1 00:00:00,020 --> 00:00:29,300 [Music] 2 00:00:33,650 --> 00:00:31,670 welcome to Vandenberg Air Force Base in 3 00:00:35,660 --> 00:00:33,660 California and our pre-launch briefing 4 00:00:37,760 --> 00:00:35,670 for the grace follow-on mission I'm 5 00:00:40,430 --> 00:00:37,770 Steve Cole from NASA communications 6 00:00:42,080 --> 00:00:40,440 we're here today to tell you about the 7 00:00:44,230 --> 00:00:42,090 grace follow-on mission that stands for 8 00:00:46,820 --> 00:00:44,240 the Gravity Recovery and climate 9 00:00:49,040 --> 00:00:46,830 experiment mission follow-on because 10 00:00:51,740 --> 00:00:49,050 this is the second of the grace missions 11 00:00:52,160 --> 00:00:51,750 that we've flown we're all set to launch 12 00:00:54,880 --> 00:00:52,170 today 13 00:00:58,880 --> 00:00:54,890 I'm sorry launch tomorrow May 22nd at 14 00:01:00,979 --> 00:00:58,890 12:47 p.m. Pacific time we'll be sharing 15 00:01:03,009 --> 00:01:00,989 the ride into space with five iridium 16 00:01:06,710 --> 00:01:03,019 next communication satellites on a 17 00:01:08,870 --> 00:01:06,720 SpaceX Falcon 9 rocket grace follow-on 18 00:01:12,050 --> 00:01:08,880 is a joint mission between NASA and the 19 00:01:13,250 --> 00:01:12,060 German Research Center for geosciences 20 00:01:15,500 --> 00:01:13,260 or gfz 21 00:01:17,570 --> 00:01:15,510 we have five panelists for you today to 22 00:01:19,850 --> 00:01:17,580 tell you more about the mission so let 23 00:01:22,550 --> 00:01:19,860 me introduce you to them our first 24 00:01:24,649 --> 00:01:22,560 panelist will be David Jarrett grace 25 00:01:27,580 --> 00:01:24,659 follow-on program executive in the earth 26 00:01:30,380 --> 00:01:27,590 science division at NASA headquarters 27 00:01:32,030 --> 00:01:30,390 Frank Webb grace follow-on project 28 00:01:36,800 --> 00:01:32,040 scientist at NASA's Jet Propulsion 29 00:01:38,990 --> 00:01:36,810 Laboratory Frank fleckner grace 30 00:01:43,219 --> 00:01:39,000 follow-on project manager at the German 31 00:01:45,709 --> 00:01:43,229 Research Center for geosciences Phil 32 00:01:48,639 --> 00:01:45,719 Morton grace follow-on project manager 33 00:01:51,230 --> 00:01:48,649 at the Jet Propulsion Laboratory and 34 00:01:53,480 --> 00:01:51,240 finally captain Jennifer Hayden weather 35 00:01:56,569 --> 00:01:53,490 officer for the 30th Space Wing at 36 00:01:58,550 --> 00:01:56,579 Vandenberg after our presentations we'll 37 00:02:01,609 --> 00:01:58,560 have questions from the media both here 38 00:02:03,499 --> 00:02:01,619 in the auditorium on the phone lines and 39 00:02:05,480 --> 00:02:03,509 on social media if you're watching on 40 00:02:07,730 --> 00:02:05,490 NASA television you can ask a question 41 00:02:12,230 --> 00:02:07,740 with social media by using the hashtag 42 00:02:14,420 --> 00:02:12,240 ask NASA so we're ready to begin Dave 43 00:02:16,790 --> 00:02:14,430 over to you good morning and thank you 44 00:02:19,460 --> 00:02:16,800 for joining us we're very excited today 45 00:02:23,570 --> 00:02:19,470 to discuss the grace follow-on mission 46 00:02:25,940 --> 00:02:23,580 with you grace will continue the legacy 47 00:02:28,760 --> 00:02:25,950 of the original grace mission which 48 00:02:32,150 --> 00:02:28,770 ended just not long ago last year 49 00:02:35,140 --> 00:02:32,160 bringing us 15 years worth of exciting 50 00:02:39,020 --> 00:02:35,150 data and making many new discoveries 51 00:02:42,110 --> 00:02:39,030 NASA a science program studies earth as 52 00:02:43,550 --> 00:02:42,120 a complete system in this animation you 53 00:02:47,180 --> 00:02:43,560 can see that NASA 54 00:02:50,630 --> 00:02:47,190 currently has 17 satellites in orbit 55 00:02:54,500 --> 00:02:50,640 measuring everything from gases and 56 00:02:58,370 --> 00:02:54,510 clouds in the atmosphere to rainfall and 57 00:03:02,150 --> 00:02:58,380 soil moisture to land surface change and 58 00:03:04,370 --> 00:03:02,160 the water cycle grace fought tomorrow 59 00:03:07,040 --> 00:03:04,380 grace follow-on will be the two new kids 60 00:03:10,430 --> 00:03:07,050 on the block to continue to measure the 61 00:03:12,650 --> 00:03:10,440 mass of the Earth's mass mass changes of 62 00:03:15,710 --> 00:03:12,660 the Earth's system from the storage of 63 00:03:19,789 --> 00:03:15,720 water and aquifers to the changes in ice 64 00:03:21,590 --> 00:03:19,799 sheets and glaciers and without the help 65 00:03:24,970 --> 00:03:21,600 of our international partners the 66 00:03:31,160 --> 00:03:24,980 Germans we wouldn't be here today 67 00:03:35,930 --> 00:03:31,170 GF Zed is contributing the launch 68 00:03:39,710 --> 00:03:35,940 vehicle mission operations the laser ray 69 00:03:41,390 --> 00:03:39,720 laser radar reflectors and the optical 70 00:03:43,880 --> 00:03:41,400 components of the laser arranging 71 00:03:47,390 --> 00:03:43,890 interferometer technology development 72 00:03:50,060 --> 00:03:47,400 experiment NASA is providing the two 73 00:03:53,720 --> 00:03:50,070 satellites microwave instruments the 74 00:03:56,620 --> 00:03:53,730 accelerometers and the electronic 75 00:03:59,890 --> 00:03:56,630 components of the laser ranging 76 00:04:03,380 --> 00:03:59,900 interferometer this kind of cost-sharing 77 00:04:05,900 --> 00:04:03,390 brings more bang to the buck and euro in 78 00:04:09,710 --> 00:04:05,910 the case of grace follow-on to the 79 00:04:11,479 --> 00:04:09,720 American and German people as well as 80 00:04:14,080 --> 00:04:11,489 benefiting research from around 81 00:04:17,150 --> 00:04:14,090 researchers from around the world 82 00:04:19,670 --> 00:04:17,160 the next image shows NASA's current 83 00:04:21,529 --> 00:04:19,680 fleet with missions involving our 84 00:04:24,740 --> 00:04:21,539 international partners highlighted in 85 00:04:28,460 --> 00:04:24,750 red this type of collaboration is very 86 00:04:30,260 --> 00:04:28,470 important to us because we were able to 87 00:04:33,650 --> 00:04:30,270 share the cost of the missions and 88 00:04:36,860 --> 00:04:33,660 thereby enabling us to do a whole lot 89 00:04:40,070 --> 00:04:36,870 more for less it's a win-win situation 90 00:04:42,050 --> 00:04:40,080 for everyone because all countries 91 00:04:44,980 --> 00:04:42,060 benefit from the wealth of data that we 92 00:04:48,379 --> 00:04:44,990 gather about our Complex every 93 00:04:53,089 --> 00:04:48,389 ever-changing world and the impacts it 94 00:04:57,560 --> 00:04:55,159 grace follow-on is unique 95 00:05:01,760 --> 00:04:57,570 most of our satellites and 96 00:05:05,240 --> 00:05:01,770 use imagers that collect light reflected 97 00:05:07,790 --> 00:05:05,250 from the surface or the atmosphere grace 98 00:05:10,060 --> 00:05:07,800 follow-on for grace follow-on the 99 00:05:14,180 --> 00:05:10,070 instrument is really the two satellites 100 00:05:15,770 --> 00:05:14,190 together as a as a system the critical 101 00:05:19,070 --> 00:05:15,780 measurement that's made by grace 102 00:05:21,340 --> 00:05:19,080 follow-on is the very small changes in 103 