1 00:00:08,270 --> 00:00:05,630 welcome to NASA headquarters in 2 00:00:10,160 --> 00:00:08,280 Washington we are less than three weeks 3 00:00:12,169 --> 00:00:10,170 away from launching a pair of earth 4 00:00:14,240 --> 00:00:12,179 orbiting spacecraft they're literally 5 00:00:16,970 --> 00:00:14,250 going to take on the weight of the world 6 00:00:30,710 --> 00:00:16,980 it's the grace follow-on mission or 7 00:00:33,440 --> 00:00:30,720 grace fo take a look water is one of the 8 00:00:36,799 --> 00:00:33,450 main indicators of how the planet is 9 00:00:38,840 --> 00:00:36,809 responding to our evolving climate we 10 00:00:40,160 --> 00:00:38,850 build our civilization around the 11 00:00:42,170 --> 00:00:40,170 climate that we had and the water 12 00:00:43,970 --> 00:00:42,180 resources that we have and if those are 13 00:00:48,080 --> 00:00:43,980 changing that can have a profound impact 14 00:00:50,240 --> 00:00:48,090 on how we operate our society grace and 15 00:00:51,830 --> 00:00:50,250 grace follow on measure the motion of 16 00:00:53,810 --> 00:00:51,840 water around the earth and they measure 17 00:00:55,700 --> 00:00:53,820 that in all forms of water water that's 18 00:00:57,350 --> 00:00:55,710 stored underground water in the ocean 19 00:00:59,540 --> 00:00:57,360 water that's frozen in the form of 20 00:01:08,450 --> 00:00:59,550 glaciers so all of that together grace 21 00:01:11,960 --> 00:01:08,460 can measure grace fall one is a mission 22 00:01:13,399 --> 00:01:11,970 to measure how water is distributed on 23 00:01:15,469 --> 00:01:13,409 the planet and how that changes from 24 00:01:17,630 --> 00:01:15,479 month to month grace stands for Gravity 25 00:01:18,890 --> 00:01:17,640 Recovery and climate experiment it's a 26 00:01:22,100 --> 00:01:18,900 follow-on mission to this mission called 27 00:01:23,840 --> 00:01:22,110 grace that we launched in 2002 and that 28 00:01:25,249 --> 00:01:23,850 mission just ended a few months ago and 29 00:01:26,270 --> 00:01:25,259 grace phone's gonna pick up and continue 30 00:01:28,520 --> 00:01:26,280 that science legacy 31 00:01:30,080 --> 00:01:28,530 even though grace flew for 15 years 32 00:01:32,600 --> 00:01:30,090 climbing is one of those things which 33 00:01:33,890 --> 00:01:32,610 takes place on decadal timescales 34 00:01:35,749 --> 00:01:33,900 it's really important that we look at 35 00:01:37,700 --> 00:01:35,759 these trends over longer time period 36 00:01:41,300 --> 00:01:37,710 where we can establish the forces which 37 00:01:44,510 --> 00:01:41,310 are driving them one follows the other 38 00:01:46,399 --> 00:01:44,520 and between them they accurately track 39 00:01:51,080 --> 00:01:46,409 the distance between the two satellites 40 00:01:52,240 --> 00:01:51,090 and as they fly over changes in mass on 41 00:01:53,710 --> 00:01:52,250 the earth and 42 00:01:56,380 --> 00:01:53,720 back and forth then we track those 43 00:01:58,060 --> 00:01:56,390 little changes very accurate and we do 44 00:02:00,670 --> 00:01:58,070 that with Global Positioning System 45 00:02:02,440 --> 00:02:00,680 satellite information and with star 46 00:02:06,880 --> 00:02:02,450 cameras that are onboard the two 47 00:02:10,270 --> 00:02:06,890 spacecraft I think there's an increasing 48 00:02:12,699 --> 00:02:10,280 awareness and consciousness around the 49 00:02:15,100 --> 00:02:12,709 earth that water is a critical resource 50 00:02:17,170 --> 00:02:15,110 and that the sea level is rising the 51 00:02:20,380 --> 00:02:17,180 polar caps are melting and that all 52 00:02:23,290 --> 00:02:20,390 these have long-term ramifications on 53 00:02:25,360 --> 00:02:23,300 how we live the grace following 54 00:02:27,160 --> 00:02:25,370 measurements give us very clear and 55 00:02:28,720 --> 00:02:27,170 tangible information so we can make 56 00:02:36,400 --> 00:02:28,730 sound decisions in the future of how we 57 00:02:38,979 --> 00:02:36,410 manage our resources hi I'm Karen Fox 58 00:02:40,750 --> 00:02:38,989 and welcome to this NASA media briefing 59 00:02:43,810 --> 00:02:40,760 on our next Earth observing mission 60 00:02:45,970 --> 00:02:43,820 grace follow-on grace stands for the 61 00:02:48,520 --> 00:02:45,980 Gravity Recovery and climate experiment 62 00:02:51,250 --> 00:02:48,530 it's a joint mission between NASA and 63 00:02:53,530 --> 00:02:51,260 Germany grace follow-on will carry on 64 00:02:55,120 --> 00:02:53,540 from a former mission grace together a 65 00:02:57,660 --> 00:02:55,130 unique data record that tracks our 66 00:03:00,820 --> 00:02:57,670 planets water cycle ice sheets and more 67 00:03:02,350 --> 00:03:00,830 our briefing is in two parts today first 68 00:03:04,090 --> 00:03:02,360 we'll look at the amazing science the 69 00:03:06,280 --> 00:03:04,100 mission will enable and how that will 70 00:03:07,750 --> 00:03:06,290 benefit people around the world then 71 00:03:10,000 --> 00:03:07,760 we'll switch to talking about between 72 00:03:11,530 --> 00:03:10,010 spacecraft themselves and how launch 73 00:03:14,320 --> 00:03:11,540 preparations are progressing in 74 00:03:15,820 --> 00:03:14,330 California after each part we'll be 75 00:03:18,250 --> 00:03:15,830 taking questions from the press both 76 00:03:19,750 --> 00:03:18,260 here and on the phone and if you're 77 00:03:21,580 --> 00:03:19,760 watching on NASA TV you can ask 78 00:03:23,470 --> 00:03:21,590 questions to just post it on social 79 00:03:27,940 --> 00:03:23,480 media during the briefing with the 80 00:03:30,759 --> 00:03:27,950 hashtag ask NASA let's get started first 81 00:03:33,250 --> 00:03:30,769 up the science we have three experts 82 00:03:35,890 --> 00:03:33,260 here today in our studio is Michael 83 00:03:37,210 --> 00:03:35,900 Watkins the grace follow-on science lead 84 00:03:40,900 --> 00:03:37,220 and director of NASA's Jet Propulsion 85 00:03:43,590 --> 00:03:40,910 Laboratory Frank Webb the grace 86 00:03:47,380 --> 00:03:43,600 follow-on project scientist at JPL and 87 00:03:50,289 --> 00:03:47,390 joining us via Skype from over 15 - 88 00:03:52,390 --> 00:03:50,299 Germany is Frank Flexner the grace 89 00:03:54,610 --> 00:03:52,400 follow-on project manager at the German 90 00:03:57,789 --> 00:03:54,620 Research Center for geosciences also 91 00:03:59,920 --> 00:03:57,799 known as G FZ which is NASA's primary 92 00:04:00,790 --> 00:03:59,930 mission partner we're going to start 93 00:04:03,670 --> 00:04:00,800 with the basics 94 00:04:05,890 --> 00:04:03,680 Michael tell me about grace follow-on 95 00:04:06,100 --> 00:04:05,900 and also its predecessor grace what did 96 00:04:07,690 --> 00:04:06,110 they 97 00:04:10,060 --> 00:04:07,700 - well thanks Karen it's a pleasure to 98 00:04:12,730 --> 00:04:10,070 be here so grace and grace follow-on are 99 00:04:13,900 --> 00:04:12,740 some of NASA's most unique missions so 100 00:04:15,820 --> 00:04:13,910 what grace has done and what grace 101 00:04:19,060 --> 00:04:15,830 fallin will do shortly after its launch 102 00:04:20,320 --> 00:04:19,070 is map the Earth's water in motion now 103 00:04:22,120 --> 00:04:20,330 what's fascinating about grace is it 104 00:04:23,920 --> 00:04:22,130 does it not by looking at the surface of 105 00:04:26,380 --> 00:04:23,930 the earth not by looking at water or 106 00:04:27,880 --> 00:04:26,390 bouncing a radar off off the water but 107 00:04:30,400 --> 00:04:27,890 by actually measuring the weight of the 108 00:04:32,710 --> 00:04:30,410 water so it actually is able to tell how 109 00:04:34,120 --> 00:04:32,720 much water is in a given location on the 110 00:04:36,340 --> 00:04:34,130 earth and how that's changing over time 111 00:04:37,600 --> 00:04:36,350 and what grace was able to observe from 112 00:04:39,280 --> 00:04:37,610 that is because water takes many 113 00:04:40,770 --> 00:04:39,290 different forms sometimes it's in the 114 00:04:42,640 --> 00:04:40,780 form of ground water deep underground 115 00:04:45,640 --> 00:04:42,650 sometimes it's in the form of polar 116 00:04:47,620 --> 00:04:45,650 icecaps sometimes it could be in the 117 00:04:48,850 --> 00:04:47,630 form of ocean water moving around winds 118 00:04:50,920 --> 00:04:48,860 and circle oh sure circles you can't 119 00:04:52,990 --> 00:04:50,930 pile water up and another more in one 120 00:04:54,640 --> 00:04:53,000 place in another place and grace 121 00:04:56,170 --> 00:04:54,650 observes all of that complete water 122 00:04:57,910 --> 00:04:56,180 cycle of the earth and how it changes 123 00:04:59,680 --> 00:04:57,920 over time and it's very unique in that 124 00:05:01,990 --> 00:04:59,690 sense because it measures water in all 125 00:05:04,150 --> 00:05:02,000 forms and because it does it with this 126 00:05:06,580 --> 00:05:04,160 bathroom scale methodology of actually 127 00:05:09,160 --> 00:05:06,590 weighing the weight of the water as it 128 00:05:10,930 --> 00:05:09,170 moves around the earth so we've had 15 129 00:05:13,180 --> 00:05:10,940 years now of this kind of data that 130 00:05:14,710 --> 00:05:13,190 you're talking about what has grace told 131 00:05:16,870 --> 00:05:14,720 us about the earth that we didn't know 132 00:05:18,460 --> 00:05:16,880 before so let's take a look at the at 133 00:05:22,270 --> 00:05:18,470 this graphic so as you said we have 15 134 00:05:24,400 --> 00:05:22,280 years of gray's data and and what grace 135 00:05:26,650 --> 00:05:24,410 has shown us is there's significant 136 00:05:28,270 --> 00:05:26,660 changes in every part of the world and 137 00:05:30,190 --> 00:05:28,280 how much water is stored in each part of 138 00:05:32,170 --> 00:05:30,200 the world now one of the unique things 139 00:05:34,659 --> 00:05:32,180 about this plot is that you notice 140 00:05:35,980 --> 00:05:34,669 Grace's has measurements of everywhere 141 00:05:37,480 --> 00:05:35,990 in the world everywhere on land and 142 00:05:39,760 --> 00:05:37,490 fight a little in the oceans as well and 143 00:05:41,409 --> 00:05:39,770 