English subtitles for clip: File:0491 Moon Travel 01 30 24 00.webm
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1 00:00:19,19 --> 00:00:22,86 What would it be like to be on the moon a question 2 00:00:22,86 --> 00:00:28,08 that has intrigued men since long before the invention of the telescope to travel 3 00:00:28,08 --> 00:00:32,41 across the roughly marked surface of our nearest neighbor in space is an experience 4 00:00:32,41 --> 00:00:37,79 that man will soon be having probably before this decade is over the first 5 00:00:37,79 --> 00:00:40,33 explorers from Earth will have arrived on the moon 6 00:00:41,49 --> 00:00:46,87 but how will they explore a planet without roads without atmosphere with gravity 7 00:00:46,87 --> 00:00:51,30 only one sixth that of Earth. 8 00:00:51,32 --> 00:00:55,49 Scientists are studying answers to these questions. 9 00:00:55,51 --> 00:00:57,94 First by gathering information on the conditions 10 00:00:57,94 --> 00:00:59,80 that will likely be found on the moon. 11 00:01:00,30 --> 00:01:05,53 Then by developing new concepts of travel for vehicles such as we have never seen 12 00:01:05,53 --> 00:01:07,63 on earth to cross terrain 13 00:01:07,63 --> 00:01:14,42 that is unique to the moon the research starts in a 14 00:01:14,42 --> 00:01:19,63 laboratory here the vacuum conditions found on the moon are studied for the effect 15 00:01:19,63 --> 00:01:22,14 they will have on lunar soil. 16 00:01:22,15 --> 00:01:28,70 The large bell jar has been pumped down to a very high vacuum inside as a device 17 00:01:28,70 --> 00:01:34,33 that is designed to measure the strength of soil at its base there are two discs of 18 00:01:34,33 --> 00:01:34,76 different sizes 19 00:01:35,71 --> 00:01:40,18 and an annular ribbon the disks are pushed straight down into the soil 20 00:01:41,02 --> 00:01:45,22 and both the vertical force applied and the penetration are measured. 21 00:01:46,10 --> 00:01:50,68 This tells something about how much weight the soil will be able to bear in this 22 00:01:50,68 --> 00:01:56,49 case the soil used as pumice which is believed to be similar to certain lunar soils. 23 00:01:57,67 --> 00:01:59,87 A second test involves the annular rain. 24 00:02:00,00 --> 00:02:04,45 Or shearing as it's called a known load is applied at the top 25 00:02:04,45 --> 00:02:08,46 and then the ring is twisted the horizontal force being developed 26 00:02:08,46 --> 00:02:11,09 and the angle of rotation are both measured. 27 00:02:11,23 --> 00:02:18,12 This tells us something about the amount of traction vehicle can develop here 28 00:02:18,13 --> 00:02:23,43 the same test is shown being applied to a gravel soil under similar conditions. 29 00:02:26,43 --> 00:02:28,04 Another effect which is studied is 30 00:02:28,04 --> 00:02:33,47 that of low gravity air being tested on a free falling device known as an Atwood 31 00:02:33,47 --> 00:02:38,80 type machine. It reveals what happens to a soil in gravity only one sixth 32 00:02:38,80 --> 00:02:45,43 that of Earth where one hundred pounds weighs only sixteen arrow soil 33 00:02:45,43 --> 00:02:47,90 test disk is shown being attached to a release 34 00:02:48,92 --> 00:02:53,60 when the test is actually run this disc will be released into a capsule of soil 35 00:02:53,60 --> 00:02:59,65 which is falling at an acceleration which simulates the lunar gravity. 36 00:03:03,52 --> 00:03:09,29 The entire device is raised high into the air then dropped during the drop though 37 00:03:09,29 --> 00:03:13,29 so rapidly it could not be seen the soil test disc is released 38 00:03:13,29 --> 00:03:19,53 and the effect of low gravity on soil is measured. 39 00:03:22,30 --> 00:03:27,29 Based on such tests of soil properties several vehicle models designed for Moon 40 00:03:27,29 --> 00:03:32,17 travel were developed here is a vehicle based on the Archimedean screw principle 41 00:03:32,17 --> 00:03:38,69 propelled by the turning of four large screws this wheeled vehicle rolls on 42 00:03:38,69 --> 00:03:42,48 six large soft tires arranged on three axles 43 00:03:48,96 --> 00:03:54,55 and this track type vehicle is composed of two units with wrap around tracks. 44 00:03:58,66 --> 00:03:59,89 These vehicles were tested. 