WEBVTT FILE 1 00:00:00.600 --> 00:00:03.000 The laser: a useful tool 2 00:00:03.000 --> 00:00:05.766 in industry, science and medicine. 3 00:00:06.133 --> 00:00:11.200 When it comes down to it, a laser is just a light with extreme focus. 4 00:00:11.200 --> 00:00:15.366 It's both elegantly simple and extremely complicated, 5 00:00:15.366 --> 00:00:19.133 and it changed the way we literally see the dimensions of our Earth, 6 00:00:19.733 --> 00:00:24.333 our Moon, the planets, asteroids and beyond. 7 00:00:25.200 --> 00:00:27.433 But it was a long road to get there. 8 00:00:27.433 --> 00:00:32.666 [music] 9 00:00:34.133 --> 00:00:37.433 Back in the 1980s at NASA, using lasers to measure 10 00:00:37.433 --> 00:00:42.300 physical features from space was too experimental, too risky. 11 00:00:42.300 --> 00:00:45.833 Fortunately, it was also a time of change and risk- 12 00:00:45.833 --> 00:00:48.333 taking at Goddard Space Flight Center. 13 00:00:49.100 --> 00:00:50.366 In the 1960s, 14 00:00:50.366 --> 00:00:52.166 there was probably not much question 15 00:00:52.166 --> 00:00:54.200 that when a science or applications mission came up, 16 00:00:54.233 --> 00:00:57.233 for the most part, it went to Goddard 17 00:00:57.233 --> 00:01:01.000 and we've got to do a better job of selling ourselves 18 00:01:01.000 --> 00:01:05.700 and being sure that we're responsive to what Headquarters is looking for 19 00:01:05.966 --> 00:01:09.600 in terms of the competition between ourselves and other NASA centers. 20 00:01:09.600 --> 00:01:12.766 I came here as hired by the center director, 21 00:01:12.766 --> 00:01:16.000 Noel Hinners, in '85, and he said, So what do you want to do? 22 00:01:16.000 --> 00:01:19.900 I said, I want to map the topography of Mars, you know, at this scale, not 23 00:01:19.900 --> 00:01:21.400 the scale of buildings. 24 00:01:22.466 --> 00:01:23.433 How do we do that? 25 00:01:23.433 --> 00:01:25.900 He goes, Well, we've got folks. They do stuff. 26 00:01:25.900 --> 00:01:29.700 And so I met a few of them very quickly, and that was Jim Abshire, John 27 00:01:29.700 --> 00:01:31.633 Degnan, Jack Bufton. 28 00:01:31.633 --> 00:01:36.166 We started working with laser remote sensing instrumentation. 29 00:01:36.433 --> 00:01:40.366 It was the same type of instrumentation that communicated 30 00:01:40.366 --> 00:01:44.033 from ground to satellites in satellite laser ranging. 31 00:01:45.033 --> 00:01:47.933 We could do a little airborne laser remote 32 00:01:47.933 --> 00:01:52.400 sensing, and Garvin and I sort of found each other through that. 33 00:01:52.666 --> 00:01:55.966 You know, I said, Come on down to Wallops and we'll fly this. 34 00:01:55.966 --> 00:02:00.233 And he said, Oh, topography, Earth, yes, I want to measure it. 35 00:02:01.033 --> 00:02:03.900 We literally took a T-39 training aircraft that was 36 00:02:03.900 --> 00:02:07.266 put together by the Wallops team really impressively 37 00:02:08.033 --> 00:02:12.100 and bolted in a big telescope with a laser 38 00:02:12.433 --> 00:02:15.700 and went flying out in northern Arizona where I had done some field work. 39 00:02:15.933 --> 00:02:19.300 So out there we have Meteor Crater, we have volcanoes 40 00:02:19.600 --> 00:02:22.100 and we have the Grand Canyon and other the Painted Desert. 41 00:02:22.433 --> 00:02:25.200 So we figured in one place we could study all this. 42 00:02:25.966 --> 00:02:30.933 And it was on the strength of that, that Jim Garvin became interested 43 00:02:30.933 --> 00:02:35.666 and put him in a position to when Dave Smith found 44 00:02:35.666 --> 00:02:41.333 that his radar altimeter was canceled because it was $30 million instead of ten. 45 00:02:41.900 --> 00:02:43.800 They kept talking to me about, you know, 46 00:02:43.800 --> 00:02:47.100 look, we're really close to getting a laser altimeter working. 47 00:02:47.100 --> 00:02:50.866 And I've been in lasers actually for 20 odd years before that, 48 00:02:50.866 --> 00:02:52.066 if you know what I mean. 49 00:02:52.066 --> 00:02:54.100 But laser ranging from the ground to spacecraft. 50 00:02:54.100 --> 00:02:58.433 So I was very familiar with the lasers and I wasn't averse to it, on the contrary. 