what you can see is sometimes that again 144 00:05:43,690 --> 00:05:41,419 that's ice ice sheets that have changed 145 00:05:45,190 --> 00:05:43,700 sometimes it's it's aquifer storage but 146 00:05:46,840 --> 00:05:45,200 almost every part of the world has been 147 00:05:48,610 --> 00:05:46,850 observed by grace and has a story to 148 00:05:50,440 --> 00:05:48,620 tell and that's actually resulted in 149 00:05:52,330 --> 00:05:50,450 grace coming up with some of the the 150 00:05:54,580 --> 00:05:52,340 most scientific findings of seismic 151 00:05:56,740 --> 00:05:54,590 publications of any mission in recent 152 00:05:58,540 --> 00:05:56,750 years in earth science because it's just 153 00:06:00,760 --> 00:05:58,550 so broad in what he can tell us about 154 00:06:05,200 --> 00:06:00,770 about the earth so we take a look at 155 00:06:07,000 --> 00:06:05,210 this here this is the average trend that 156 00:06:09,719 --> 00:06:07,010 grace has seen over the 15 years that it 157 00:06:12,520 --> 00:06:09,729 was in orbit from 2002 through 2017 158 00:06:14,290 --> 00:06:12,530 the biggest signals are actually up in 159 00:06:16,510 --> 00:06:14,300 the poles so the areas that are reddish 160 00:06:19,029 --> 00:06:16,520 in color are areas where water mass has 161 00:06:19,570 --> 00:06:19,039 gone away from those regions and so the 162 00:06:21,189 --> 00:06:19,580 the area 163 00:06:23,350 --> 00:06:21,199 have the most water mass loss are 164 00:06:25,240 --> 00:06:23,360 actually in Greenland for example you 165 00:06:26,890 --> 00:06:25,250 see all the red colors there in in 166 00:06:28,629 --> 00:06:26,900 Greenland that's actually ice that's 167 00:06:30,520 --> 00:06:28,639 melted off the Greenland ice caps and 168 00:06:33,219 --> 00:06:30,530 you can see the same thing over in 169 00:06:35,200 --> 00:06:33,229 Alaska and and and down in the West 170 00:06:37,089 --> 00:06:35,210 Antarctic Peninsula and so those have 171 00:06:38,679 --> 00:06:37,099 been contributing a significant amount 172 00:06:41,080 --> 00:06:38,689 about one third of sea-level rise that 173 00:06:42,610 --> 00:06:41,090 we observe comes from polar ice melting 174 00:06:44,170 --> 00:06:42,620 that good that grace has observed and it 175 00:06:45,580 --> 00:06:44,180 was actually not well known before we 176 00:06:47,589 --> 00:06:45,590 launched grace it was it was not clear 177 00:06:48,820 --> 00:06:47,599 how much that was contributing to sea 178 00:06:51,159 --> 00:06:48,830 level and and how much the ice sheets 179 00:06:53,170 --> 00:06:51,169 were changing but it's also fascinating 180 00:06:55,809 --> 00:06:53,180 that you see a lot of blobs of green and 181 00:06:57,730 --> 00:06:55,819 and red that of course are not ice and 182 00:06:59,320 --> 00:06:57,740 that's areas where it's either been a 183 00:07:01,149 --> 00:06:59,330 drought and folks have been using 184 00:07:03,580 --> 00:07:01,159 groundwater pumping groundwater for 185 00:07:06,100 --> 00:07:03,590 agriculture for human use for for other 186 00:07:08,499 --> 00:07:06,110 purposes for irrigation in other cases 187 00:07:10,510 --> 00:07:08,509 we have it green areas where it's been 188 00:07:12,519 --> 00:07:10,520 heavy rain it's been it's been flooded 189 00:07:13,689 --> 00:07:12,529 even in some cases so we all know some 190 00:07:14,830 --> 00:07:13,699 years sometimes you have a couple years 191 00:07:16,930 --> 00:07:14,840 that are drying a couple years that are 192 00:07:18,550 --> 00:07:16,940 wet what you can't always tell us how 193 00:07:20,379 --> 00:07:18,560 did that how did that how did that water 194 00:07:21,640 --> 00:07:20,389 get deep into the earth you know it was 195 00:07:23,230 --> 00:07:21,650 a drought that I just lose water from 196 00:07:25,420 --> 00:07:23,240 the surface or did I lose it very deep 197 00:07:26,589 --> 00:07:25,430 down and what do I do about replenishing 198 00:07:29,619 --> 00:07:26,599 that and it can they observe it being 199 00:07:30,490 --> 00:07:29,629 replenished when we have wetter years so 200 00:07:32,170 --> 00:07:30,500 if you look at the areas that are 201 00:07:34,230 --> 00:07:32,180 greenish those tend to be areas where 202 00:07:36,579 --> 00:07:34,240 it's been heavy rainfall and replenished 203 00:07:38,469 --> 00:07:36,589 areas where it's red are areas where 204 00:07:41,170 --> 00:07:38,479 there's been significant drought and use 205 00:07:43,600 --> 00:07:41,180 of a fairly precious groundwater and 206 00:07:45,189 --> 00:07:43,610 some of these areas are here in the 207 00:07:47,589 --> 00:07:45,199 United States the Texas drought in 208 00:07:48,969 --> 00:07:47,599 California some of them are in parts of 209 00:07:50,950 --> 00:07:48,979 the developing world where where the 210 00:07:52,600 --> 00:07:50,960 infrastructure may not be able to to 211 00:07:54,579 --> 00:07:52,610 respond as quickly to that too those 212 00:07:55,959 --> 00:07:54,589 droughts and loss of ground water so 213 00:07:57,820 --> 00:07:55,969 this is very important data and it's 214 00:07:59,680 --> 00:07:57,830 it's very important to how we understand 215 00:08:01,899 --> 00:07:59,690 our home planet and and how it's 216 00:08:03,700 --> 00:08:01,909 changing thank you very much 217 00:08:05,680 --> 00:08:03,710 Frank I'm going to ask you to do a 218 00:08:07,390 --> 00:08:05,690 deeper dive into some of these areas but 219 00:08:09,430 --> 00:08:07,400 Michael has been telling us about let's 220 00:08:11,769 --> 00:08:09,440 start off with the global water cycle 221 00:08:15,249 --> 00:08:11,779 tell us what it is and how great is fall 222 00:08:17,260 --> 00:08:15,259 inside that area so so the water in the 223 00:08:19,390 --> 00:08:17,270 water cycle play an important role in 224 00:08:21,189 --> 00:08:19,400 the earth system you know water you know 225 00:08:23,980 --> 00:08:21,199 it's it's necessary for sustaining life 226 00:08:27,070 --> 00:08:23,990 it's an important media for transporting 227 00:08:29,800 --> 00:08:27,080 you know heat on the planet and it's a 228 00:08:32,620 --> 00:08:29,810 vital resource for our civilization now 229 00:08:33,380 --> 00:08:32,630 in these charts these charts are just 230 00:08:35,030 --> 00:08:33,390 going to illustrate 231 00:08:37,580 --> 00:08:35,040 you know water comes in many forms to us 232 00:08:41,450 --> 00:08:37,590 it's like rain falls as rain it falls as 233 00:08:46,280 --> 00:08:41,460 snow its surface water in rivers and 234 00:08:48,500 --> 00:08:46,290 lakes it's also you know locked up his 235 00:08:51,020 --> 00:08:48,510 frozen water and ice and ice sheets as 236 00:08:53,920 --> 00:08:51,030 well as water in the ground that we pump 237 00:08:56,060 --> 00:08:53,930 out for irrigation and for drinking and 238 00:08:57,830 --> 00:08:56,070 understanding and also water in the 239 00:09:00,860 --> 00:08:57,840 ocean as well and understanding you know 240 00:09:02,290 --> 00:09:00,870 the water cycle and the trends in the 241 00:09:04,580 --> 00:09:02,300 water cycle is very important for us to 242 00:09:07,550 --> 00:09:04,590 understand this resource and manage it 243 00:09:09,260 --> 00:09:07,560 for our use so you mentioned a number of 244 00:09:10,910 --> 00:09:09,270 different types of water we're tracking 245 00:09:12,740 --> 00:09:10,920 let's go into frozen water it tell us 246 00:09:14,990 --> 00:09:12,750 what the ice sheets and the glaciers so 247 00:09:16,790 --> 00:09:15,000 so ice sheets and glaciers are the 248 00:09:19,490 --> 00:09:16,800 largest you know freshwater resources on 249 00:09:20,960 --> 00:09:19,500 the planet they took tens to hundreds of 250 00:09:23,060 --> 00:09:20,970 thousands of years to develop they 251 00:09:24,050 --> 00:09:23,070 developed in places where the planet you 252 00:09:25,880 --> 00:09:24,060 know where there's were more 253 00:09:27,920 --> 00:09:25,890 precipitation or snow fell every year 254 00:09:31,250 --> 00:09:27,930 then was lost through melts during 255 00:09:33,500 --> 00:09:31,260 during that year and so snow in in water 256 00:09:35,480 --> 00:09:33,510 or snow accumulated they're accumulating 257 00:09:38,540 --> 00:09:35,490 this water resource now in this video 258 00:09:40,580 --> 00:09:38,550 clip here this is a animation of grace 259 00:09:42,080 --> 00:09:40,590 data and as Mike mentioned you know 260 00:09:44,180 --> 00:09:42,090 about the trends and the trends and 261 00:09:47,150 --> 00:09:44,190 trends around the globe here we can see 262 00:09:50,030 --> 00:09:47,160 more detail how the grace data allows us 263 00:09:52,180 --> 00:09:50,040 to see how Greenland won these the 264 00:09:55,340 --> 00:09:52,190 largest frozen ice reservoir that we 265 00:09:57,410 --> 00:09:55,350 that is melting right now is evolving we 266 00:09:59,180 --> 00:09:57,420 can see on a month-to-month basis the 267 00:10:01,760 --> 00:09:59,190 variations the seasonal variations we 268 00:10:03,020 --> 00:10:01,770 can see geographically where the changes 269 00:10:04,790 --> 00:10:03,030 are taking place where it's draining 270 00:10:07,160 --> 00:10:04,800 from and all this data helps scientists 271 00:10:10,340 --> 00:10:07,170 understand the forces which are driving 272 00:10:12,680 --> 00:10:10,350 the the loss of ice from Greenland the 273 00:10:14,060 --> 00:10:12,690 melting of water that is going into the 274 00:10:17,780 --> 00:10:14,070 oceans right now and contributing a 275 00:10:19,940 --> 00:10:17,790 sea-level rise so from there oh there's 276 00:10:21,110 --> 00:10:19,950 more oh yeah and so there's also in this 277 00:10:23,720 --> 00:10:21,120 clip who this is similarly for 278 00:10:25,490 --> 00:10:23,730 Antarctica you can see that we again we 279 00:10:28,760 --> 00:10:25,500 have you know monthly measurements from 280 00:10:30,770 --> 00:10:28,770 grace of how Antarctica is losing you 281 00:10:32,780 --> 00:10:30,780 know ice ice mass and that's going to 282 00:10:35,330 --> 00:10:32,790 the oceans you guys