00:05:24,320 --> 00:05:21,350 distance between the two satellites as 104 00:05:27,470 --> 00:05:24,330 they orbit the Earth and these changes 105 00:05:29,810 --> 00:05:27,480 are caused by the pull of gravity as it 106 00:05:33,800 --> 00:05:29,820 changes very minutely caused by 107 00:05:35,180 --> 00:05:33,810 different things and before we get into 108 00:05:37,250 --> 00:05:35,190 discussing exactly how those 109 00:05:39,650 --> 00:05:37,260 measurements are taken 110 00:05:42,350 --> 00:05:39,660 Frank Webb will describe the science of 111 00:05:46,700 --> 00:05:42,360 the mission and its impacts on our daily 112 00:05:48,710 --> 00:05:46,710 lives thanks Dave so I start out by 113 00:05:50,510 --> 00:05:48,720 saying just a little bit about the grace 114 00:05:52,550 --> 00:05:50,520 mission which were the following - so 115 00:05:55,100 --> 00:05:52,560 grace was really a revolutionary mission 116 00:05:57,920 --> 00:05:55,110 for us understanding the water cycle and 117 00:05:58,970 --> 00:05:57,930 how the climate behaves in the trends 118 00:06:03,380 --> 00:05:58,980 which were taking place over the last 119 00:06:05,720 --> 00:06:03,390 you know 10 or 15 years and it did this 120 00:06:07,760 --> 00:06:05,730 in a very unique way by you know making 121 00:06:09,290 --> 00:06:07,770 measurements of how the mask it's 122 00:06:11,180 --> 00:06:09,300 redistributed on the surface of the 123 00:06:13,700 --> 00:06:11,190 earth and these were this was a view 124 00:06:16,550 --> 00:06:13,710 that we didn't have before of the water 125 00:06:18,620 --> 00:06:16,560 on Earth we were able to see how water 126 00:06:20,420 --> 00:06:18,630 has moved from different parts of the 127 00:06:21,440 --> 00:06:20,430 earth by actually measuring its mass 128 00:06:23,060 --> 00:06:21,450 which is not something you see with your 129 00:06:24,410 --> 00:06:23,070 eyes something you you have to feel with 130 00:06:25,940 --> 00:06:24,420 this a light system and we'll hear a 131 00:06:28,340 --> 00:06:25,950 little bit more about that later so if 132 00:06:31,760 --> 00:06:28,350 we go to the first animation which shows 133 00:06:35,180 --> 00:06:31,770 some of the results from the 15 years of 134 00:06:39,440 --> 00:06:35,190 grace measurements this is a map of mass 135 00:06:41,510 --> 00:06:39,450 trends seen by Grace and you know as 136 00:06:42,980 --> 00:06:41,520 this animation goes forward there's it's 137 00:06:44,720 --> 00:06:42,990 pointing out several regions of the 138 00:06:46,730 --> 00:06:44,730 world both on the land and in the ocean 139 00:06:49,460 --> 00:06:46,740 and the ice sheets where with grace 140 00:06:52,700 --> 00:06:49,470 we're able to detect things like loss of 141 00:06:56,000 --> 00:06:52,710 a loss of ice mass from glaciers ice 142 00:06:59,300 --> 00:06:56,010 sheets Greenland places like that we 143 00:07:02,000 --> 00:06:59,310 only see storage of water on land areas 144 00:07:03,290 --> 00:07:02,010 where there is floods or or depletion of 145 00:07:04,970 --> 00:07:03,300 water on land where there's large 146 00:07:07,220 --> 00:07:04,980 aquifers and we've been pumping water 147 00:07:08,390 --> 00:07:07,230 out or there's been droughts where you 148 00:07:10,700 --> 00:07:08,400 have more water than has been 149 00:07:11,450 --> 00:07:10,710 accumulating we can also see from the 150 00:07:13,820 --> 00:07:11,460 grace data 151 00:07:16,219 --> 00:07:13,830 I'm still amount of mass actually went 152 00:07:17,629 --> 00:07:16,229 into the oceans you know not just 153 00:07:19,040 --> 00:07:17,639 measuring the sea low but yesterday's in 154 00:07:22,189 --> 00:07:19,050 mastering the ocean because sea level is 155 00:07:24,230 --> 00:07:22,199 a is a is a sea level rise it has 156 00:07:25,879 --> 00:07:24,240 basically two components its but it's 157 00:07:28,339 --> 00:07:25,889 the mass which goes into the ocean the 158 00:07:29,990 --> 00:07:28,349 volume change from that but also the 159 00:07:31,879 --> 00:07:30,000 volume change from thermal expansion of 160 00:07:33,499 --> 00:07:31,889 the water so there's those two things 161 00:07:36,230 --> 00:07:33,509 which actually total to make the whole 162 00:07:38,029 --> 00:07:36,240 sea level rise and by measuring with 163 00:07:40,189 --> 00:07:38,039 grace the mass change we actually 164 00:07:41,089 --> 00:07:40,199 measure how much of that is is water in 165 00:07:42,320 --> 00:07:41,099 the ocean how much is actually you know 166 00:07:43,610 --> 00:07:42,330 heating of the ocean and thermal 167 00:07:45,980 --> 00:07:43,620 expansion which is very important for 168 00:07:48,070 --> 00:07:45,990 understanding climate processes and 169 00:07:51,249 --> 00:07:48,080 predicting of the future of 170 00:07:53,749 --> 00:07:51,259 understanding how where they're headed 171 00:07:55,670 --> 00:07:53,759 so if you go to the the next animation 172 00:07:57,110 --> 00:07:55,680 I'll look in a little more detail for 173 00:08:00,170 --> 00:07:57,120 some of this the things shown on the 174 00:08:02,210 --> 00:08:00,180 previous chart and this just shows mass 175 00:08:03,439 --> 00:08:02,220 loss in Greenland so you can see on the 176 00:08:04,700 --> 00:08:03,449 left you can see Greenland on the right 177 00:08:06,800 --> 00:08:04,710 you can see what's the monthly 178 00:08:08,629 --> 00:08:06,810 measurements of mass change the monthly 179 00:08:10,700 --> 00:08:08,639 measure of water mass change or ice mass 180 00:08:12,260 --> 00:08:10,710 change in Greenland and you see you know 181 00:08:13,969 --> 00:08:12,270 there's a bit of a seasonal cycle there 182 00:08:15,980 --> 00:08:13,979 we see overall you know Greenland is 183 00:08:17,600 --> 00:08:15,990 actually losing has been losing mass 184 00:08:20,510 --> 00:08:17,610 over the last fifteen years and it's a 185 00:08:22,909 --> 00:08:20,520 little bit you know it's fairly linear 186 00:08:25,279 --> 00:08:22,919 it's about 281 Giga tons per year of 187 00:08:26,839 --> 00:08:25,289 mass loss and with the grace data we 188 00:08:27,560 --> 00:08:26,849 were able to see actually where that's 189 00:08:30,320 --> 00:08:27,570 coming from 190 00:08:31,580 --> 00:08:30,330 Greenland overall you can see that 191 00:08:33,469 --> 00:08:31,590 mostly in that in that figure it's 192 00:08:35,149 --> 00:08:33,479 coming from mostly the southern part of 193 00:08:37,279 --> 00:08:35,159 Greenland and that's led to other 194 00:08:39,409 --> 00:08:37,289 studies where we've looked at what we're 195 00:08:42,380 --> 00:08:39,419 looking at how or the influence of 196 00:08:43,550 --> 00:08:42,390 oceans in accelerating that mass loss of 197 00:08:45,620 --> 00:08:43,560 warming of the oceans around Greenland 198 00:08:47,329 --> 00:08:45,630 and how they you know you know interact 199 00:08:49,220 --> 00:08:47,339 with the ice or in the fioor the 200 00:08:52,130 --> 00:08:49,230 glaciers which pour into the into the 201 00:08:53,720 --> 00:08:52,140 seas so that's a very you know 202 00:08:55,850 --> 00:08:53,730 significant finding