51 00:02:59.100 --> 00:03:02.200 But NASA offered me a situation that said, look, 52 00:03:02.200 --> 00:03:04.300 we've got a certain amount of money for you. 53 00:03:04.433 --> 00:03:06.600 We're willing to spend $10 million on this instrument. 54 00:03:07.366 --> 00:03:09.933 But, you know, there has to be some sort of competition. 55 00:03:09.933 --> 00:03:12.133 You need to choose which instrument 56 00:03:12.133 --> 00:03:14.366 you would like to fly to measure the altimetry. 57 00:03:14.700 --> 00:03:16.333 And there were four candidates. 58 00:03:17.466 --> 00:03:21.200 Three of them are radar and one the laser that we call MOLA 59 00:03:21.800 --> 00:03:24.866 There was no one in their right mind that would bid 60 00:03:24.866 --> 00:03:26.133 a laser altimeter. 61 00:03:26.133 --> 00:03:27.433 Seriously. 62 00:03:28.000 --> 00:03:28.966 And I was all gung ho. 63 00:03:28.966 --> 00:03:31.900 I was a young guy, you know, no gray hair. 64 00:03:31.900 --> 00:03:33.466 There was a lot of reticence. 65 00:03:33.466 --> 00:03:37.766 There was so little trust that this could be done. 66 00:03:38.100 --> 00:03:41.433 NASA's made a monumental achievement 67 00:03:41.433 --> 00:03:45.900 in both radar and visible near infrared 68 00:03:45.900 --> 00:03:49.100 imaging of the surfaces of Earth and other planets. 69 00:03:49.466 --> 00:03:51.700 But those are flat field views. 70 00:03:51.700 --> 00:03:52.733 And the missing dimension, 71 00:03:52.733 --> 00:03:56.400 the hidden dimension, which drives where energy goes, where the water flows, 72 00:03:57.033 --> 00:03:58.133 you know, 73 00:03:58.133 --> 00:04:00.533 stability of landscapes is the third dimension. 74 00:04:00.533 --> 00:04:01.933 We take for granted the map. 75 00:04:02.300 --> 00:04:04.966 Sometimes you need the map to do with beyond the map. 76 00:04:04.966 --> 00:04:08.000 Making those maps with that crucial third dimension is 77 00:04:08.000 --> 00:04:11.633 what laser altimetry or LiDAR is best at. 78 00:04:11.633 --> 00:04:13.200 And over the decades 79 00:04:13.200 --> 00:04:17.600 Goddard's gotten pretty good at explaining just how laser altimetry works. 80 00:04:17.600 --> 00:04:19.100 This is a laser altimeter. 81 00:04:19.100 --> 00:04:21.466 What it does is it sends a short pulse of light. 82 00:04:21.466 --> 00:04:25.600 From a moving platform that's observing a surface, an airplane, a satellite. 83 00:04:25.600 --> 00:04:27.433 Gets a reflection straight back off the surface. 84 00:04:27.433 --> 00:04:31.466 We record that reflection and the time very precisely. 85 00:04:31.466 --> 00:04:34.600 Of the pulse from the spacecraft down to the surface and back again. 86 00:04:34.600 --> 00:04:37.133 Which allows us to measure the range to the surface. 87 00:04:37.133 --> 00:04:39.600 When that's done repeatedly in orbit, you can build up a map. 88 00:04:39.600 --> 00:04:41.766 [music hit] 89 00:04:41.766 --> 00:04:42.766 The fast rate of 90 00:04:42.766 --> 00:04:45.800 light pulses and the small footprint allow lidar 91 00:04:45.800 --> 00:04:49.433 to measure with a much finer scale than traditional radars. 92 00:04:50.000 --> 00:04:53.700 They had a big review, and the leading radar guy 93 00:04:53.700 --> 00:04:58.200 that had flown radars to Venus, Gordon Pettengill, at the end said, well, 94 00:04:58.200 --> 00:05:00.100 I don't know about you folks, 95 00:05:00.100 --> 00:05:01.700 the laser is better. 96 00:05:01.700 --> 00:05:05.333 In time, Goddard would become a leader in lidar 97 00:05:05.333 --> 00:05:09.766 in mapping our Earth and planets with unprecedented precision. 98 00:05:09.766 --> 00:05:13.666 But for now, they had to actually build the first one. 99 00:05:13.666 --> 00:05:16.266 The requirements were, of course, we were at a much higher orbit, 100 00:05:16.300 --> 00:05:20.500 and orbit was faster than going around the Moon so we needed a larger telescope, 101 00:05:20.500 --> 00:05:25.066 needed a more sensitive detector, we needed more laser energy. 102 00:05:25.433 --> 00:05:29.666 So in order to put our concept together, we had to gather a team 103 00:05:31.233 --> 00:05:31.733 and then we 104 00:05:31.733 --> 00:05:35.533 had to convince the management that this was not a crazy idea 105 00:05:35.533 --> 00:05:39.166 and that we actually had a realistic chance of making this happen. 