to see again the the 283 00:10:37,400 --> 00:10:35,340 geographical distribution means that you 284 00:10:39,950 --> 00:10:37,410 know in some parts of Antarctica are 285 00:10:42,560 --> 00:10:39,960 accumulating snow and some are losing 286 00:10:44,720 --> 00:10:42,570 it's physically Western Antarctica but 287 00:10:46,809 --> 00:10:44,730 the net effect is most is our crow is 288 00:10:49,929 --> 00:10:46,819 losing water losing water mass and 289 00:10:53,199 --> 00:10:49,939 going into the oceans we you know it's 290 00:10:55,840 --> 00:10:53,209 you know it's like 280 Giga tons of 291 00:10:57,489 --> 00:10:55,850 water per year from Greenland and 120 292 00:11:00,519 --> 00:10:57,499 Giga tons of water per year from 293 00:11:02,919 --> 00:11:00,529 Antarctica what's a good time so a Giga 294 00:11:05,169 --> 00:11:02,929 ton is a cube of water a kilometer in 295 00:11:07,150 --> 00:11:05,179 size and this graphic here just shows 296 00:11:09,579 --> 00:11:07,160 what that cube looks like sitting on 297 00:11:12,179 --> 00:11:09,589 Manhattan it's equivalent to about 298 00:11:15,099 --> 00:11:12,189 400,000 Olympic sized swimming pools and 299 00:11:17,469 --> 00:11:15,109 you know the ice mass loss from 300 00:11:20,199 --> 00:11:17,479 Greenland alone contributes about a 301 00:11:23,259 --> 00:11:20,209 third of the sea-level rise right that 302 00:11:25,210 --> 00:11:23,269 we were seeing these currently all right 303 00:11:27,609 --> 00:11:25,220 so we just did the ice let's bring it a 304 00:11:30,639 --> 00:11:27,619 little closer to home can you tell us a 305 00:11:32,379 --> 00:11:30,649 little bit about the kind of water that 306 00:11:34,359 --> 00:11:32,389 people are relying on every day what is 307 00:11:35,979 --> 00:11:34,369 what's going on with that sure so some 308 00:11:39,189 --> 00:11:35,989 of the trends that Mike showed in his in 309 00:11:40,449 --> 00:11:39,199 his chart were were for not only ice but 310 00:11:43,409 --> 00:11:40,459 also for ground water and ground water 311 00:11:46,989 --> 00:11:43,419 depletion and this this animation here 312 00:11:49,659 --> 00:11:46,999 video shows the loss of water mass in 313 00:11:52,149 --> 00:11:49,669 the western United States from 2003 at 314 00:11:54,189 --> 00:11:52,159 about 2013 and this was a period during 315 00:11:55,629 --> 00:11:54,199 some some droughts in California in the 316 00:11:57,819 --> 00:11:55,639 western US and you can see on a monthly 317 00:11:59,499 --> 00:11:57,829 basis we were able to sort of track how 318 00:12:01,179 --> 00:11:59,509 much you know water was stored in 319 00:12:03,309 --> 00:12:01,189 California in the western US we can 320 00:12:05,439 --> 00:12:03,319 actually weigh it with the grace data 321 00:12:06,699 --> 00:12:05,449 and you can see sort of variations in 322 00:12:07,749 --> 00:12:06,709 the amount of water was there some years 323 00:12:09,939 --> 00:12:07,759 a little wetter sand there's a little 324 00:12:11,679 --> 00:12:09,949 drier and this allows us to track you 325 00:12:14,349 --> 00:12:11,689 know the water changes and help to 326 00:12:17,859 --> 00:12:14,359 establish you know the causes of the 327 00:12:20,859 --> 00:12:17,869 water scarcity in this region thank you 328 00:12:22,960 --> 00:12:20,869 so much Frank scientists have also put 329 00:12:24,519 --> 00:12:22,970 grace data to other uses that directly 330 00:12:27,249 --> 00:12:24,529 impact everyday life around the world 331 00:12:28,899 --> 00:12:27,259 we're going to go now to Frank Flexner 332 00:12:31,029 --> 00:12:28,909 in Germany to talk about those 333 00:12:34,239 --> 00:12:31,039 specifically flood monitoring and 334 00:12:35,979 --> 00:12:34,249 weather forecasting Frank can you start 335 00:12:38,799 --> 00:12:35,989 out telling us how you've been using 336 00:12:42,749 --> 00:12:38,809 Frank Det sorry using grace data for 337 00:12:46,029 --> 00:12:42,759 tracking floods yes of course Karen 338 00:12:48,189 --> 00:12:46,039 flood forecasting systems require new 339 00:12:50,559 --> 00:12:48,199 real-time data to estimate the 340 00:12:54,249 --> 00:12:50,569 likeliness of flood events and to 341 00:12:56,409 --> 00:12:54,259 predict the evolution typically times 342 00:12:59,620 --> 00:12:56,419 for larger river basins are a few days 343 00:13:01,660 --> 00:12:59,630 and challenging the conventional ways 344 00:13:03,780 --> 00:13:01,670 data processing for the application and 345 00:13:06,100 --> 00:13:03,790 risk and Emergency Management 346 00:13:08,980 --> 00:13:06,110 therefore members of the European 347 00:13:10,930 --> 00:13:08,990 science team developed within a European 348 00:13:13,720 --> 00:13:10,940 Commission funded object which was 349 00:13:16,870 --> 00:13:13,730 called European gravity service for 350 00:13:19,090 --> 00:13:16,880 improved Emergency Management gravity 351 00:13:22,690 --> 00:13:19,100 field solutions which are provided in 352 00:13:25,690 --> 00:13:22,700 near real-time and with daily resolution 353 00:13:27,280 --> 00:13:25,700 from this gravity solutions we have them 354 00:13:30,400 --> 00:13:27,290 derived grace based 355 00:13:34,330 --> 00:13:30,410 wetness indices so if you start the 356 00:13:37,900 --> 00:13:34,340 video you see that with this innovative 357 00:13:40,750 --> 00:13:37,910 data we could drag the generation and 358 00:13:43,440 --> 00:13:40,760 the development of historical flood 359 00:13:47,800 --> 00:13:43,450 events for example what is shown here 360 00:13:50,560 --> 00:13:47,810 the April 2006 flood in the Danube Basin 361 00:13:53,560 --> 00:13:50,570 was a lead time of about six weeks 362 00:13:56,470 --> 00:13:53,570 compared to the river flow data at the 363 00:13:59,020 --> 00:13:56,480 outlet of the basin and operational test 364 00:14:02,350 --> 00:13:59,030 runs were also performed between April 365 00:14:04,780 --> 00:14:02,360 and June 2017 within the German space 366 00:14:07,750 --> 00:14:04,790 agency center for satellite-based crisis 367 00:14:11,440 --> 00:14:07,760 information and he turned out that this 368 00:14:14,440 --> 00:14:11,450 near real-time data are really extremely 369 00:14:17,860 --> 00:14:14,450 useful for early warning so if you look 370 00:14:21,010 --> 00:14:17,870 to the next slide you see this gray 371 00:14:23,740 --> 00:14:21,020 space to our wetness indices which have 372 00:14:26,320 --> 00:14:23,750 been P operationally implemented in the 373 00:14:29,110 --> 00:14:26,330 global flood awareness system of the 374 00:14:31,210 --> 00:14:29,120 European Commission in red you can see 375 00:14:35,350 --> 00:14:31,220 drier and in blue wetter than normal 376 00:14:39,030 --> 00:14:35,360 conditions so we are really trying to 377 00:14:41,500 --> 00:14:39,040 make a service out of the grace data and 378 00:14:44,070 --> 00:14:41,510 how will grace follow on continue 379 00:14:48,160 --> 00:14:44,080 helping with weather forecasts as well 380 00:14:52,450 --> 00:14:48,170 yeah so to explains this please start 381 00:14:54,640 --> 00:14:52,460 the next video so while the main Global 382 00:14:56,710 --> 00:14:54,650 Positioning System receivers on the top 383 00:14:59,710 --> 00:14:56,720 of the gray satellites were used for 384 00:15:02,200 --> 00:14:59,720 precise orbit determination a set of 385 00:15:04,510 --> 00:15:02,210 secondary GPS antenna sides the take 386 00:15:06,130 --> 00:15:04,520 sides of satellites and which are 387 00:15:08,470 --> 00:15:06,140 measuring the bending of the signals 388 00:15:11,650 --> 00:15:08,480 between Grace and the GPS satellites 389 00:15:13,150 --> 00:15:11,660 that were low offers arising and this 390 00:15:14,980 --> 00:15:13,160 way is a GPS signal 391 00:15:17,680 --> 00:15:14,990 it's grace and pass through the Earth's 392 00:15:18,550 --> 00:15:17,690 atmosphere which is also known as the 393 00:15:22,269 --> 00:15:18,560 occultation 394 00:15:24,939 --> 00:15:22,279 the GPS radio waves are added slightly 395 00:15:28,329 --> 00:15:24,949 as a pass through the atmosphere due to 396 00:15:30,610 --> 00:15:28,339 refractive effects and these changes can 397 00:15:33,309 --> 00:15:30,620 also be analyzed to create atmosphere 398 00:15:36,460 --> 00:15:33,319 for fights including RAF activity 399 00:15:41,410 --> 00:15:36,470 temperature or humidity what you can see 400 00:15:44,499 --> 00:15:41,420 on the slide left Champa's gfz satellite 401 00:15:47,309 --> 00:15:44,509 launched in 2000 with objectives of 402 00:15:50,740 --> 00:15:47,319 gravity and magnetic field ordering and 403 00:15:54,730 --> 00:15:50,750 atmospheric sounding so tram can be seen 404 00:15:57,009 --> 00:15:54,740 as a precursor of grace since 2006 gfz 405 00:15:59,619 --> 00:15:57,019 provides his temperature and humidity 406 00:16:02,889 --> 00:15:59,629 profiles operationally to various 407 00:16:06,009 --> 00:16:02,899 numerical weather services on a 24/7 408 00:16:08,530 --> 00:16:06,019 basis and an average delay of less than 409 00:16:11,860 --> 00:16:08,540 two hours to improve weather forecasts 410 00:16:15,220 --> 00:16:11,870 and to reach this stringent requirement 411 00:16:18,910 --> 00:16:15,230 of the weather services we have also 412 00:16:21,249 --> 00:16:18,920 implemented a receiving station with two 413 00:16:23,170 --> 00:16:21,259 antennas in Spitsbergen ears in aw spoil 414 00:16:27,309 --> 00:16:23,180 which you could see at the right of this 415 00:16:29,319 --> 00:16:27,319 plot and which I a ballute outload the 416 00:16:32,410 --> 00:16:29,329 echo occultation measurements nearly 417 00:16:35,050 --> 00:16:32,420 every orbit and this station will also 418 00:16:37,210 --> 00:16:35,060 become the primary downlink station for 419 00:16:39,699 --> 00:16:37,220 queries follow-on so one of the 420 00:16:42,939 --> 00:16:39,709 secondary objectives of the graceful on 421 00:16:46,059 --> 00:16:42,949 mission will be to derive at least 200 422 00:16:50,259 --> 00:16:46,069 of these daily temperature