28 00:01:21.600 --> 00:01:25.200 also makes it perfect for optical navigation. 29 00:01:25.200 --> 00:01:28.133 L’LORRI will help Lucy navigate to a point in space, 30 00:01:28.133 --> 00:01:30.966 and then a terminal tracking camera aboard the spacecraft, 31 00:01:30.966 --> 00:01:33.333 known as T2Cam, will help the instruments 32 00:01:33.333 --> 00:01:36.300 accurately point toward the targets. 33 00:01:36.966 --> 00:01:39.800 L’TES is Lucy’s thermal emission spectrometer 34 00:01:39.800 --> 00:01:43.433 which detects far infrared radiation emitted by the asteroids 35 00:01:43.433 --> 00:01:45.633 due to how they are heated up by sunlight. 36 00:01:46.466 --> 00:01:49.300 L’TES detects this radiation using a small telescope 37 00:01:49.300 --> 00:01:52.266 to focus the incoming energy onto a detector – 38 00:01:52.266 --> 00:01:56.333 similar to the way a remote thermometer works. 39 00:01:56.333 --> 00:01:59.466 So, L’TES is not taking images, but rather, 40 00:01:59.466 --> 00:02:03.400 temperature measurements at various points on the asteroid. 41 00:02:03.400 --> 00:02:05.866 This data will be combined so that scientists can get an 42 00:02:05.866 --> 00:02:07.833 understanding of its surface properties. 43 00:02:09.466 --> 00:02:12.433 L’TES will examine the properties of the regolith on the surface 44 00:02:12.433 --> 00:02:15.766 by measuring thermal inertia, which is the measure of how slowly 45 00:02:15.766 --> 00:02:19.766 the asteroid heats up from sunlight and then releases that heat. 46 00:02:19.766 --> 00:02:21.166 By taking the temperature readings 47 00:02:21.166 --> 00:02:23.100 at different parts of the asteroid, 48 00:02:23.100 --> 00:02:25.900 the Lucy science team can measure the thermal inertia 49 00:02:25.900 --> 00:02:28.533 and figure out how much dust, sand or rock 50 00:02:28.533 --> 00:02:31.133 is present on the asteroid’s surface. 51 00:02:31.133 --> 00:02:34.333 That data will tell us a lot about how the asteroid was formed, 52 00:02:34.333 --> 00:02:37.633 providing insight into the history of our solar system. 53 00:02:39.266 --> 00:02:41.833 Lucy’s L’Ralph instrument will search the Trojans 54 00:02:41.833 --> 00:02:45.433 for organics, ices, and hydrated minerals, and will help determine 55 00:02:45.433 --> 00:02:48.133 the surface compositions of the asteroids. 56 00:02:48.133 --> 00:02:50.600 L’Ralph is actually two instruments in one 57 00:02:50.600 --> 00:02:52.400 and together they will measure and analyze 58 00:02:52.400 --> 00:02:56.000 the spectra of light absorbed and reflected by the asteroid. 59 00:02:56.000 --> 00:02:58.266 The first is a color visible imager - 60 00:02:58.266 --> 00:03:01.633 the Multi-spectral Visible Imaging Camera or MVIC. 61 00:03:01.633 --> 00:03:05.000 It takes visible light color images of the Trojan asteroids. 62 00:03:05.000 --> 00:03:08.666 The second is an infrared imaging spectrometer known as LEISA - 63 00:03:08.666 --> 00:03:11.266 the Linear Etalon Imaging Spectral Array - 64 00:03:11.266 --> 00:03:15.400 which collects infrared spectra of the asteroids. 65 00:03:15.400 --> 00:03:19.033 Like L’LORRI, L’Ralph does not have a focusing mechanism. 66 00:03:19.033 --> 00:03:21.466 Instead, it is designed to stay in focus 67 00:03:21.466 --> 00:03:24.466 despite the extreme temperature differences in space 68 00:03:24.466 --> 00:03:28.466 by being made almost entirely from a single block of aluminum. 69 00:03:28.466 --> 00:03:30.700 Using one material throughout the instrument means that 70 00:03:30.700 --> 00:03:32.700 if a part expands or contracts, 71 00:03:32.700 --> 00:03:35.433 the other parts will expand or contract at the same rate, 72 00:03:35.433 --> 00:03:38.033 helping to keep L’Ralph in focus. 73 00:03:38.033 --> 00:03:39.866 Even the mirrors are made of aluminum 74 00:03:39.866 --> 00:03:42.266 finely polished with diamond dust. 75 00:03:42.266 --> 00:03:45.466 Due to the massive size of the images L’Ralph will be taking, 76 00:03:45.466 --> 00:03:49.600 the instrument will have around 256 gigabits of onboard memory. 77 00:03:49.600 --> 00:03:52.200 And while the L’Ralph instrument aboard Lucy does require 78 00:03:52.200 --> 00:03:55.866 substantially more power than its predecessors on other spacecraft, 79 00:03:55.866 --> 00:03:59.366 it still will not use more energy than your average ceiling fan. 80 00:04:01.133 --> 00:04:03.866 In addition to these three main science instruments, 81 00:04:03.866 --> 00:04:07.900 other experiments aboard the spacecraft will help fulfill the mission. 82 00:04:07.900 --> 00:04:11.066 Lucy will use its High Gain Antenna to communicate with Earth 83 00:04:11.066 --> 00:04:13.500 for an additional radio science experiment 84 00:04:13.500 --> 00:04:16.466 to determine the masses of the asteroid targets. 85 00:04:16.466 --> 00:04:19.933 Lucy will also be able to use its two terminal tracking cameras, 86 00:04:19.933 --> 00:04:23.433 or T2CAM, to track the asteroids during the flybys, 87 00:04:23.433 --> 00:04:26.666 keep them in the field of view, and to take wide-field images 88 00:04:26.666 --> 00:04:28.766 so that we can better determine their shapes, 89 00:04:28.766 --> 00:04:31.766 and perhaps discover new asteroids nearby. 90 00:04:33.533 --> 00:04:36.866 As you can see, the Lucy spacecraft has a large suite of tools 91 00:04:36.866 --> 00:04:39.966 to study the Trojan asteroids, which will help us better understand 92 00:04:39.966 --> 00:04:42.966 the formation of our solar system.