45 00:04:00,00 --> 00:04:04,23 In a soil bin containing soils of a type likely to be encountered on the lunar 46 00:04:04,23 --> 00:04:09,64 surface here the track vehicle is made to crawl over simulated Doom's of fine 47 00:04:09,64 --> 00:04:10,08 pumice. 48 00:04:11,45 --> 00:04:16,45 The wrap around tracks are elastic with flexible prongs to conform to the terrain 49 00:04:17,17 --> 00:04:22,10 while staring at the pivot between the units. 50 00:04:22,12 --> 00:04:26,35 The Archimedean screw vehicle is designed to operate only where the soil is so soft 51 00:04:27,17 --> 00:04:31,49 that it cannot support the weight of a vehicle and it burrows through the soil. 52 00:04:32,59 --> 00:04:37,27 It is steered by running the various crew elements at different speeds managing 53 00:04:37,27 --> 00:04:41,46 slow but effective turns. 54 00:04:42,17 --> 00:04:46,24 The electric cord trailing behind it is used to deliver power to the model. 55 00:04:47,05 --> 00:04:52,23 It is not intended for actual moon vehicles which will use batteries or fuel cells. 56 00:04:53,55 --> 00:04:55,64 Generally this group principle is not very efficient. 57 00:04:56,28 --> 00:05:13,21 And would be used only for special applications such as this exceedingly soft soil. 58 00:05:14,30 --> 00:05:16,88 The wheeled vehicle is mechanically the most efficient 59 00:05:16,88 --> 00:05:19,14 and reliable of the three designs. 60 00:05:19,44 --> 00:05:25,08 While it cannot perform as well as a track on soft ground its many other advantages 61 00:05:25,08 --> 00:05:32,11 make it an attractive solution to the problem of an all around moon vehicle. 62 00:05:33,05 --> 00:05:35,37 This particular model has three axles 63 00:05:35,37 --> 00:05:41,27 or units individually driven by three separate electric motors the axles are 64 00:05:41,27 --> 00:05:45,60 connected to each other by elastic rods which enable the units to dip 65 00:05:45,60 --> 00:05:47,70 and roll with respect to one another. 66 00:05:48,86 --> 00:05:52,89 Steering is accomplished by the small steering Motors mounted on the front 67 00:05:52,89 --> 00:05:57,70 and rear units. But wheel shown on this model are made of foam rubber. 68 00:05:57,91 --> 00:05:59,93 But this would not be the case for a. 69 00:06:00,00 --> 00:06:04,81 Moon vehicle since foam rubber could never endure the severe lunar temperatures 70 00:06:05,58 --> 00:06:11,18 instead of size design might feature lightweight wire frames which would be covered 71 00:06:11,18 --> 00:06:15,22 with a thin top plastic material. 72 00:06:15,24 --> 00:06:18,76 In case the lunar surface does not turn out to be a fine dust. 73 00:06:19,29 --> 00:06:21,71 But instead consists of a rough and rocky terrain 74 00:06:22,76 --> 00:06:25,93 that wheeled vehicle will perhaps show itself to its best advantage. 75 00:06:27,34 --> 00:06:31,31 The individually powered units have good obstacle climbing ability even 76 00:06:31,31 --> 00:06:36,03 when the obstacles are more than twice the height of the wheels the vehicle can 77 00:06:36,03 --> 00:06:36,98 force itself over 78 00:06:36,98 --> 00:06:43,20 and around boulders yet always hug the terrain because of its special design which 79 00:06:43,20 --> 00:06:48,33 is called articulated. 80 00:06:49,59 --> 00:06:55,18 If obstacles such as chasms occur such as the space between boulders the vehicle 81 00:06:55,18 --> 00:07:01,33 will bridge the obstacle with its long body. 82 00:07:03,67 --> 00:07:05,18 Where one unit has lost traction 83 00:07:05,18 --> 00:07:10,86 and cannot pull the others will push it along in turn if they lose traction. 84 00:07:11,45 --> 00:07:14,89 They will be pulled along so that the vehicle remains in motion. 85 00:07:15,24 --> 00:07:16,05 Whatever the soil 86 00:07:16,05 --> 00:07:21,88 or terrain in general the wheeled vehicle seems a promising solution to the problem 87 00:07:21,88 --> 00:07:28,11 of Moon travel yet much work remains to be done. 88 00:07:28,43 --> 00:07:29,32 Further 89 00:07:29,32 --> 00:07:34,97 and more realistic testing in the moon environment must still be accomplished New 90 00:07:34,97 --> 00:07:39,65 Moon vehicles will be conceived designed and put through their paces so 91 00:07:39,66 --> 00:07:44,26 that the astronauts of tomorrow will have the vehicles to carry them safely to the 92 00:07:44,26 --> 00:07:45,90 farthest reaches of the moon.