and humidity 423 00:16:52,210 --> 00:16:50,269 profiles thank you so much Frank that 424 00:16:54,460 --> 00:16:52,220 wraps up our discussion of the science 425 00:16:56,559 --> 00:16:54,470 of grace follow-on thank you so much to 426 00:16:59,199 --> 00:16:56,569 all of our experts here we're now going 427 00:17:00,850 --> 00:16:59,209 to take your questions remember that if 428 00:17:02,740 --> 00:17:00,860 you are watching on NASA TV all you have 429 00:17:07,960 --> 00:17:02,750 to do to ask a question via social media 430 00:17:10,929 --> 00:17:07,970 is to use the hashtag ask NASA and with 431 00:17:15,579 --> 00:17:10,939 that we have our first question from one 432 00:17:16,120 --> 00:17:15,589 of the media in our studio from science 433 00:17:18,699 --> 00:17:16,130 magazine 434 00:17:20,470 --> 00:17:18,709 I was wondering originally grace and 435 00:17:22,990 --> 00:17:20,480 grace follow-on were planned to overlap 436 00:17:24,460 --> 00:17:23,000 to aid in data calibration between them 437 00:17:26,470 --> 00:17:24,470 to get those long-term measures and 438 00:17:26,740 --> 00:17:26,480 since they won't overlap I'm wondering 439 00:17:30,610 --> 00:17:26,750 how 440 00:17:32,530 --> 00:17:30,620 you'll handle that let's take a crack at 441 00:17:34,900 --> 00:17:32,540 that so this is a good question 442 00:17:35,650 --> 00:17:34,910 we like you always like overlap because 443 00:17:37,060 --> 00:17:35,660 you want to make sure that the 444 00:17:39,640 --> 00:17:37,070 measurements are not in some way biased 445 00:17:41,200 --> 00:17:39,650 in some unpredictable way and that 446 00:17:42,430 --> 00:17:41,210 everything's consistent between the two 447 00:17:44,890 --> 00:17:42,440 measurement systems particularly for 448 00:17:47,170 --> 00:17:44,900 things like long term continuity in the 449 00:17:48,430 --> 00:17:47,180 case of grace and grace follow on the 450 00:17:50,740 --> 00:17:48,440 measurement because it's a change 451 00:17:52,960 --> 00:17:50,750 measurement it doesn't lend itself to 452 00:17:55,210 --> 00:17:52,970 being biased in in convey many 453 00:17:57,070 --> 00:17:55,220 conventional measurements are so the 454 00:17:58,810 --> 00:17:57,080 requirement for overlap is less critical 455 00:18:00,190 --> 00:17:58,820 than it might be for some other types of 456 00:18:01,510 --> 00:18:00,200 missions and grace is really measuring 457 00:18:04,300 --> 00:18:01,520 the derivative of things how fast things 458 00:18:06,400 --> 00:18:04,310 are changing and it's not the absolute 459 00:18:07,540 --> 00:18:06,410 amount of water but really the change 460 00:18:10,990 --> 00:18:07,550 and that's that's something that's 461 00:18:12,520 --> 00:18:11,000 harder to be biased but but but we want 462 00:18:14,860 --> 00:18:12,530 to double check anyway and the way we 463 00:18:17,380 --> 00:18:14,870 double check is by looking at other 464 00:18:18,490 --> 00:18:17,390 satellites less precise than grace that 465 00:18:22,140 --> 00:18:18,500 have been observed in the gravity field 466 00:18:24,880 --> 00:18:22,150 that very very long wavelength recourse 467 00:18:26,740 --> 00:18:24,890 spatial scales so they can kind of see 468 00:18:28,270 --> 00:18:26,750 yes Greenland was doing about this or 469 00:18:30,610 --> 00:18:28,280 Antarctic was doing about that or there 470 00:18:32,650 --> 00:18:30,620 were large scale changes in the northern 471 00:18:34,600 --> 00:18:32,660 hemisphere or southern hemisphere due to 472 00:18:35,920 --> 00:18:34,610 water storage and we can compare those 473 00:18:37,770 --> 00:18:35,930 and make sure that that when you 474 00:18:40,030 --> 00:18:37,780 interpolate the last grace data point 475 00:18:41,680 --> 00:18:40,040 those intermediate course points and the 476 00:18:44,530 --> 00:18:41,690 first grace follow-on point that those 477 00:18:46,360 --> 00:18:44,540 all look consistent so we believe it 478 00:18:48,310 --> 00:18:46,370 will be it will be satisfactory to have 479 00:18:51,040 --> 00:18:48,320 this fairly short gap of about a year 480 00:18:52,510 --> 00:18:51,050 year and a half all right we have 481 00:18:55,180 --> 00:18:52,520 another question from the room 482 00:18:57,220 --> 00:18:55,190 Randy Shostak reporter with a us at the 483 00:18:59,110 --> 00:18:57,230 American Geophysical Union thanks very 484 00:19:01,330 --> 00:18:59,120 much for doing this briefing I wonder if 485 00:19:03,370 --> 00:19:01,340 you could just tell me what in your 486 00:19:05,770 --> 00:19:03,380 estimation is the most startling most 487 00:19:07,360 --> 00:19:05,780 important findings that you've gotten 488 00:19:11,680 --> 00:19:07,370 from grace and what are your biggest 489 00:19:13,540 --> 00:19:11,690 hopes from grace follow-on associ from 490 00:19:17,050 --> 00:19:13,550 grace I think I think the rate of which 491 00:19:18,130 --> 00:19:17,060 the polar caps were were losing mass was 492 00:19:20,110 --> 00:19:18,140 something that was a little surprising 493 00:19:22,840 --> 00:19:20,120 to folks you know when we launched grace 494 00:19:24,040 --> 00:19:22,850 it wasn't clear how fast the polar 495 00:19:26,110 --> 00:19:24,050 sheets were changing 496 00:19:28,360 --> 00:19:26,120 I think grace was give the first clear 497 00:19:29,200 --> 00:19:28,370 picture with what's going on and of 498 00:19:31,630 --> 00:19:29,210 course that's been followed up with 499 00:19:33,820 --> 00:19:31,640 other more precise measurements for 500 00:19:36,580 --> 00:19:33,830 local areas like with radar or the 501 00:19:38,169 --> 00:19:36,590 upcoming icesat-2 mission but I think 502 00:19:39,520 --> 00:19:38,179 generally understanding how the how the 503 00:19:40,720 --> 00:19:39,530 polar caps are evolving is probably the 504 00:19:42,850 --> 00:19:40,730 biggest surprise from grace 505 00:19:44,920 --> 00:19:42,860 along with just the clarity that grace 506 00:19:46,780 --> 00:19:44,930 gave for the for the hydrological basins 507 00:19:47,800 --> 00:19:46,790 around the world for for groundwater and 508 00:19:50,950 --> 00:19:47,810 Frankie won't talk about Gracie 509 00:19:52,780 --> 00:19:50,960 following yeah and let me just add to 510 00:19:55,030 --> 00:19:52,790 that Mike to me one of the most 511 00:19:58,480 --> 00:19:55,040 interesting and saying exciting things 512 00:19:59,950 --> 00:19:58,490 was you know the understanding of how 513 00:20:01,780 --> 00:19:59,960 when you know the ice caps are melting 514 00:20:04,480 --> 00:20:01,790 and they're contributing you know mass 515 00:20:05,980 --> 00:20:04,490 to the oceans but you know in two 516 00:20:08,110 --> 00:20:05,990 thousand ten or eleven there was a 517 00:20:09,910 --> 00:20:08,120 slight sort of like you know dip in the 518 00:20:11,740 --> 00:20:09,920 rate of rise and actually reversal and 519 00:20:13,930 --> 00:20:11,750 rate of rise of sea level and that was 520 00:20:15,670 --> 00:20:13,940 related to more water being stored on 521 00:20:17,970 --> 00:20:15,680 land and so we could see mass was being 522 00:20:20,950 --> 00:20:17,980 lost from the ice caps nice sheets 523 00:20:22,360 --> 00:20:20,960 Greenland Antarctica corny and going but 524 00:20:24,790 --> 00:20:22,370 it wasn't all going to the ocean so it 525 00:20:26,980 --> 00:20:24,800 was getting stored on land it was later 526 00:20:28,930 --> 00:20:26,990 released you know through you know just 527 00:20:30,940 --> 00:20:28,940 normal processes for water running off 528 00:20:32,530 --> 00:20:30,950 land I think one thing that's important 529 00:20:35,200 --> 00:20:32,540 to follow up on that is the fact that 530 00:20:36,790 --> 00:20:35,210 grace observes what happens in many 531 00:20:38,530 --> 00:20:36,800 components of the hydrological cycle 532 00:20:40,720 --> 00:20:38,540 allows you to actually answer the 533 00:20:43,120 --> 00:20:40,730 question water left here where did it go 534 00:20:44,530 --> 00:20:43,130 and in the case for that Frank's talking 535 00:20:46,150 --> 00:20:44,540 about her or other case we actually see 536 00:20:47,920 --> 00:20:46,160 it go from one place and show up 537 00:20:49,510 --> 00:20:47,930 somewhere else and that allow scientists 538 00:20:51,190 --> 00:20:49,520 to really try to unfold exactly how 539 00:20:52,630 --> 00:20:51,200 water is transported at what rate and 540 00:20:55,440 --> 00:20:52,640 what are the most important processes 541 00:20:57,520 --> 00:20:55,450 that govern the water cycle on the earth 542 00:21:00,520 --> 00:20:57,530 alright we now have some questions from 543 00:21:02,260 --> 00:21:00,530 social media a user on Twitter has the 544 00:21:03,970 --> 00:21:02,270 following question if the grace 545 00:21:05,830 --> 00:21:03,980 follow-on mission can measure water 546 00:21:08,140 --> 00:21:05,840 underground does that mean you can also 547 00:21:11,800 --> 00:21:08,150 find and track new underground lakes and 548 00:21:13,420 --> 00:21:11,810 rivers it can so the first thing to 549 00:21:16,000 --> 00:21:13,430 remember always about grace is that it 550 00:21:17,800 --> 00:21:16,010 senses the change in water and not the 551 00:21:19,570 --> 00:21:17,810 absolute content of water so it doesn't 552 00:21:21,340 --> 00:21:19,580 tell you you have ten feet of water in 553 00:21:24,190 --> 00:21:21,350 that well it tells you you use 10 feet 554 00:21:26,890 --> 00:21:24,200 of water since last month so in areas 555 00:21:28,990 --> 00:21:26,900 where the aquifers are are varying quite 556 00:21:31,060 --> 00:21:29,000 a bit it is possible to actually go and 557 00:21:33,760 --> 00:21:31,070 look for areas of water storage or water 558 00:21:35,350 --> 00:21:33,770 depletion that are that have not 559 00:21:37,240 --> 00:21:35,360 currently been known and and there 560 00:21:39,370 --> 00:21:37,250 actually have been a few aquifers found 561 00:21:40,510 --> 00:21:39,380 using various techniques you know in 562 00:21:43,540 --> 00:21:40,520 parts of the world that are they're not 563 