106 00:05:39.533 --> 00:05:41.000 We worked a lot of hours. 107 00:05:41.000 --> 00:05:42.966 I can remember 108 00:05:43.400 --> 00:05:47.433 Jim talking about, you know, working ten-hour days, and I was doing about the same. 109 00:05:47.433 --> 00:05:50.500 But, you know, it really it really didn't matter 110 00:05:50.500 --> 00:05:53.600 because it was so exciting 111 00:05:53.600 --> 00:05:58.000 to be working on something that was going to actually map Mars. 112 00:05:58.233 --> 00:06:02.233 I was fresh out of getting my master's degree in computer engineering. 113 00:06:03.000 --> 00:06:03.600 I was young. 114 00:06:03.600 --> 00:06:06.800 I mean, I was it was I had to really dive in deep. 115 00:06:06.800 --> 00:06:12.000 I had to spend about two years working with the team on algorithms. 116 00:06:12.266 --> 00:06:15.866 How were we going to find the surface of the of Mars, how we were going 117 00:06:15.900 --> 00:06:19.533 to track it, how we're going to compute all the precise ranges. 118 00:06:19.800 --> 00:06:22.200 And we were just, we were sort of making our way. 119 00:06:22.200 --> 00:06:25.033 We were, we were defining the rules as we went. 120 00:06:25.400 --> 00:06:28.500 We finished the instrument pretty much on time. 121 00:06:28.500 --> 00:06:31.466 And certainly, as they said in the letter to me, look, 122 00:06:31.466 --> 00:06:35.633 if you don't make it on time and in budget, we will fly a brick instead. 123 00:06:35.866 --> 00:06:38.500 Okay? We're not going to hold this mission up. 124 00:06:39.266 --> 00:06:40.933 I mean, I knew about planetary missions. 125 00:06:40.933 --> 00:06:42.966 They have to go within certain windows. 126 00:06:42.966 --> 00:06:44.933 But anyway, we made it alright. 127 00:06:44.933 --> 00:06:47.100 [music] 128 00:06:47.100 --> 00:06:51.966 Five, four, three, two, one. 129 00:06:52.700 --> 00:06:53.866 And liftoff. 130 00:06:53.866 --> 00:06:55.433 Liftoff of the Titan III 131 00:06:55.433 --> 00:06:59.933 rocket with the Mars Observer and America's return to the Red Planet. 132 00:07:00.533 --> 00:07:03.300 And the vehicle has cleared the tower. 133 00:07:03.300 --> 00:07:06.533 We've got X-band launch at Canberra. 134 00:07:06.533 --> 00:07:08.433 All right! 135 00:07:08.433 --> 00:07:14.666 [applause] 136 00:07:14.666 --> 00:07:16.166 A very happy crew. 137 00:07:17.466 --> 00:07:20.633 The Mars Observer is on its way to Mars. 138 00:07:21.700 --> 00:07:24.333 Trajectory is right on the money. 139 00:07:24.333 --> 00:07:29.700 [music] 140 00:07:29.700 --> 00:07:30.966 We've assumed 141 00:07:30.966 --> 00:07:35.333 that the spacecraft properly executed its orbit insertion sequence, 142 00:07:35.333 --> 00:07:38.466 and we presume the spacecraft is in orbit about Mars. 143 00:07:38.466 --> 00:07:43.433 But we have no positive confirmation of that because as for the last three days, 144 00:07:43.433 --> 00:07:45.933 we have no communication with the spacecraft. 145 00:07:45.933 --> 00:07:47.700 --That is to say you simply don't know what happened to that. 146 00:07:47.700 --> 00:07:50.100 It could be in orbit. It could have flown past the planet. 147 00:07:50.100 --> 00:07:52.233 What are the scientists doing to relieve the tension in there? 148 00:07:52.233 --> 00:07:55.666 Screaming loudly, probably. [laughter] 149 00:07:55.833 --> 00:07:58.900 We still don't have communication with the spacecraft. 150 00:07:58.900 --> 00:08:03.833 However, we are very hopeful and we're cautiously optimistic 151 00:08:03.833 --> 00:08:07.100 that communication will be restored-- --Every day without communications 152 00:08:07.100 --> 00:08:10.200 clearly lessens our probability of success. 153 00:08:10.200 --> 00:08:12.466 --Though, you know, we give up? 154 00:08:12.466 --> 00:08:14.566 We have not given up. 155 00:08:14.566 --> 00:08:21.133 [music] 156 00:08:21.133 --> 00:08:24.066 But I was not concerned about the spacecraft. 157 00:08:24.066 --> 00:08:27.000 It never crossed my mind the spacecraft would let us down. 158 00:08:27.000 --> 00:08:30.033 So this was a blow in the sense of, wow, 159 00:08:30.033 --> 00:08:32.066 something I completely didn't expect.