there and the amount 203 00:08:57,079 --> 00:08:55,860 of mass being lost as well as fact that 204 00:08:58,850 --> 00:08:57,089 mass was being lost when we first 205 00:09:01,250 --> 00:08:58,860 started grace you know it wasn't clear 206 00:09:03,079 --> 00:09:01,260 what the sign of the mass change in 207 00:09:05,360 --> 00:09:03,089 Greenland was was mass gaining ice or 208 00:09:06,980 --> 00:09:05,370 gaining no mass be any ice gain water 209 00:09:08,269 --> 00:09:06,990 gain snow or is it losing it but it's 210 00:09:10,880 --> 00:09:08,279 pretty clear from the 15 years of great 211 00:09:13,880 --> 00:09:10,890 data that it's been losing mass now if 212 00:09:15,829 --> 00:09:13,890 you start the next animation so in that 213 00:09:18,290 --> 00:09:15,839 animation I said we're it's losing 281 214 00:09:19,760 --> 00:09:18,300 Giga tons of water a year and this 215 00:09:21,530 --> 00:09:19,770 animation is just because a good ton is 216 00:09:24,090 --> 00:09:21,540 kind of a strange unit for people 217 00:09:25,949 --> 00:09:24,100 understand a Gaytan is a is a 218 00:09:28,710 --> 00:09:25,959 cube of water a kilometer on a side and 219 00:09:30,480 --> 00:09:28,720 this just shows it here in in in 220 00:09:32,850 --> 00:09:30,490 graphical form next to the Empire State 221 00:09:36,090 --> 00:09:32,860 Building just for reference that's you 222 00:09:38,040 --> 00:09:36,100 know 1,400 feet high or 0.4 you know 223 00:09:39,509 --> 00:09:38,050 kilometers high so that's you know 224 00:09:41,249 --> 00:09:39,519 that's what a Giga ton is and so 225 00:09:43,800 --> 00:09:41,259 Greenland loses two hundred eighty one 226 00:09:46,519 --> 00:09:43,810 of those a year if we go to the next 227 00:09:49,170 --> 00:09:46,529 animation this is a nation that is of 228 00:09:50,790 --> 00:09:49,180 Antarctica another another place where 229 00:09:52,740 --> 00:09:50,800 we have a large ice mass which is which 230 00:09:55,559 --> 00:09:52,750 is changing as climate is changing and 231 00:09:57,749 --> 00:09:55,569 evolving and this again you see you know 232 00:09:59,400 --> 00:09:57,759 the the loss of mass from Antarctica on 233 00:10:01,559 --> 00:09:59,410 the monthly scale you can see you know 234 00:10:03,509 --> 00:10:01,569 as it's every month is counting out from 235 00:10:05,160 --> 00:10:03,519 the grace data and you see in the colors 236 00:10:06,210 --> 00:10:05,170 you can see where it's being lost he's 237 00:10:07,740 --> 00:10:06,220 mostly being lost in the Western 238 00:10:11,400 --> 00:10:07,750 Antarctica that's a little bit of gain 239 00:10:13,769 --> 00:10:11,410 in Eastern Antarctica and and that that 240 00:10:15,660 --> 00:10:13,779 you know is you know interesting though 241 00:10:16,889 --> 00:10:15,670 overall from the standpoint of the mass 242 00:10:18,600 --> 00:10:16,899 balance of Antarctica they're not of 243 00:10:20,699 --> 00:10:18,610 water that's being an ice it's remaining 244 00:10:22,949 --> 00:10:20,709 at arctica and our cars losing more ice 245 00:10:24,840 --> 00:10:22,959 than it's gaining and and here it's a 246 00:10:28,170 --> 00:10:24,850 hundred and twenty Giga tons of water a 247 00:10:30,269 --> 00:10:28,180 year and you know combined Antarctica 248 00:10:33,389 --> 00:10:30,279 and Greenland account the amount of mass 249 00:10:35,900 --> 00:10:33,399 being lost that's about it's a four 250 00:10:38,069 --> 00:10:35,910 hundred and something Giga tons a year 251 00:10:40,199 --> 00:10:38,079 and that's equivalent to about a meet a 252 00:10:42,569 --> 00:10:40,209 millimeter or more of sea level rise per 253 00:10:45,569 --> 00:10:42,579 year just coming from those two ice ice 254 00:10:46,860 --> 00:10:45,579 masses and and and and this is something 255 00:10:48,509 --> 00:10:46,870 we that we've learned from from the 256 00:10:49,620 --> 00:10:48,519 great state of last fifteen years it's 257 00:10:51,090 --> 00:10:49,630 something that you know with grace 258 00:10:53,100 --> 00:10:51,100 falling we will be extending this data 259 00:10:54,929 --> 00:10:53,110 record so you better understand you know 260 00:10:56,639 --> 00:10:54,939 if these trends are continuing and 261 00:10:58,439 --> 00:10:56,649 better understand you know what the 262 00:10:59,610 --> 00:10:58,449 drivers of them are because it's very 263 00:11:02,220 --> 00:10:59,620 important for us to understand you know 264 00:11:03,870 --> 00:11:02,230 with the data we collect at NASA you 265 00:11:06,179 --> 00:11:03,880 know one of the weather more important 266 00:11:08,309 --> 00:11:06,189 things about the data for for society is 267 00:11:09,720 --> 00:11:08,319 that it helps inform us and help us 268 00:11:13,620 --> 00:11:09,730 understand these processes or make 269 00:11:16,290 --> 00:11:13,630 informed decisions the next animation so 270 00:11:18,509 --> 00:11:16,300 it's not just about ice or mass loss 271 00:11:20,009 --> 00:11:18,519 from that this is mass loss from you 272 00:11:21,269 --> 00:11:20,019 know water on the surface this is 273 00:11:23,429 --> 00:11:21,279 actually this is the navigation from 274 00:11:26,550 --> 00:11:23,439 western United States which shows a mass 275 00:11:28,980 --> 00:11:26,560 loss from from basically a large aquifer 276 00:11:30,600 --> 00:11:28,990 in this in central California so we use 277 00:11:33,210 --> 00:11:30,610 a lot of ground water in California and 278 00:11:35,269 --> 00:11:33,220 we had it we had a drought you know a 279 00:11:38,410 --> 00:11:35,279 few years ago and during that drought 280 00:11:40,690 --> 00:11:38,420 California loss wate water 281 00:11:42,700 --> 00:11:40,700 as farmers and agriculture pumped out 282 00:11:44,800 --> 00:11:42,710 more water to meet the needs that 283 00:11:47,260 --> 00:11:44,810 weren't being met by the snowpack in the 284 00:11:49,180 --> 00:11:47,270 mountains with a rainfall and with the 285 00:11:50,890 --> 00:11:49,190 grace data we could see clearly that you 286 00:11:52,420 --> 00:11:50,900 know it was losing weight and that was 287 00:11:54,910 --> 00:11:52,430 coming from this region of California 288 00:11:57,190 --> 00:11:54,920 where we have our large aquifer and into 289 00:11:59,500 --> 00:11:57,200 that series of grace measurements was 290 00:12:01,390 --> 00:11:59,510 from the end of the grace time series we 291 00:12:03,220 --> 00:12:01,400 had had a large rain storm and there was 292 00:12:05,680 --> 00:12:03,230 some recovery in the amount of mass 293 00:12:07,810 --> 00:12:05,690 amount of water in the ground it remains 294 00:12:10,900 --> 00:12:07,820 to be seen you know since you know grace 295 00:12:13,630 --> 00:12:10,910 ended in 2017 you know how that recovery 296 00:12:15,760 --> 00:12:13,640 you know goes forward but in a years in 297 00:12:17,590 --> 00:12:15,770 you know once grace launches tomorrow 298 00:12:18,910 --> 00:12:17,600 we'll have we'll start getting data and 299 00:12:21,160 --> 00:12:18,920 we'll have about a one-year gap we're 300 00:12:23,170 --> 00:12:21,170 able to see how much