00:21:46,060 --> 00:21:43,550 widely used for irrigation and and not 564 00:21:49,660 --> 00:21:46,070 not widely used haven't have a lot of 565 00:21:51,730 --> 00:21:49,670 wells in them are already we have 566 00:21:53,860 --> 00:21:51,740 another question for social media now 567 00:21:55,690 --> 00:21:53,870 Tricia Patterson will like to know how 568 00:21:57,220 --> 00:21:55,700 and when will data from this mission be 569 00:21:59,049 --> 00:21:57,230 share it with the public is there an 570 00:22:02,740 --> 00:21:59,059 option for ongoing sharing of the 571 00:22:04,510 --> 00:22:02,750 findings so the the mission will be 572 00:22:06,669 --> 00:22:04,520 shared immediately as soon as we we get 573 00:22:08,590 --> 00:22:06,679 it and analyze it so the mission 574 00:22:11,740 --> 00:22:08,600 launches and we have about a 90 day 575 00:22:13,120 --> 00:22:11,750 period of checkout and then during that 576 00:22:14,980 --> 00:22:13,130 period we'll be collecting data we're 577 00:22:16,000 --> 00:22:14,990 collecting gravity data we'll be making 578 00:22:17,919 --> 00:22:16,010 sure the instruments are working and 579 00:22:19,480 --> 00:22:17,929 everything's you know operating well and 580 00:22:21,519 --> 00:22:19,490 then shortly after that we'll start 581 00:22:23,590 --> 00:22:21,529 releasing maybe 120 days after the 582 00:22:25,630 --> 00:22:23,600 initial check-out our first data 583 00:22:27,519 --> 00:22:25,640 products and that will then you'll be 584 00:22:30,159 --> 00:22:27,529 able to add those to the existing sort 585 00:22:32,169 --> 00:22:30,169 of database of grace data and move 586 00:22:33,970 --> 00:22:32,179 forward so it all be you know freely 587 00:22:37,500 --> 00:22:33,980 available Populi available as soon as I 588 00:22:40,000 --> 00:22:37,510 you know 120 days or so after launch 589 00:22:42,850 --> 00:22:40,010 thank you we have one last question 590 00:22:44,980 --> 00:22:42,860 coming in from social media Twitter user 591 00:22:48,850 --> 00:22:44,990 Jaimie Meyer wants to know which rocket 592 00:22:51,909 --> 00:22:48,860 will launch grace follow-on so so grace 593 00:22:55,299 --> 00:22:51,919 followings being launched on a balcony 594 00:22:57,060 --> 00:22:55,309 from Vandenberg on on May 19th is the 595 00:23:00,760 --> 00:22:57,070 scheduled date it's part of a rideshare 596 00:23:02,560 --> 00:23:00,770 with the Iridium communications so we'll 597 00:23:03,940 --> 00:23:02,570 be you know riding along with five of 598 00:23:05,680 --> 00:23:03,950 their satellites and then we'll be will 599 00:23:06,730 --> 00:23:05,690 be a release first and then they will go 600 00:23:08,440 --> 00:23:06,740 into their orbit and release their 601 00:23:09,820 --> 00:23:08,450 satellites we wouldn't talk quite a bit 602 00:23:13,960 --> 00:23:09,830 more about that in the in the second 603 00:23:16,210 --> 00:23:13,970 part of this briefing we had some great 604 00:23:17,950 --> 00:23:16,220 questions thank you so much now we're 605 00:23:19,289 --> 00:23:17,960 going to switch gears we're gonna start 606 00:23:21,820 --> 00:23:19,299 talking about the twin spacecraft 607 00:23:22,899 --> 00:23:21,830 themselves and how they work we're also 608 00:23:25,060 --> 00:23:22,909 going to take a look at launch 609 00:23:30,570 --> 00:23:25,070 preparations in California so stay with 610 00:25:15,639 --> 00:23:35,810 [Music] 611 00:25:21,019 --> 00:25:18,560 we are back with more on the grace 612 00:25:23,180 --> 00:25:21,029 follow-on mission which as we speak is 613 00:25:24,259 --> 00:25:23,190 currently at Vandenberg Air Force Base 614 00:25:26,830 --> 00:25:24,269 in California 615 00:25:28,759 --> 00:25:26,840 getting ready for a launch on May 19th 616 00:25:30,889 --> 00:25:28,769 here with us to talk about the 617 00:25:33,739 --> 00:25:30,899 spacecraft and mission operations our 618 00:25:35,810 --> 00:25:33,749 David Jarrett who is the grace follow-on 619 00:25:37,369 --> 00:25:35,820 program executive in the earth science 620 00:25:40,789 --> 00:25:37,379 division at NASA headquarters 621 00:25:43,940 --> 00:25:40,799 we have Phil Morton the grace follow-on 622 00:25:46,249 --> 00:25:43,950 project manager at JPL and again joining 623 00:25:48,349 --> 00:25:46,259 us from Germany via Skype we have Frank 624 00:25:50,119 --> 00:25:48,359 Flexner who is the grace follow-on 625 00:25:53,509 --> 00:25:50,129 project manager at the German Research 626 00:25:54,169 --> 00:25:53,519 Center for geosciences so Dave let's 627 00:25:56,450 --> 00:25:54,179 start with you 628 00:25:58,190 --> 00:25:56,460 I understand that grace follow-on is 629 00:26:00,649 --> 00:25:58,200 really very different from the typical 630 00:26:02,570 --> 00:26:00,659 earth-observing spacecraft that we have 631 00:26:04,759 --> 00:26:02,580 can you tell us a little bit about how 632 00:26:06,769 --> 00:26:04,769 it compares to some of the other things 633 00:26:08,869 --> 00:26:06,779 in NASA's science fleet that's right 634 00:26:11,570 --> 00:26:08,879 Karen we have a variety of Earth 635 00:26:13,759 --> 00:26:11,580 observing satellites circling the earth 636 00:26:16,969 --> 00:26:13,769 right now that are measuring different 637 00:26:20,899 --> 00:26:16,979 aspects of the earth from particles 638 00:26:23,539 --> 00:26:20,909 circling the earth to land masses to 639 00:26:26,690 --> 00:26:23,549 even the clouds that are circling the 640 00:26:29,719 --> 00:26:26,700 planet if you go to take a look at this 641 00:26:32,839 --> 00:26:29,729 animation here you can see that NASA 642 00:26:35,329 --> 00:26:32,849 currently has about 17 different 643 00:26:38,049 --> 00:26:35,339 satellites orbiting the Earth in many 644 00:26:42,379 --> 00:26:38,059 different orbits most of these 645 00:26:47,599 --> 00:26:42,389 satellites are in GOC or low-earth orbit 646 00:26:50,749 --> 00:26:47,609 and they generally measure things in 647 00:26:55,149 --> 00:26:50,759 certain ways if you could go to the next 648 00:26:58,339 --> 00:26:55,159 graphic the two ways that these 649 00:27:01,609 --> 00:26:58,349 spacecraft measure different 650 00:27:05,060 --> 00:27:01,619 characteristics are a passive way which 651 00:27:07,609 --> 00:27:05,070 acts like a camera and collects the 652 00:27:09,709 --> 00:27:07,619 reflected light off of the planet and 653 00:27:11,659 --> 00:27:09,719 then the instruments break these down 654 00:27:13,030 --> 00:27:11,669 into various wavelengths that are then 655 00:27:16,030 --> 00:27:13,040 analyzed for 656 00:27:21,610 --> 00:27:16,040 the different characteristics that we're 657 00:27:23,950 --> 00:27:21,620 looking for second type of instrument is 658 00:27:26,980 --> 00:27:23,960 an active instrument like radar or lidar 659 00:27:29,799 --> 00:27:26,990 that sends out an active pulse or an 660 00:27:31,690 --> 00:27:29,809 active later laser pulse that then 661 00:27:34,539 --> 00:27:31,700 rebounce is back off of whatever 662 00:27:38,500 --> 00:27:34,549 particle it reflects off of and then 663 00:27:43,390 --> 00:27:38,510 that beam is an analyzed for different 664 00:27:44,919 --> 00:27:43,400 characteristics unlike these two ways of 665 00:27:47,260 --> 00:27:44,929 collecting data 666 00:27:50,070 --> 00:27:47,270 grace follow-on is not your average 667 00:27:53,320 --> 00:27:50,080 everyday or science type of mission 668 00:27:55,510 --> 00:27:53,330 spacecraft don't essentially see 669 00:27:58,150 --> 00:27:55,520 anything on the ground or measure 670 00:28:00,580 --> 00:27:58,160 anything on the ground the actual of the 671 00:28:04,000 --> 00:28:00,590 two spacecraft are actually the science 672 00:28:07,750 --> 00:28:04,010 instrument when you combine them as can 673 00:28:09,940 --> 00:28:07,760 be seen in this video here the way the 674 00:28:12,640 --> 00:28:09,950 the major measurement or prime 675 00:28:15,520 --> 00:28:12,650 measurement of the grace follow-on 676 00:28:17,100 --> 00:28:15,530 mission is a very precise measurement of 677 00:28:22,390 --> 00:28:17,110 the distance between the two satellites 678 00:28:24,130 --> 00:28:22,400 and as the as the satellites pass over 679 00:28:26,440 --> 00:28:24,140 different portions of the earth the 680 00:28:28,799 --> 00:28:26,450 distance between the satellites change 681 00:28:32,680 --> 00:28:28,809 based on the current pull of gravity 682 00:28:35,500 --> 00:28:32,690 below them for instance when the first 683 00:28:37,900 --> 00:28:35,510 spacecraft passes over a mountain range 684 00:28:40,120 --> 00:28:37,910 such as the Himalayas it'll speed up 685 00:28:43,630 --> 00:28:40,130 slightly and increase the distance 686 00:28:46,120 --> 00:28:43,640 between the two satellites as the second 687 00:28:48,370 --> 00:28:46,130 satellite approaches the same mountain 688 00:28:51,370 --> 00:28:48,380 range it'll it too will increase speed 689 00:28:53,980 --> 00:28:51,380 and therefore decrease the space between 690 00:28:56,500 --> 00:28:53,990 the two satellites and this goes on and 691 00:28:59,860 --> 00:28:56,510 on as the both satellites orbit the 692 00:29:02,350 --> 00:28:59,870 earth and from this data scientists can 693 00:29:06,100 --> 00:29:02,360 estimate the gravity field to great 694 00:29:09,310 --> 00:29:06,110 precision for the entire planet thank 695 00:29:12,010 --> 00:29:09,320 you very much now let's go to Phil can 696 00:29:13,000 --> 00:29:12,020 you step us through the kinds of things 697 00:29:14,860 --> 00:29:13,010 Dave was telling us about tell us 698 00:29:16,450 --> 00:29:14,870 exactly how grace follow-on does its 699 00:29:18,430 --> 00:29:16,460 work and what are the key components I'm 700 00:29:20,890 --> 00:29:18,440 sure Karen and we brought these models 701 00:29:23,590 --> 00:29:20,900 to show you the various pieces and parts 702 00:29:26,260 --> 00:29:23,600 of the satellite on the outside on the 703 00:29:26,980 --> 00:29:26,270 front end here you can see the microwave 704 00:29:28,840 --> 00:29:26,990 instrument 705 00:29:31,659 --> 00:29:28,850 antenna these are the two antennas that 706 00:29:34,419 --> 00:29:31,669 the two spacecraft point at each other 707 00:29:36,519 --> 00:29:34,429 they used to microwave frequencies to 708 00:29:39,549 --> 00:29:36,529 measure the distance between the two 709 00:29:43,029 --> 00:29:39,559 spacecraft they fly about a hundred and 710 00:29:44,950 --> 00:29:43,039 thirty seven miles apart at that kind of 711 00:29:46,990 --> 00:29:44,960 a distance we can measure distance 712 00:29:51,730 --> 00:29:47,000 changes about the thickness of a blood 713 00:29:53,649 --> 00:29:51,740 cell you can also see two ports here 714 00:29:55,480 --> 00:29:53,659 these are baffles for the laser ranging 715 00:29:56,950 --> 00:29:55,490 interferometer this is a technology 716 00:29:59,710 --> 00:29:56,960 demonstration instrument that we've 717 00:30:02,950 --> 00:29:59,720 added to great follow on and there we'll 718 00:30:05,440 --> 00:30:02,960 use a laser beam bouncing between the 719 00:30:07,510 --> 00:30:05,450 two satellites to essentially accomplish 720 00:30:11,169 --> 00:30:07,520 this same measurement as the microwave 721 00:30:13,419 --> 00:30:11,179 but more accurately some other things to 722 00:30:16,779 --> 00:30:13,429 notice about the spacecraft solar arrays 723 00:30:20,169 --> 00:30:16,789 on the top and the two sides give us the 724 00:30:22,029 --> 00:30:20,179 power that we need these cutouts here or 725 00:30:25,240 --> 00:30:22,039 there on the top and the two sides are 726 00:30:28,480 --> 00:30:25,250 forced our camera baffles we use three 727 00:30:31,360 --> 00:30:28,490 star cameras to map our location in 728 00:30:33,220 --> 00:30:31,370 space as we're flying and taking these 729 00:30:36,220 --> 00:30:33,230 measurements we also have on top a 730 00:30:39,370 --> 00:30:36,230 precision GPS antenna and we use GPS 731 00:30:42,220 --> 00:30:39,380 data to also map the distance changes 732 00:30:45,010 --> 00:30:42,230 relative to earth and then finally on 733 00:30:47,500 --> 00:30:45,020 the back side you can see the GPS 734 00:30:51,639 --> 00:30:47,510 occultation tena that Frank was talking 735 00:30:53,500 --> 00:30:51,649 about earlier this we use to look at GPS 736 00:30:55,480 --> 00:30:53,510 signals as they rise and set over the 737 00:30:58,570 --> 00:30:55,490 horizon to measure moisture in the 738 00:31:01,539 --> 00:30:58,580 atmosphere and how do you put a complex 739 00:31:03,909 --> 00:31:01,549 spacecraft like this together oh well it 740 00:31:08,529 --> 00:31:03,919 is complicated we have a video here you 741 00:31:13,600 --> 00:31:08,539 can see this is film of the spacecraft 742 00:31:15,340 --> 00:31:13,610 being assembled at Airbus Airbus is 743 00:31:17,620 --> 00:31:15,350 located in southern Germany in 744 00:31:19,029 --> 00:31:17,630 Friedreich's - they're our primary 745 00:31:23,620 --> 00:31:19,039 contractor for the build of the two 746 00:31:26,590 --> 00:31:23,630 satellites it's quite a compact inside 747 00:31:31,000 --> 00:31:26,600 you can see the fuel tanks the solar 748 00:31:33,159 --> 00:31:31,010 arrays being added here one of the 749 00:31:35,950 --> 00:31:33,169 challenges we had was integrating the 750 00:31:38,560 --> 00:31:35,960 laser ranging interferometer into the 751 00:31:39,970 --> 00:31:38,570 system as its stood for grace or is it 752 00:31:42,370 --> 00:31:39,980 was done on grace 753 00:31:44,610 --> 00:31:42,380 here's a shot of the accelerometer this 754 00:31:48,370 --> 00:31:44,620 is a key component inside the spacecraft 755 00:31:49,750 --> 00:31:48,380 very carefully aligned with the triple 756 00:31:53,530 --> 00:31:49,760 mirror assembly part of the laser 757 00:31:56,680 --> 00:31:53,540 instrument also the star cameras all the 758 00:31:59,580 --> 00:31:56,690 optical alignments are very critical and 759 00:32:01,930 --> 00:31:59,590 then you can see the whole unit being 760 00:32:05,710 --> 00:32:01,940 dropped down into the very heart of the 761 00:32:07,390 --> 00:32:05,720 spacecraft these alignments are critical 762 00:32:10,150 --> 00:32:07,400 so critical they're done first and then 763 00:32:12,070 --> 00:32:10,160 we align the rest of the instruments to 764 00:32:14,919 --> 00:32:12,080 those make sure everything's properly 765 00:32:17,950 --> 00:32:14,929 and mechanically aligned thank you so 766 00:32:21,100 --> 00:32:17,960 much ville we are going to turn back now 767 00:32:22,260 --> 00:32:21,110 to frank fleckner in germany phil just 768 00:32:24,400 --> 00:32:22,270 explained that there's a new technology 769 00:32:26,440 --> 00:32:24,410 demonstration instrument that wasn't on 770 00:32:27,850 --> 00:32:26,450 the first grade's mission Frank can you 771 00:32:32,289 --> 00:32:27,860 tell us more about that and what do you 772 00:32:36,010 --> 00:32:32,299 hope to achieve with it yeah sure so on 773 00:32:39,010 --> 00:32:36,020 the next image you can see a sketch of a 774 00:32:41,860 --> 00:32:39,020 laser ranging interferometer as you have 775 00:32:44,110 --> 00:32:41,870 heard in Phil's overview it was a real 776 00:32:46,450 --> 00:32:44,120 challenge to implement another 777 00:32:49,150 --> 00:32:46,460 instrument into the already fully 778 00:32:51,100 --> 00:32:49,160 equipped satellite the laser ranging 779 00:32:54,100 --> 00:32:51,110 interferometer is a technology 780 00:32:56,950 --> 00:32:54,110 demonstrator for future next-generation 781 00:32:59,680 --> 00:32:56,960 gravity missions to improve the accuracy 782 00:33:02,320 --> 00:32:59,690 of the inter-satellite ranging it is 783 00:33:04,450 --> 00:33:02,330 important to mention that the success of 784 00:33:07,299 --> 00:33:04,460 grace follow-on will not rely on this 785 00:33:09,070 --> 00:33:07,309 technology demonstrator if it should not 786 00:33:11,799 --> 00:33:09,080 work as planned the gravity field 787 00:33:14,500 --> 00:33:11,809 modeling will be based on the microwave 788 00:33:15,789 --> 00:33:14,510 instrument only and grace follow-on will 789 00:33:18,669 --> 00:33:15,799 it still be successful 790 00:33:20,980 --> 00:33:18,679 the laser ranging interferometer is an 791 00:33:22,570 --> 00:33:20,990 excellent example to my opinion of a 792 00:33:23,740 --> 00:33:22,580 cooperative project was a great 793 00:33:26,980 --> 00:33:23,750 partnership 794 00:33:29,530 --> 00:33:26,990 u.s. focuses on very electronics the 795 00:33:32,620 --> 00:33:29,540 cavity and the procurement of the laser 796 00:33:34,510 --> 00:33:32,630 from Germany and Germany is focusing on 797 00:33:36,700 --> 00:33:34,520 the optical paths for example the 798 00:33:40,030 --> 00:33:36,710 optical range of a triple mirror 799 00:33:42,130 --> 00:33:40,040 assembly on the optical bench assembly 800 00:33:45,220 --> 00:33:42,140 the receive beam from the distant 801 00:33:46,740 --> 00:33:45,230 spacecraft is infinite with a small 802 00:33:49,560 --> 00:33:46,750 fraction 803 00:33:51,840 --> 00:33:49,570 for local oscillator being the larger 804 00:33:54,180 --> 00:33:51,850 fraction of the local oscillator beam is 805 00:33:57,120 --> 00:33:54,190 rate all deflected by a triple mirror 806 00:34:00,270 --> 00:33:57,130 assembly and sent back to the distant 807 00:34:03,060 --> 00:34:00,280 spacecraft the assembly consists of 808 00:34:06,060 --> 00:34:03,070 three perpendicular murals mounted into 809 00:34:09,570 --> 00:34:06,070 a rigid structure and works like a conic 810 00:34:13,200 --> 00:34:09,580 you reflect on the cavity is used for 811 00:34:16,889 --> 00:34:13,210 frequency stabilization of a laser and 812 00:34:20,369 --> 00:34:16,899 with all these components implemented on 813 00:34:23,610 --> 00:34:20,379 both satellites as a so-called racetrack 814 00:34:26,340 --> 00:34:23,620 configuration is established between the 815 00:34:29,100 --> 00:34:26,350 satellite and the inter-satellite range 816 00:34:33,270 --> 00:34:29,110 is continuously measured with a position 817 00:34:36,659 --> 00:34:33,280 of about 80 nanometer which is twice the 818 00:34:39,659 --> 00:34:36,669 size of a hepatitis-b viewers over 819 00:34:43,200 --> 00:34:39,669 distance of Los Angeles to San Diego for 820 00:34:43,950 --> 00:34:43,210 example so on the next slide you see top 821 00:34:46,320 --> 00:34:43,960 left 822 00:34:49,230 --> 00:34:46,330 these are little reflectors which have 823 00:34:51,600 --> 00:34:49,240 been provided by G of Z and which are 824 00:34:54,899 --> 00:34:51,610 mounted on the bottom of each of the two 825 00:34:57,240 --> 00:34:54,909 satellites we use a network of about 20 826 00:34:59,850 --> 00:34:57,250 ground stations which centrales a beam 827 00:35:02,610 --> 00:34:59,860 to the later reflector on the bottom 828 00:35:05,820 --> 00:35:02,620 right you see as an example the G of Z 829 00:35:07,560 --> 00:35:05,830 station in Potsdam Germany by comparing 830 00:35:10,170 --> 00:35:07,570 the time delay when the signal was sent 831 00:35:12,690 --> 00:35:10,180 and again received at relays our station 832 00:35:15,360 --> 00:35:12,700 the two-way range can be obtained with 833 00:35:18,060 --> 00:35:15,370 millimeter precision this serves for an 834 00:35:22,380 --> 00:35:18,070 independent control of a GPS derived of 835 00:35:24,330 --> 00:35:22,390 it now in addition to the important 836 00:35:26,490 --> 00:35:24,340 science it will do and the technology it 837 00:35:29,100 --> 00:35:26,500 uses we're excited here at NASA about 838 00:35:30,450 --> 00:35:29,110 grace follow-on for other reasons - the 839 00:35:34,230 --> 00:35:30,460 mission marks the continuation of a 840 00:35:35,550 --> 00:35:34,240 major u.s. German collaboration Dave can 841 00:35:36,830 --> 00:35:35,560 you talk a little bit about that 842 00:35:38,610 --> 00:35:36,840 collaboration and tell us in general 843 00:35:41,250 --> 00:35:38,620 what these kinds of international 844 00:35:43,620 --> 00:35:41,260 partnerships bring to NASA absolutely 845 00:35:45,930 --> 00:35:43,630 