that water in that 301 00:12:24,970 --> 00:12:23,180 fell as a precipitation California 302 00:12:26,440 --> 00:12:24,980 actually stayed in the ground and went 303 00:12:27,730 --> 00:12:26,450 into storage or you know you can better 304 00:12:30,580 --> 00:12:27,740 understand how much you actually ran off 305 00:12:32,560 --> 00:12:30,590 and went into the oceans I wasn't more 306 00:12:35,650 --> 00:12:32,570 for us to understand the whole water 307 00:12:37,480 --> 00:12:35,660 process there and so you know that's 308 00:12:40,360 --> 00:12:37,490 just a little bit about the the the 309 00:12:43,090 --> 00:12:40,370 science of that we've learned from grace 310 00:12:44,560 --> 00:12:43,100 and this is science that we will be you 311 00:12:46,750 --> 00:12:44,570 know continuing with the grace follow-on 312 00:12:48,340 --> 00:12:46,760 and to better understand these trends 313 00:12:50,920 --> 00:12:48,350 understand if these trends are just 314 00:12:52,930 --> 00:12:50,930 short-term trends or more short-term 315 00:12:54,550 --> 00:12:52,940 variability and or longer term translate 316 00:12:56,260 --> 00:12:54,560 it's or you know our evolving climate 317 00:12:57,520 --> 00:12:56,270 and with that I'm going to head off to 318 00:12:59,020 --> 00:12:57,530 Frank who's gonna explain a little bit 319 00:13:02,770 --> 00:12:59,030 more about how the measurement actually 320 00:13:06,760 --> 00:13:02,780 works so Frank thanks so this I would 321 00:13:08,800 --> 00:13:06,770 shortly explain by an animation which 322 00:13:11,070 --> 00:13:08,810 shows you that grace follow-on is a 323 00:13:14,470 --> 00:13:11,080 constellation of two satellites 324 00:13:16,780 --> 00:13:14,480 separated by about 220 kilometres and 325 00:13:20,440 --> 00:13:16,790 the measurement of this inter-satellite 326 00:13:23,620 --> 00:13:20,450 range is the most critical data on grace 327 00:13:26,890 --> 00:13:23,630 and grace follow-on it is a function how 328 00:13:29,230 --> 00:13:26,900 the mass is distributed and on ground so 329 00:13:32,860 --> 00:13:29,240 if mass changes on ground like in 330 00:13:34,090 --> 00:13:32,870 aquifers or melting glaciers or in the 331 00:13:37,650 --> 00:13:34,100 oceans and so on 332 00:13:41,260 --> 00:13:37,660 you see it immediately in a range change 333 00:13:44,230 --> 00:13:41,270 which we measure very very precisely my 334 00:13:47,320 --> 00:13:44,240 microwave tracking system with a 335 00:13:49,630 --> 00:13:47,330 precision of about 1 micrometer that is 336 00:13:51,790 --> 00:13:49,640 about a tenth of human hair 337 00:13:55,960 --> 00:13:51,800 offers distance between Los Angeles and 338 00:13:58,390 --> 00:13:55,970 San Diego so this instrument is used as 339 00:14:00,910 --> 00:13:58,400 a let's say primary objective to 340 00:14:03,880 --> 00:14:00,920 continue the time series which we have 341 00:14:07,120 --> 00:14:03,890 started with grace and to continue with 342 00:14:10,720 --> 00:14:07,130 grace follow-on but we have also another 343 00:14:14,110 --> 00:14:10,730 secondary objective is graceful on which 344 00:14:16,420 --> 00:14:14,120 is explained on the next figure so to 345 00:14:20,530 --> 00:14:16,430 improve the spatial and the temporal 346 00:14:23,400 --> 00:14:20,540 resolution of our mass observations for 347 00:14:25,900 --> 00:14:23,410 Futura grace like missions we will fly a 348 00:14:29,820 --> 00:14:25,910 technology demonstrator called laser 349 00:14:34,510 --> 00:14:29,830 rangering interferometer so due to the 350 00:14:37,120 --> 00:14:34,520 shorter wavelengths of the laser ranging 351 00:14:39,760 --> 00:14:37,130 interferometer we will be able to 352 00:14:42,190 --> 00:14:39,770 observe a separation change at least a 353 00:14:45,450 --> 00:14:42,200 factor of 10 better than we do it with a 354 00:14:48,370 --> 00:14:45,460 microwave instrument which is a prime 355 00:14:50,740 --> 00:14:48,380 instrument on bot of grace follow-on and 356 00:14:53,560 --> 00:14:50,750 fillets arranging interferometer is 357 00:14:56,130 --> 00:14:53,570 really an excellent example of our great 358 00:14:59,940 --> 00:14:56,140 partnership between the US and Germany 359 00:15:03,370 --> 00:14:59,950 so for the Li is a cavity and the 360 00:15:06,220 --> 00:15:03,380 electronics are provided by our us 361 00:15:08,500 --> 00:15:06,230 partners and we in Germany have provided 362 00:15:11,320 --> 00:15:08,510 all the objects like the optical bench 363 00:15:14,680 --> 00:15:11,330 assembly a triple mirror assembly and 364 00:15:18,460 --> 00:15:14,690 others and the partners in Germany are 365 00:15:23,910 --> 00:15:18,470 the Albert Einstein Institute space Tech 366 00:15:26,140 --> 00:15:23,920 and DLR German Space Agency and we have 367 00:15:28,300 --> 00:15:26,150 implemented the laser ranging 368 00:15:31,630 --> 00:15:28,310 interferometer and a so-called racetrack 369 00:15:34,110 --> 00:15:31,640 confi configuration as you have seen the 370 00:15:38,710 --> 00:15:34,120 satellite was already filled by all the 371 00:15:41,560 --> 00:15:38,720 nominal instrumentation by the tanks in 372 00:15:43,930 --> 00:15:41,570 inside of a satellite so we had to 373 00:15:47,260 --> 00:15:43,940 choose a way how to route the laser beam 374 00:15:49,690 --> 00:15:47,270 inside of a satellite and for that the 375 00:15:52,960 --> 00:15:49,700 triple mirror assembly is most important 376 00:15:56,440 --> 00:15:52,970 to route it by 180 degrees back to the 377 00:15:59,710 --> 00:15:56,450 opposite satellite but we have also 378 00:16:02,440 --> 00:15:59,720 another secondary objective which is 379 00:16:05,860 --> 00:16:02,450 explained in the next video 380 00:16:07,900 --> 00:16:05,870 so here we use the so called radio or 381 00:16:09,850 --> 00:16:07,910 quotation principle which was first 382 00:16:13,810 --> 00:16:09,860 developed for the champ satellite 383 00:16:15,400 --> 00:16:13,820 launched in 2000 satellite launched by 384 00:16:20,590 --> 00:16:15,410 my Institute gfz 385 00:16:23,170 --> 00:16:20,600 and we have not only prime antenna on 386 00:16:25,840 --> 00:16:23,180 top of the satellites to perform the 387 00:16:28,090 --> 00:16:25,850 navigation of grace follow-on but we 388 00:16:31,329 --> 00:16:28,100 have also another second secondary 389 00:16:35,380 --> 00:16:31,339 antenna on the back side of each of 390 00:16:39,400 --> 00:16:35,390 these satellites which observe these 391 00:16:42,310 --> 00:16:39,410 signals between low altitude GPS 392 00:16:44,920 --> 00:16:42,320 satellite disappearing or coming up over 393 00:16:48,450 --> 00:16:44,930 the horizon of the earth and these 394 00:16:51,190 --> 00:16:48,460 signals are altered by refractive 395 00:16:54,340 --> 00:16:51,200 effects within the atmosphere and this 396 00:16:57,460 --> 00:16:54,350 we can observe and derive temperature 397 00:17:01,350 --> 00:16:57,470 and humidity profiles which we provide 398 00:17:05,439 --> 00:17:01,360 to the weather services on a 24/7 basis 399 00:17:07,270 --> 00:17:05,449 with a time delay of lessons we our so 400 00:17:12,520 --> 00:17:07,280 therefore we have installed a ground 401 00:17:17,230 --> 00:17:12,530 station in Spitsbergen on at the knee of 402 00:17:19,750 --> 00:17:17,240 the North Pole and use this station to 403 00:17:22,569 --> 00:17:19,760 fulfill the stringent requirements of 404 00:17:26,079 --> 00:17:22,579 the weather services we have another 405 00:17:29,040 --> 00:17:26,089 instrument onboard of graceful on and we 406 00:17:33,100 --> 00:17:29,050 added on on grace which is ELISA 407 00:17:36,030 --> 00:17:33,110 retroreflector provided by my Institute 408 00:17:39,070 --> 00:17:36,040 and we shoot from a network of about 409 00:17:42,040 --> 00:17:39,080 20-25 globally distributed ground 410 00:17:44,560 --> 00:17:42,050 stations you see an example the potsdam 411 00:17:47,710 --> 00:17:44,570 ground station by a laser - this laser 412 00:17:50,260 --> 00:17:47,720 little reflectors receives a beam back 413 00:17:53,470 --> 00:17:50,270 from the reflector and from the two-way 414 00:17:55,390 --> 00:17:53,480 travel time you can derive the orbit 415 00:17:57,520 --> 00:17:55,400 with millimeter precision and this 416 00:18:01,690 --> 00:17:57,530 Earth's one independent control of the 417 00:18:05,350 --> 00:18:01,700 GPS derived orbit of Grace and graceful 418 00:18:08,590 --> 00:18:05,360 on how mission operations will be 419 00:18:10,540 --> 00:18:08,600 performed after launch is shown in the 420 00:18:15,040 --> 00:18:10,550 next video 421 00:18:15,820 --> 00:18:15,050 gfz has subcontracted the Drummond space 422 00:18:19,120 --> 00:18:15,830 operation 423 00:18:21,070 --> 00:18:19,130 Center in Omaha often because they have 424 00:18:23,289 --> 00:18:21,080 a lot of experience from the grace 425 00:18:26,380 --> 00:18:23,299 mission they are running the Mission 426 00:18:29,080 --> 00:18:26,390 Control Center in Omaha often which you 427 00:18:31,299 --> 00:18:29,090 can see here in the video they operate 428 00:18:35,049 --> 00:18:31,309 two ground station in Vail Heim and 429 00:18:37,539 --> 00:18:35,059 noise trail it's and in which trail it's 430 00:18:39,669 --> 00:18:37,549 VI falls over raw data center which 431 00:18:42,490 --> 00:18:39,679 collects all the downlink data and 432 00:18:45,159 --> 00:18:42,500 provided service science data system for 433 00:18:47,200 --> 00:18:45,169 further processing and finally we will 434 00:18:50,350 --> 00:18:47,210 use the station which I have introduced 435 00:18:52,629 --> 00:18:50,360 with the radio or quotation for grace 436 00:18:55,149 --> 00:18:52,639 this is a primary downlink station on 437 00:18:58,750 --> 00:18:55,159 Spitsbergen so therefore we have now 438 00:19:01,600 --> 00:18:58,760 every orbit every 90 minutes telemetry 439 00:19:04,029 --> 00:19:01,610 data from the satellites which have 440 00:19:06,990 --> 00:19:04,039 helps to improve the tracking of the 441 00:19:10,120 --> 00:19:07,000 health status of grace follow-on and 442 00:19:12,820 --> 00:19:10,130 finally I would like to mention we are 443 00:19:16,389 --> 00:19:12,830 here for the launch it will be performed 444 00:19:18,190 --> 00:19:16,399 in 26 hours from now and therefore we 445 00:19:21,310 --> 00:19:18,200 have signed a contract or itray a 446 00:19:24,669 --> 00:19:21,320 contract with iridium which is shown 447 00:19:27,159 --> 00:19:24,679 here on the next video we will use a 448 00:19:31,720 --> 00:19:27,169 fake nine here from Vandenberg Air Force 449 00:19:34,210 --> 00:19:31,730 Base together with five you read your 450 00:19:37,029 --> 00:19:34,220 next satellites graceful on on top of 451 00:19:40,000 --> 00:19:37,039 this five we will be separated about 452 00:19:42,940 --> 00:19:40,010 eleven and a half minutes after launch 453 00:19:45,129 --> 00:19:42,950 and the two satellites will then be 454 00:19:49,870 --> 00:19:45,139 separated into two opposite directions 455 00:19:51,789 --> 00:19:49,880 and flying towards South owned medium 456 00:19:55,120 --> 00:19:51,799 village can device I gave them on mine 457 00:19:59,169 --> 00:19:55,130 point on partner Phil Martin sitting 458 00:20:01,060 --> 00:19:59,179 beside me thank you for a I'm going to 459 00:20:04,090 --> 00:20:01,070 give you a little more information about 460 00:20:06,549 --> 00:20:04,100 the satellites themselves we have to 461 00:20:09,009 --> 00:20:06,559 scale models here they are one-tenth 462 00:20:12,820 --> 00:20:09,019 scale so think of the actual satellite 463 00:20:15,190 --> 00:20:12,830 sizes about the size of a sports car as 464 00:20:17,289 --> 00:20:15,200 they mentioned before one in Los Angeles 465 00:20:20,950 --> 00:20:17,299 and one in San Diego that's how far 466 00:20:24,820 --> 00:20:20,960 apart they're flying and typically they 467 00:20:27,370 --> 00:20:24,830 have a unique shape we took great care 468 00:20:28,669 --> 00:20:27,380 to make sure that the satellite size and 469 00:20:30,289 --> 00:20:28,679 shape was identical to 470 00:20:31,940 --> 00:20:30,299 because we want to make sure that we 471 00:20:34,730 --> 00:20:31,950 have a continuity mission and that we 472 00:20:36,499 --> 00:20:34,740 try to do everything we can to collect 473 00:20:39,680 --> 00:20:36,509 the same kind of data that we took on 474 00:20:41,029 --> 00:20:39,690 Grace and there's some characteristics 475 00:20:43,940 --> 00:20:41,039 in the shape that help with the 476 00:20:45,769 --> 00:20:43,950 aerodynamics of they're orbiting we want 477 00:20:48,799 --> 00:20:45,779 to put the two satellites in orbit we 478 00:20:50,810 --> 00:20:48,809 want to do as little as possible to keep 479 00:20:53,090 --> 00:20:50,820 them perturbing them we let them float 480 00:20:55,159 --> 00:20:53,100 and we want them to react to the gravity 481 00:20:58,430 --> 00:20:55,169 field and the changes in mass and then 482 00:21:01,779 --> 00:20:58,440 measure those very fine fine finally 483 00:21:04,519 --> 00:21:01,789 precisely measured distances of a micron 484 00:21:09,230 --> 00:21:04,529 in order to do that the business end 485 00:21:12,200 --> 00:21:09,240 when in has the dual kak band microwave 486 00:21:13,759 --> 00:21:12,210 a signal that we use to is the primary 487 00:21:17,090 --> 00:21:13,769 instrument to measure this distance 488 00:21:19,820 --> 00:21:17,100 between the two satellites and then 489 00:21:24,049 --> 00:21:19,830 you'll see two ports here that these are 490 00:21:25,789 --> 00:21:24,059 the laser baffles and laser kind of 491 00:21:29,080 --> 00:21:25,799 think of it as a racetrack there's one 492 00:21:34,869 --> 00:21:29,090 laser that's a master that we cycle that 493 00:21:39,560 --> 00:21:37,639 the outside of the satellite was covered 494 00:21:43,549 --> 00:21:39,570 with solar arrays it's kind of a sleek 495 00:21:45,080 --> 00:21:43,559 look that this provides our power there 496 00:21:47,600 --> 00:21:45,090 are some cutouts here these are the 497 00:21:51,049 --> 00:21:47,610 stark camera baffles we use star cameras 498 00:21:53,749 --> 00:21:51,059 and a precision GPS antenna