nASA has been working for many many 846 00:35:49,220 --> 00:35:45,940 years with our international partners in 847 00:35:52,320 --> 00:35:49,230 collaboration to conduct earth science 848 00:35:53,880 --> 00:35:52,330 measurements it is indeed a global 849 00:35:57,329 --> 00:35:53,890 effort and 850 00:35:59,699 --> 00:35:57,339 the data is very important to everyone 851 00:36:02,609 --> 00:35:59,709 around the world as this graphic shows 852 00:36:03,390 --> 00:36:02,619 here we have several missions both 853 00:36:06,779 --> 00:36:03,400 on-orbit 854 00:36:11,519 --> 00:36:06,789 and in development in cooperation with 855 00:36:12,900 --> 00:36:11,529 our many international partners part of 856 00:36:16,890 --> 00:36:12,910 the reason for international 857 00:36:19,910 --> 00:36:16,900 collaboration is to be able to reduce 858 00:36:25,529 --> 00:36:19,920 the costs for each contributing country 859 00:36:29,449 --> 00:36:25,539 for instance for grace follow-on we're 860 00:36:30,749 --> 00:36:29,459 working with gfz on this we worked on 861 00:36:36,719 --> 00:36:30,759 grace 862 00:36:39,420 --> 00:36:36,729 Agency and what we both get out of this 863 00:36:44,729 --> 00:36:39,430 essentially is more bang for the buck or 864 00:36:46,640 --> 00:36:44,739 an euro in this case for the investments 865 00:36:52,140 --> 00:36:46,650 that these different countries have made 866 00:36:53,370 --> 00:36:52,150 for for the measured gravity 867 00:36:56,400 --> 00:36:53,380 measurements we've been working with 868 00:36:59,519 --> 00:36:56,410 Germany since the 1990s first on the 869 00:37:02,249 --> 00:36:59,529 grace mission starting in 1998 and now 870 00:37:06,239 --> 00:37:02,259 continuing this successful partnership 871 00:37:10,079 --> 00:37:06,249 with gfz with Frank fleckner as the lead 872 00:37:15,089 --> 00:37:10,089 of the German side with their 873 00:37:18,239 --> 00:37:15,099 contributions together we look forward 874 00:37:20,609 --> 00:37:18,249 to a very good mission as Frank 875 00:37:24,329 --> 00:37:20,619 fleckner ed said earlier the Germans are 876 00:37:28,819 --> 00:37:24,339 contributing the launch mission 877 00:37:33,890 --> 00:37:28,829 operations the optics of the laser 878 00:37:38,299 --> 00:37:33,900 ranging interferometer and the laser 879 00:37:41,609 --> 00:37:38,309 retroreflectors the u.s. is providing 880 00:37:49,289 --> 00:37:41,619 overall project management the two 881 00:37:50,689 --> 00:37:49,299 spacecraft the accelerometers and and 882 00:37:53,579 --> 00:37:50,699 that's about it 883 00:37:55,199 --> 00:37:53,589 wonderful thank you so much Dave let's 884 00:37:56,910 --> 00:37:55,209 hear from the German side - we're gonna 885 00:37:59,630 --> 00:37:56,920 go again to Frank to hear about the 886 00:38:03,059 --> 00:37:59,640 partnership from the German perspective 887 00:38:05,430 --> 00:38:03,069 yes OG fzy has a long tradition in 888 00:38:07,140 --> 00:38:05,440 gravity field determination for example 889 00:38:11,520 --> 00:38:07,150 jet has buried 890 00:38:14,330 --> 00:38:11,530 operator hm with giant satellite in 2000 891 00:38:18,060 --> 00:38:14,340 which was a kind of precursor of grace 892 00:38:20,400 --> 00:38:18,070 this first time continuous high-low 893 00:38:23,970 --> 00:38:20,410 satellite to satellite tracking between 894 00:38:26,310 --> 00:38:23,980 champ and the GPS satellites and for the 895 00:38:28,860 --> 00:38:26,320 very first time flown accelerometer for 896 00:38:32,040 --> 00:38:28,870 gravity field improvement the 897 00:38:35,130 --> 00:38:32,050 collaboration in the u.s. German science 898 00:38:38,910 --> 00:38:35,140 data system and between the US and 899 00:38:41,550 --> 00:38:38,920 European science data teams helps gfz to 900 00:38:44,310 --> 00:38:41,560 improve gravity field and earth system 901 00:38:46,470 --> 00:38:44,320 modeling expertise the technology 902 00:38:49,710 --> 00:38:46,480 demonstrator of the laser ranging 903 00:38:52,980 --> 00:38:49,720 interferometer will enable German Space 904 00:38:55,680 --> 00:38:52,990 Agency DLR and German industry to 905 00:38:58,380 --> 00:38:55,690 prepare for next-generation gravity 906 00:39:01,440 --> 00:38:58,390 field missions and it's also a win-win 907 00:39:04,020 --> 00:39:01,450 situation for the German taxpayer as the 908 00:39:07,350 --> 00:39:04,030 cost was german contributed items like 909 00:39:10,110 --> 00:39:07,360 free alive a science data system to 910 00:39:12,660 --> 00:39:10,120 launch or mission operations or we 911 00:39:15,120 --> 00:39:12,670 funded as between graceful on satellites 912 00:39:19,320 --> 00:39:15,130 has been bought by cheap air from Airbus 913 00:39:21,210 --> 00:39:19,330 in Germany thank you very much now it's 914 00:39:24,330 --> 00:39:21,220 time to focus on an essential part of 915 00:39:25,650 --> 00:39:24,340 any space mission the launch and of 916 00:39:27,480 --> 00:39:25,660 course after that comes the mission 917 00:39:29,880 --> 00:39:27,490 operations to maintain the spacecraft 918 00:39:32,250 --> 00:39:29,890 once it's on orbit and doing its work so 919 00:39:35,670 --> 00:39:32,260 Frank can you step us through these key 920 00:39:38,610 --> 00:39:35,680 elements yes of course 921 00:39:40,770 --> 00:39:38,620 so gfz has signed the right track 922 00:39:43,440 --> 00:39:40,780 contract with the Iridium to launch the 923 00:39:45,630 --> 00:39:43,450 graceful on together with five-year 924 00:39:49,170 --> 00:39:45,640 idiom next satellites on the spacings 925 00:39:51,240 --> 00:39:49,180 provided Feb 9 rocket so could you 926 00:39:57,780 --> 00:39:51,250 please start the videos to explain it a 927 00:40:01,220 --> 00:39:57,790 little bit so the launch site is fen 928 00:40:04,590 --> 00:40:01,230 Berk Air Force Base in California as 929 00:40:07,290 --> 00:40:04,600 mentioned before by frank webb the cont 930 00:40:10,260 --> 00:40:07,300 target launch date is May 19 931 00:40:13,230 --> 00:40:10,270 so 707 seconds after liftoff a 932 00:40:15,420 --> 00:40:13,240 separation system will fire Pyrus to 933 00:40:17,910 --> 00:40:15,430 deploy between graceful on satellites 934 00:40:19,150 --> 00:40:17,920 and then nearly the same nominal orbit 935 00:40:23,050 --> 00:40:19,160 at 490 936 00:40:25,150 --> 00:40:23,060 meters and 89 degrees inclination the 937 00:40:28,270 --> 00:40:25,160 separation empires as we push the truth 938 00:40:30,520 --> 00:40:28,280 spacecraft in opposite directions the 939 00:40:33,400 --> 00:40:30,530 fan Berg air force base will confirm a 940 00:40:37,240 --> 00:40:33,410 successful separation using downlink 941 00:40:41,790 --> 00:40:37,250 telemetry data from the upper stage so 942 00:40:44,770 --> 00:40:41,800 less than a minute later the boom that 943 00:40:47,710 --> 00:40:44,780 holds each satellites radio frequency 944 00:40:50,350 --> 00:40:47,720 s-band antenna it is deployed and the 945 00:40:53,140 --> 00:40:50,360 low rate radio transmitter is activated 946 00:40:56,710 --> 00:40:53,150 the first data from the spacecraft are 947 00:40:59,770 --> 00:40:56,720 expected about 23 minutes later to be 948 00:41:03,090 --> 00:40:59,780 received through the first pass of our 949 00:41:05,950 --> 00:41:03,100 NASA's tracking station at McMurdo at 950 00:41:06,910 --> 00:41:05,960 Antarctica and to talk about mission 951 00:41:12,910 --> 00:41:06,920 operations 952 00:41:15,580 --> 00:41:12,920 please start the next video so for this 953 00:41:18,250 --> 00:41:15,590 activities gf that has subcontracted 954 00:41:20,680 --> 00:41:18,260 force nominal mission lifetime or 5 955 00:41:24,120 --> 00:41:20,690 years with German space operation center 956 00:41:26,770 --> 00:41:24,130 of the German space agency s for grace 957 00:41:28,750 --> 00:41:26,780 the German Space Operations Center is 958 00:41:30,520 --> 00:41:28,760 providing the ground data system to 959 00:41:32,800 --> 00:41:30,530 monitor and control the satellites 960 00:41:35,620 --> 00:41:32,810 perform initial processing of a 961 00:41:37,360 --> 00:41:35,630 telemetry data and to deliver all the 962 00:41:40,000 --> 00:41:37,370 data to the science data system for 963 00:41:44,230 --> 00:41:40,010 further processing and generation of 964 00:41:45,640 --> 00:41:44,240 science products so Phil can you tell us 965 00:41:49,060 --> 00:41:45,650 a bit more about launch preparations 966 00:41:51,070 --> 00:41:49,070 right now at Vandenberg absolutely after 967 00:41:54,280 --> 00:41:51,080 we continued or finished up our 968 00:41:56,260 --> 00:41:54,290 environmental testing just outside of 969 00:41:59,910 --> 00:41:56,270 Munich at a test facility there called a 970 00:42:02,350 --> 00:41:59,920 ABG we loaded all of our equipment 971 00:42:06,910 --> 00:42:02,360 transported to Vandenberg Air Force Base 972 00:42:10,720 --> 00:42:06,920 have a video here shows the arrival when 973 00:42:14,440 --> 00:42:10,730 we landed we got help from the US Air 974 00:42:15,970 --> 00:42:14,450 Force to unload all of our equipment 975 00:42:19,870 --> 00:42:15,980 that equipment included the two 976 00:42:22,690 --> 00:42:19,880 satellites or our multi satellite launch 977 00:42:24,850 --> 00:42:22,700 dispenser all the ground support 978 00:42:27,670 --> 00:42:24,860 equipment we trucked everything over to 979 00:42:29,830 --> 00:42:27,680 a facility called astra tech and there 980 00:42:32,050 --> 00:42:29,840 we do a full check out 981 00:42:32,800 --> 00:42:32,060 completed a full check out of the two 982 00:42:34,000 --> 00:42:32,810 satellites 983 00:42:36,430 --> 00:42:34,010 sure everything survived the 984 00:42:39,580 --> 00:42:36,440 transportation and everything was 985 00:42:44,980 --> 00:42:39,590 working perfectly we fuel the satellites 986 00:42:49,300 --> 00:42:44,990 and then get them already mounted them 987 00:42:52,480 --> 00:42:49,310 on our launch dispenser and then we've 988 00:42:53,950 --> 00:42:52,490 transported the entire combination of 989 