on top to 499 00:21:56,600 --> 00:21:53,759 map very precisely the location of these 500 00:21:59,389 --> 00:21:56,610 little changes and in the distance 501 00:22:00,889 --> 00:21:59,399 between the two spacecraft and then 502 00:22:02,659 --> 00:22:00,899 again as Frank mentioned on the back 503 00:22:05,210 --> 00:22:02,669 side of the spacecraft we have a radio 504 00:22:07,249 --> 00:22:05,220 occultation antenna and that's what we 505 00:22:09,350 --> 00:22:07,259 use to look at GPS signals moving 506 00:22:13,570 --> 00:22:09,360 through the atmosphere and use those to 507 00:22:16,460 --> 00:22:13,580 measure humidity in the atmosphere um 508 00:22:18,980 --> 00:22:16,470 and also underneath there's an S band 509 00:22:20,629 --> 00:22:18,990 boom when it's deployed it deploys early 510 00:22:22,850 --> 00:22:20,639 on in the mission and that's what we use 511 00:22:27,499 --> 00:22:22,860 for radio transmission to the ground 512 00:22:29,600 --> 00:22:27,509 stations I have a video here to kind of 513 00:22:31,519 --> 00:22:29,610 give you an idea of the inside of the 514 00:22:37,580 --> 00:22:31,529 spacecraft it was a it's it's quite 515 00:22:41,180 --> 00:22:37,590 compact but you can see as it was put 516 00:22:42,750 --> 00:22:41,190 together at Airbus it's quite 517 00:22:46,230 --> 00:22:42,760 complicated inside 518 00:22:49,710 --> 00:22:46,240 took essentially the grace design did 519 00:22:52,350 --> 00:22:49,720 upgrades for avionics and various bits 520 00:22:55,250 --> 00:22:52,360 of equipment that we could no longer get 521 00:22:59,190 --> 00:22:55,260 because of the 15 year lifetime which 522 00:23:00,960 --> 00:22:59,200 improved our avionics our electronics in 523 00:23:02,280 --> 00:23:00,970 the very heart of the spacecraft you can 524 00:23:04,350 --> 00:23:02,290 see in the video here is an 525 00:23:07,549 --> 00:23:04,360 accelerometer that's very sensitive we 526 00:23:11,400 --> 00:23:07,559 use that to remove gravitational effects 527 00:23:13,620 --> 00:23:11,410 and that piece of equipment is is 528 00:23:16,049 --> 00:23:13,630 aligned very precisely with the triple 529 00:23:18,870 --> 00:23:16,059 mirror assembly and the star cameras so 530 00:23:20,490 --> 00:23:18,880 that we make sure there's a particular 531 00:23:22,409 --> 00:23:20,500 reference for all the measurements that 532 00:23:25,080 --> 00:23:22,419 are made that's in the heart of the 533 00:23:26,940 --> 00:23:25,090 proof mass of the accelerometer so you 534 00:23:28,799 --> 00:23:26,950 can see that whole assembly being 535 00:23:30,630 --> 00:23:28,809 lowered into the middle of the 536 00:23:32,640 --> 00:23:30,640 spacecraft there it's kind of in the 537 00:23:35,070 --> 00:23:32,650 heart and the very center of mass of the 538 00:23:37,650 --> 00:23:35,080 spacecraft once we were done with 539 00:23:40,230 --> 00:23:37,660 environmental testing we transported all 540 00:23:43,220 --> 00:23:40,240 of our equipment the satellites out here 541 00:23:48,299 --> 00:23:43,230 demandin Berg this was sauced December 542 00:23:49,950 --> 00:23:48,309 and Air Force helped us unload and move 543 00:23:50,909 --> 00:23:49,960 all of our equipment it was quite a 544 00:23:53,789 --> 00:23:50,919 process 545 00:23:55,440 --> 00:23:53,799 we brought the two satellites or multi 546 00:23:57,960 --> 00:23:55,450 satellite dispenser and all of our 547 00:23:59,400 --> 00:23:57,970 ground support equipment we moved 548 00:24:03,000 --> 00:23:59,410 everything over to the Astrotech 549 00:24:06,049 --> 00:24:03,010 facility here did our functional checks 550 00:24:09,000 --> 00:24:06,059 are fueling of our nitrogen tanks 551 00:24:10,620 --> 00:24:09,010 battery charging and then we moved over 552 00:24:12,510 --> 00:24:10,630 to the Harris facility and you can see a 553 00:24:14,520 --> 00:24:12,520 time-lapse here of us lifting the 554 00:24:18,210 --> 00:24:14,530 satellites and putting them on the multi 555 00:24:20,880 --> 00:24:18,220 satellite dispenser so we had teams from 556 00:24:23,970 --> 00:24:20,890 Madrid Spain from Germany 557 00:24:26,909 --> 00:24:23,980 JPL all working together here to get 558 00:24:30,570 --> 00:24:26,919 these satellites put on the satellite 559 00:24:34,380 --> 00:24:30,580 dispenser properly mounted so that we 560 00:24:37,320 --> 00:24:34,390 can separate absolutely as we need to so 561 00:24:41,909 --> 00:24:37,330 it was quite a bit of work once we were 562 00:24:45,120 --> 00:24:41,919 done here at Harris we packed up that 563 00:24:48,150 --> 00:24:45,130 whole stack we call it the stack and we 564 00:24:49,560 --> 00:24:48,160 transported it over to SpaceX and when 565 00:24:52,770 --> 00:24:49,570 we started doing our integration 566 00:24:54,149 --> 00:24:52,780 activities with iridium I've got a 567 00:24:54,930 --> 00:24:54,159 couple of images here I'll just go 568 00:24:56,279 --> 00:24:54,940 through it just 569 00:24:59,219 --> 00:24:56,289 and give you an idea of the work that 570 00:25:02,450 --> 00:24:59,229 was done that was quite complicated and 571 00:25:04,710 --> 00:25:02,460 very interesting here you can see us 572 00:25:07,529 --> 00:25:04,720 removing the top of our shipping 573 00:25:09,779 --> 00:25:07,539 container the two spacecraft are mounted 574 00:25:11,509 --> 00:25:09,789 on the multi satellite dispenser but 575 00:25:16,560 --> 00:25:11,519 they're protected under a protective 576 00:25:19,169 --> 00:25:16,570 cover next image please you can see us 577 00:25:20,999 --> 00:25:19,179 now we've uncovered the satellites we 578 00:25:22,830 --> 00:25:21,009 made sure they're now they're stepping 579 00:25:26,489 --> 00:25:22,840 towards getting more and more flight 580 00:25:29,519 --> 00:25:26,499 ready as we remove protective covers we 581 00:25:31,889 --> 00:25:29,529 lift the whole assembly up and we mount 582 00:25:34,169 --> 00:25:31,899 the base of our multi satellite 583 00:25:37,409 --> 00:25:34,179 dispenser onto this adapter ring this 584 00:25:40,409 --> 00:25:37,419 was built by SpaceX to mate us directly 585 00:25:44,669 --> 00:25:40,419 along to the dispenser for the Iridium 586 00:25:47,820 --> 00:25:44,679 stack you go to the next picture you can 587 00:25:52,229 --> 00:25:47,830 see here below is the stack of five 588 00:25:55,859 --> 00:25:52,239 iridium satellites and we are lifting 589 00:25:58,139 --> 00:25:55,869 our stack assembly and then dropping it 590 00:26:01,349 --> 00:25:58,149 on top and then we will meet it to the 591 00:26:04,710 --> 00:26:01,359 top of the derivative stack the next 592 00:26:08,759 --> 00:26:04,720 image and again you can see here the 593 00:26:10,169 --> 00:26:08,769 combined set of payloads the Iridium 594 00:26:13,830 --> 00:26:10,179 stack on the bottom and the grace 595 00:26:15,450 --> 00:26:13,840 satellites on the top so this is a quite 596 00:26:18,149 --> 00:26:15,460 a spectacular view of what the 597 00:26:22,879 --> 00:26:18,159 satellites look like if you go to the 598 00:26:25,019 --> 00:26:22,889 next image this was a very interesting 599 00:26:28,080 --> 00:26:25,029 piece of procedure that we had to 600 00:26:31,499 --> 00:26:28,090 execute we lifted our stack and the 601 00:26:36,149 --> 00:26:31,509 Iridium stack together and then moved 602 00:26:39,389 --> 00:26:36,159 the whole thing over to this adapter the 603 00:26:42,560 --> 00:26:39,399 payload adaptor that is what mounts on 604 00:26:47,279 --> 00:26:42,570 the top of the second stage so you know 605 00:26:49,979 --> 00:26:47,289 an interesting very delicate and very 606 00:26:51,629 --> 00:26:49,989 precise movement of all the equipment to 607 00:26:52,019 --> 00:26:51,639 line it up and get it ready to go for 608 00:26:56,070 --> 00:26:52,029 launch 609 00:26:58,200 --> 00:26:56,080 next image and you'll see here the final 610 00:27:01,080 --> 00:26:58,210 stack as it is now the current status 611 00:27:02,249 --> 00:27:01,090 all of this now is encapsulated in the 612 00:27:05,039 --> 00:27:02,259 fairing 613 00:27:06,720 --> 00:27:05,049 we finished up that work end of last 614 00:27:09,900 --> 00:27:06,730 week and over the week 615 00:27:12,660 --> 00:27:09,910 the fairing now is is tipped 616 00:27:14,490 --> 00:27:12,670 horizontally and the whole assembly then 617 00:27:17,250 --> 00:27:14,500 mounted on the second stage of the 618 00:27:20,190 --> 00:27:17,260 rocket which is in the hangar over at 619 00:27:22,980 --> 00:27:20,200 SpaceX and should be rolling out this 620 00:27:25,560 --> 00:27:22,990 morning so we'll do our final testing 621 00:27:26,910 --> 00:27:25,570 over there today and and finish our 622 00:27:32,910 --> 00:27:26,920 checkouts and get ready for launch 623 00:27:34,530 --> 00:27:32,920 tomorrow so very exciting time a little 624 00:27:35,820 --> 00:27:34,540 to have another video here I just want 625 00:27:37,590 --> 00:27:35,830 to talk a little bit about what happens 626 00:27:39,510 --> 00:27:37,600 after separation give you an idea of 627 00:27:44,360 --> 00:27:39,520 what's going to happen right after we 628 00:27:48,060 --> 00:27:44,370 separate we come away from the dispenser 629 00:27:50,580 --> 00:27:48,070 about 50 seconds after we separate we 630 00:27:53,370 --> 00:27:50,590 have a boom deployment you see a little 631 00:27:56,340 --> 00:27:53,380 bit of an animation here of it and then 632 00:27:58,590 --> 00:27:56,350 about five minutes after that we start 633 00:28:01,530 --> 00:27:58,600 our attitude control system up we start 634 00:28:03,450 --> 00:28:01,540 pointing the s-band booms towards the 635 00:28:07,100 --> 00:28:03,460 earth we want them to fly in this kind 636 00:28:10,310 --> 00:28:07,110 of a configuration the spacecraft's 637 00:28:14,340 --> 00:28:10,320 spacecrafts aren't moving slowly apart 638 00:28:17,280 --> 00:28:14,350 and heading towards the South Pole takes 639 00:28:19,830 --> 00:28:17,290 about 23 minutes before we get to the 640 00:28:23,370 --> 00:28:19,840 first ground station which is McMurdo 641 00:28:26,310 --> 00:28:23,380 and Antarctica and when we pass over 642 00:28:28,550 --> 00:28:26,320 McMurdo we'll do a very quick check on 643 00:28:32,490 --> 00:28:28,560 both satellites to make sure we get 644 00:28:36,000 --> 00:28:32,500 telemetry do a dump of some data check 645 00:28:38,220 --> 00:28:36,010 on their health very quickly and we have 646 00:28:39,900 --> 00:28:38,230 every expectation of getting both 647 00:28:42,690 --> 00:28:39,910 satellites if for some reason we only 648 00:28:45,600 --> 00:28:42,700 get one in about 45 minutes later we 649 00:28:48,870 --> 00:28:45,610 come over another ground station that's 650 00:28:53,190 --> 00:28:48,880 all barred that's up toward the North 651 00:28:57,000 --> 00:28:53,200 Pole and then we have essentially or 652 00:28:58,860 --> 00:28:57,010 passes every orbit so that will continue 653 00:29:00,450 --> 00:28:58,870 to get more and more data and check on 654 00:29:04,550 --> 00:29:00,460 the health and we'll fire the spacecraft 655 00:29:06,960 --> 00:29:04,560 so we're all set all the ground stations 656 00:29:10,200 --> 00:29:06,970 ground ops that everything's ready to go 657 00:29:17,130 --> 00:29:10,210 for tomorrow so looking forward to the 658 00:29:18,840 --> 00:29:17,140 big day and captain Hayden thank you so 659 00:29:19,650 --> 00:29:18,850 I'll be going over and speaking to the 660 00:29:22,350 --> 00:29:19,660 weather and what 661 00:29:23,580 --> 00:29:22,360 expect tomorrow for day of launch for 662 00:29:25,260 --> 00:29:23,590 those who don't know here in central 663 00:29:27,960 --> 00:29:25,270 California and May we tend to see this 664 00:29:30,000 --> 00:29:27,970 daily pattern of fog and low Stratus in 665 00:29:32,190 --> 00:29:30,010 the morning we'll refer to as our marine 666 00:29:34,710 --> 00:29:32,200 layer and in the afternoon that breaks 667 00:29:36,930 --> 00:29:34,720 up gradually in the district us tier 668 00:29:38,340 --> 00:29:36,940 winds due to our sea breeze now 669 00:29:40,560 --> 00:29:38,350 currently however we're seeing a slight 670 00:29:42,300 --> 00:29:40,570 disruption to that typical pattern we 671 00:29:43,760 --> 00:29:42,310 have a late season low-pressure system 672 00:29:46,950 --> 00:29:43,770 that has moved in and really dug into 673 00:29:48,600 --> 00:29:46,960 Central and Southern California what 674 00:29:50,910 --> 00:29:48,610 this low-pressure system has done is 675 00:29:52,500 --> 00:29:50,920 simply thickened our marine layer up 676 00:29:54,930 --> 00:29:52,510 it'll make it a little bit more stubborn 677 00:29:56,580 --> 00:29:54,940 to burn off tomorrow and as yielded some 678 00:29:59,970 --> 00:29:56,590 drizzle this early this afternoon this 679 00:30:01,950 --> 00:29:59,980 morning as we look to the satellite we 680 00:30:03,510 --> 00:30:01,960 can see abundant low and mid-level 681 00:30:05,010 --> 00:30:03,520 clouds as they circulate 682 00:30:06,960 --> 00:30:05,020 counterclockwise around that 683 00:30:09,690 --> 00:30:06,970 low-pressure Center as it makes its way 684 00:30:11,310 --> 00:30:09,700 over California as this satellite 685 00:30:13,080 --> 00:30:11,320 imagery continues to loop you can see 686 00:30:16,650 --> 00:30:13,090 that these clouds will continue to push 687 00:30:18,330 --> 00:30:16,660 east as the day progresses what this 688 00:30:20,130 --> 00:30:18,340 means for tomorrow's forecast 689 00:30:22,320 --> 00:30:20,140 the high pressure won't quite have had 690 00:30:23,850 --> 00:30:22,330 time to build in just yet so our marine 691 00:30:25,230 --> 00:30:23,860 layer will continue to be elevated for 692 00:30:27,690 --> 00:30:25,240 launch day much like we're seeing this 693 00:30:30,840 --> 00:30:27,700 morning this will result in cloudy 694 00:30:33,870 --> 00:30:30,850 conditions at t0 from approximately 800 695 00:30:35,580 --> 00:30:33,880 to 1600 feet however visibility will be 696 00:30:38,280 --> 00:30:35,590 unrestricted which is good news for 697 00:30:41,670 --> 00:30:38,290 launch viewing and temperatures will be 698 00:30:43,920 --> 00:30:41,680 in the mid to