00:42:56,050 --> 00:42:53,960 the two satellites and the launch 990 00:43:00,520 --> 00:42:56,060 dispenser what we call the stack the 991 00:43:03,160 --> 00:43:00,530 grace fo stack over to SpaceX where 992 00:43:06,910 --> 00:43:03,170 we've been waiting to do integration 993 00:43:09,100 --> 00:43:06,920 with iridium and with SpaceX those 994 00:43:11,830 --> 00:43:09,110 activities are scheduled to start up 995 00:43:14,140 --> 00:43:11,840 this week come in the end of the week 996 00:43:16,840 --> 00:43:14,150 here so we're very excited about this 997 00:43:19,210 --> 00:43:16,850 and getting very close to launch it is 998 00:43:20,440 --> 00:43:19,220 exciting let's keep going what happens 999 00:43:25,750 --> 00:43:20,450 once it launches when can we expect 1000 00:43:29,320 --> 00:43:25,760 science so as Frank spoke of once we 1001 00:43:33,040 --> 00:43:29,330 finish that first pass over McMurdo we 1002 00:43:35,590 --> 00:43:33,050 start our 90 minute polar orbits the 1003 00:43:39,520 --> 00:43:35,600 earth is rotating underneath us we focus 1004 00:43:41,410 --> 00:43:39,530 the first few days with north polar and 1005 00:43:43,900 --> 00:43:41,420 south polar stations to get the maximum 1006 00:43:46,630 --> 00:43:43,910 amount of data that we can we do about 1007 00:43:48,490 --> 00:43:46,640 five days of checkout on all of the 1008 00:43:51,340 --> 00:43:48,500 avionics and the science instruments 1009 00:43:54,610 --> 00:43:51,350 themselves then we go into a 1010 00:43:56,260 --> 00:43:54,620 commissioning phase where we get the 1011 00:43:59,950 --> 00:43:56,270 instruments up and running we do 1012 00:44:03,100 --> 00:43:59,960 calibrations we verify our very first 1013 00:44:05,110 --> 00:44:03,110 gravity fields make sure the quality of 1014 00:44:07,660 --> 00:44:05,120 everything is working well do any 1015 00:44:10,450 --> 00:44:07,670 fine-tuning that we need and then we'll 1016 00:44:13,780 --> 00:44:10,460 go into our science operations phase at 1017 00:44:16,240 --> 00:44:13,790 about 90 days after launch fantastic 1018 00:44:18,370 --> 00:44:16,250 thank you so much to all of our experts 1019 00:44:20,680 --> 00:44:18,380 here today we are now ready to take some 1020 00:44:23,110 --> 00:44:20,690 more questions again if you are watching 1021 00:44:25,660 --> 00:44:23,120 on NASA TV you can ask a question via 1022 00:44:28,900 --> 00:44:25,670 social media with the hashtag ask NASA 1023 00:44:31,810 --> 00:44:28,910 and our first question will be from the 1024 00:44:34,630 --> 00:44:31,820 studio Paul verson from science again if 1025 00:44:36,310 --> 00:44:34,640 the laser ranging works as hoped what 1026 00:44:38,170 --> 00:44:36,320 types of mass changes might you be able 1027 00:44:42,160 --> 00:44:38,180 to detect that the original grace did 1028 00:44:45,090 --> 00:44:42,170 not that might be a good question for 1029 00:44:49,750 --> 00:44:45,100 Mike Hawkins to answer 1030 00:44:51,580 --> 00:44:49,760 I can take a crack at that so first of 1031 00:44:53,320 --> 00:44:51,590 all as Frank fleckner noted the laser is 1032 00:44:54,940 --> 00:44:53,330 kind of a demonstration that we can make 1033 00:44:57,100 --> 00:44:54,950 this kind of measurement it's a very 1034 00:44:58,510 --> 00:44:57,110 complicated measurement to make it's a 1035 00:44:59,800 --> 00:44:58,520 very precise measurement it's never been 1036 00:45:02,230 --> 00:44:59,810 done in space before between two 1037 00:45:04,120 --> 00:45:02,240 spacecraft from you know this precision 1038 00:45:05,620 --> 00:45:04,130 so we want to really just make sure we 1039 00:45:06,790 --> 00:45:05,630 can actually make this measurement and 1040 00:45:09,610 --> 00:45:06,800 that and that we understand the 1041 00:45:13,540 --> 00:45:09,620 measurement if it works it could be up 1042 00:45:14,740 --> 00:45:13,550 to several times better than a microwave 1043 00:45:16,150 --> 00:45:14,750 measurement in terms of accuracy it 1044 00:45:18,220 --> 00:45:16,160 could be as much as maybe 10 times 1045 00:45:19,540 --> 00:45:18,230 better or even even a little bit more 1046 00:45:22,360 --> 00:45:19,550 depending on exactly how the system 1047 00:45:24,100 --> 00:45:22,370 performs so if that continues to work we 1048 00:45:26,100 --> 00:45:24,110 will produce gravity fields from the 1049 00:45:28,450 --> 00:45:26,110 laser and from the microwave system 1050 00:45:29,980 --> 00:45:28,460 until the laser stops functioning so we 1051 00:45:31,990 --> 00:45:29,990 intend to actually go and produce those 1052 00:45:34,120 --> 00:45:32,000 science products if the system is all 1053 00:45:35,920 --> 00:45:34,130 working but the baseline for continuity 1054 00:45:37,840 --> 00:45:35,930 to continue the 15 years is really the 1055 00:45:39,070 --> 00:45:37,850 identical system for grace the micro 1056 00:45:40,900 --> 00:45:39,080 system but as long as the laser is 1057 00:45:44,860 --> 00:45:40,910 working well we will analyze those and 1058 00:45:46,930 --> 00:45:44,870 produce them but although the ranging 1059 00:45:49,360 --> 00:45:46,940 measurement is more accurate that the 1060 00:45:51,250 --> 00:45:49,370 the resolution of the physical 1061 00:45:53,290 --> 00:45:51,260 phenomenon the earth may not be anywhere 1062 00:45:55,600 --> 00:45:53,300 it's not a linear relationship so the 1063 00:45:57,160 --> 00:45:55,610 laser measurement is 2 times better you 1064 00:45:58,330 --> 00:45:57,170 might only get 10 percent better spatial 1065 00:45:59,830 --> 00:45:58,340 resolution because there's a lot of 1066 00:46:01,840 --> 00:45:59,840 other factors that go into it how the 1067 00:46:04,210 --> 00:46:01,850 drag is measured and and other other 1068 00:46:06,010 --> 00:46:04,220 technologies but if the laser successful 1069 00:46:08,590 --> 00:46:06,020 then that means future missions we could 1070 00:46:13,060 --> 00:46:08,600 we could we could have a more accurate 1071 00:46:15,150 --> 00:46:13,070 mission we have one more question from 1072 00:46:18,670 --> 00:46:15,160 the studio from the press 1073 00:46:20,140 --> 00:46:18,680 Randy Shostak again with EOS is the 1074 00:46:22,090 --> 00:46:20,150 addition of the laser ranging 1075 00:46:23,500 --> 00:46:22,100 interferometer the only significant 1076 00:46:26,530 --> 00:46:23,510 difference between Grace and the 1077 00:46:29,560 --> 00:46:26,540 follow-on I'll take a crack at that it 1078 00:46:32,440 --> 00:46:29,570 is a very significant difference to add 1079 00:46:35,220 --> 00:46:32,450 it but we also took advantage of lessons 1080 00:46:38,230 --> 00:46:35,230 learned from the grace mission and we 1081 00:46:39,550 --> 00:46:38,240 fine-tuned some of the construction 1082 00:46:42,520 --> 00:46:39,560 techniques that were used on the 1083 00:46:46,390 --> 00:46:42,530 spacecraft to eliminate noise background 1084 00:46:49,270 --> 00:46:46,400 noise and then of because of the 1085 00:46:52,000 --> 00:46:49,280 timeframe between Grace and grace 1086 00:46:55,090 --> 00:46:52,010 follow-on we've had to include more 1087 00:46:56,110 --> 00:46:55,100 advanced avionics and things so there 1088 00:46:58,160 --> 00:46:56,120 have been a number of improvements 1089 00:46:59,600 --> 00:46:58,170 inside this spacecraft 1090 00:47:01,190 --> 00:46:59,610 it was a real challenge to keep the 1091 00:47:03,830 --> 00:47:01,200 outside of the spacecraft looking very 1092 00:47:06,560 --> 00:47:03,840 much the same size as grace flying the 1093 00:47:09,290 --> 00:47:06,570 same way but inside we've made 1094 00:47:11,600 --> 00:47:09,300 adjustments as we needed to make sure 1095 00:47:14,900 --> 00:47:11,610 that we have a kind of mission that we 1096 00:47:15,950 --> 00:47:14,910 want we also have some questions from 1097 00:47:18,800 --> 00:47:15,960 social media 1098 00:47:20,750 --> 00:47:18,810 are you sure watching via space TV ask 1099 00:47:23,510 --> 00:47:20,760 why is Grace follow on the shape that it 1100 00:47:26,390 --> 00:47:23,520 is can you explain that for us sure I'll 1101 00:47:30,980 --> 00:47:26,400 take a crack at this the it's partly 1102 00:47:32,690 --> 00:47:30,990 it's the aerodynamics it's and it's a 1103 00:47:35,630 --> 00:47:32,700 combination of the aerodynamics of the 1104 00:47:37,280 --> 00:47:35,640 body which allow it to do the kind of 1105 00:47:40,940 --> 00:47:37,290 mission that we do without being 1106 00:47:44,930 --> 00:47:40,950 influenced too heavily by other effects 1107 00:47:48,320 --> 00:47:44,940 in space but also we have a very tightly 1108 00:47:50,510 --> 00:47:48,330 controlled thermal control system inside 1109 00:47:52,370 --> 00:47:50,520 and we monitor very closely and control 1110 00:47:55,460 --> 00:47:52,380 the temperature of all the elements 1111 00:47:58,250 --> 00:47:55,470 inside so that we make sure we don't 1112 00:48:00,500 --> 00:47:58,260 have any influence from flying in and 1113 00:48:02,270 --> 00:48:00,510 out of the Sun for instance that would 1114 00:48:08,510 --> 00:48:02,280 affect the gravity field measurement 1115 00:48:10,490 --> 00:48:08,520 itself there's so much excitement on 1116 00:48:12,650 --> 00:48:10,500 social media and related to this topic 1117 00:48:14,660 --> 00:48:12,660 on YouTube gunney asks will the grace 1118 00:48:19,490 --> 00:48:14,670 follow-on launch in deployment be shown 1119 00:48:22,940 --> 00:48:19,500 live and if so how can you watch it it 1120 00:48:26,150 --> 00:48:22,950 will be shown alive I think it'll be 1121 00:48:30,760 --> 00:48:26,160 Nassif gov slash NASA TV is definitely 1122 00:48:34,820 --> 00:48:33,080 great we have no more questions at this 1123 00:48:36,770 --> 00:48:34,830 point so that concludes our briefing for 1124 00:48:38,690 --> 00:48:36,780 today thanks to everyone who's been 1125 00:48:40,430 --> 00:48:38,700 watching if you'd like to learn more 1126 00:48:44,090 --> 00:48:40,440 about the grace follow-on mission go to 1127 00:48:46,010 --> 00:48:44,100 nasa.gov slash grace fo and don't miss