high 50s surface winds 699 00:30:46,050 --> 00:30:43,930 will be slightly elevated out of the 700 00:30:48,180 --> 00:30:46,060 West at 8 to 12 knots which will drive 701 00:30:51,240 --> 00:30:48,190 our overall probability of violation for 702 00:30:52,770 --> 00:30:51,250 t0 to be less than 10% with that only 703 00:30:55,050 --> 00:30:52,780 constraint of concerned being ground 704 00:30:57,000 --> 00:30:55,060 winds what that means is that we're 705 00:30:58,650 --> 00:30:57,010 assessing a less than 10% chance that 706 00:31:01,740 --> 00:30:58,660 weather conditions will be a factor at 707 00:31:03,630 --> 00:31:01,750 takeoff as we move to the scrub day 708 00:31:05,340 --> 00:31:03,640 forecast the low will continue to shift 709 00:31:06,870 --> 00:31:05,350 further to the east and will finally 710 00:31:08,940 --> 00:31:06,880 allow our high pressure to settle back 711 00:31:10,850 --> 00:31:08,950 into place and return us to that more 712 00:31:12,870 --> 00:31:10,860 typical pattern as I mentioned earlier 713 00:31:14,790 --> 00:31:12,880 daytime heating will scatter out our 714 00:31:17,750 --> 00:31:14,800 marine layer and lead to just a few 715 00:31:19,800 --> 00:31:17,760 clouds and unrestricted visibility at t0 716 00:31:21,750 --> 00:31:19,810 temperatures will increase slightly as 717 00:31:23,970 --> 00:31:21,760 we get more heating in the day to the 718 00:31:26,430 --> 00:31:23,980 upper 50s to low 60s and winds will turn 719 00:31:29,040 --> 00:31:26,440 out of the west and decrease slightly to 720 00:31:32,150 --> 00:31:29,050 7 to 10 knots what this will do is drop 721 00:31:34,370 --> 00:31:32,160 our POV or probability of violation to 0 722 00:31:37,070 --> 00:31:34,380 for a scrub day we have no areas of 723 00:31:40,340 --> 00:31:37,080 concern for weather and that is all for 724 00:31:42,140 --> 00:31:40,350 weather back to you Steve okay thank you 725 00:31:44,660 --> 00:31:42,150 captain Hayden and to all our panelists 726 00:31:46,670 --> 00:31:44,670 we'll start with questions now as a 727 00:31:49,430 --> 00:31:46,680 reminder for those watching on NASA TV 728 00:31:53,000 --> 00:31:49,440 you can post a question to social media 729 00:31:54,590 --> 00:31:53,010 using the hashtag ask NASA and we have 730 00:31:57,740 --> 00:31:54,600 reporters in the room reporters on the 731 00:31:58,910 --> 00:31:57,750 phone line please if you're stating a 732 00:32:01,760 --> 00:31:58,920 question give us your name and 733 00:32:03,770 --> 00:32:01,770 affiliation I think we have some on 734 00:32:07,250 --> 00:32:03,780 social media so Katelyn we'll start with 735 00:32:08,930 --> 00:32:07,260 you sure Manisha on Twitter asks what 736 00:32:10,880 --> 00:32:08,940 type of research will be done from this 737 00:32:16,010 --> 00:32:10,890 mission and how would we benefit from it 738 00:32:19,000 --> 00:32:16,020 so I'll take that question so the top 739 00:32:22,010 --> 00:32:19,010 researcher be dumping this mission is is 740 00:32:25,070 --> 00:32:22,020 mostly related to climate and hydrology 741 00:32:27,050 --> 00:32:25,080 we'll be able to understand the trends 742 00:32:28,760 --> 00:32:27,060 that we've seen from grace how those 743 00:32:31,280 --> 00:32:28,770 trends are continuing and whether or not 744 00:32:32,780 --> 00:32:31,290 you know the factors which are driving 745 00:32:34,550 --> 00:32:32,790 those trends whether they're due to 746 00:32:36,620 --> 00:32:34,560 short-term variability or sort of longer 747 00:32:38,000 --> 00:32:36,630 term climate trends and that of course 748 00:32:39,800 --> 00:32:38,010 is very important for us to understand 749 00:32:42,740 --> 00:32:39,810 you know a number of things about the 750 00:32:44,150 --> 00:32:42,750 Earth System one one for example is just 751 00:32:47,240 --> 00:32:44,160 understanding how we manage our water 752 00:32:48,890 --> 00:32:47,250 resources because with grace we can 753 00:32:51,110 --> 00:32:48,900 grace and grace fall and we're able to 754 00:32:53,870 --> 00:32:51,120 see you know depletion of aquifers in 755 00:32:56,930 --> 00:32:53,880 the ground and in the rising of sea and 756 00:32:58,280 --> 00:32:56,940 in the in the addition of water mass to 757 00:33:00,020 --> 00:32:58,290 the oceans and those are very important 758 00:33:04,540 --> 00:33:00,030 for society because we're just trying to 759 00:33:10,490 --> 00:33:07,190 okay I guess we can keep going with 760 00:33:12,800 --> 00:33:10,500 social media questions planet by on 761 00:33:17,000 --> 00:33:12,810 Twitter asks how identical are the grace 762 00:33:19,940 --> 00:33:17,010 of Oh twins they are absolutely 763 00:33:21,500 --> 00:33:19,950 identical the only thing the only 764 00:33:23,600 --> 00:33:21,510 difference is they have an ID that 765 00:33:24,950 --> 00:33:23,610 separates them for our communications to 766 00:33:26,930 --> 00:33:24,960 the ground but we built them and took 767 00:33:34,880 --> 00:33:26,940 great care to make sure that they're 768 00:33:36,890 --> 00:33:34,890 absolutely identical hi Michael Baylor 769 00:33:39,770 --> 00:33:36,900 for NASA space flight I was wondering if 770 00:33:41,060 --> 00:33:39,780 the laser works as expected then it 771 00:33:43,580 --> 00:33:41,070 would be better than the microwave 772 00:33:45,260 --> 00:33:43,590 instrument I believe so well then that'd 773 00:33:48,020 --> 00:33:45,270 be used instead even though it's a 774 00:33:54,290 --> 00:33:48,030 secondary mission or we still use both 775 00:33:56,090 --> 00:33:54,300 how that work thank you we will of 776 00:33:58,130 --> 00:33:56,100 course rely first of all on the 777 00:34:00,080 --> 00:33:58,140 microwave instruments that's clear we 778 00:34:02,480 --> 00:34:00,090 want to follow on the mission it's a 779 00:34:04,160 --> 00:34:02,490 technology demonstrator we will try to 780 00:34:07,310 --> 00:34:04,170 switch on relays arranging 781 00:34:09,740 --> 00:34:07,320 interferometer quite soon and we can 782 00:34:12,260 --> 00:34:09,750 also operate both instruments in 783 00:34:15,740 --> 00:34:12,270 parallel so we will make inspections if 784 00:34:18,320 --> 00:34:15,750 you want of both instruments during our 785 00:34:20,360 --> 00:34:18,330 in orbit checkout face and so on and 786 00:34:24,350 --> 00:34:20,370 then we will see how it operates we can 787 00:34:26,390 --> 00:34:24,360 derive gravity fields from both kind of 788 00:34:28,040 --> 00:34:26,400 measurements and if he really would 789 00:34:30,320 --> 00:34:28,050 cease at release or arranging 790 00:34:34,280 --> 00:34:30,330 interferometer behaves as it was 791 00:34:35,630 --> 00:34:34,290 designed I would see there's no doubt to 792 00:34:39,440 --> 00:34:35,640 switch to the laser ranging 793 00:34:44,900 --> 00:34:39,450 interferometer that's clear okay we have 794 00:34:46,790 --> 00:34:44,910 a question here in the room a little 795 00:34:47,990 --> 00:34:46,800 more mundane question but are curious 796 00:34:50,720 --> 00:34:48,000 about the rideshare 797 00:34:52,340 --> 00:34:50,730 arrangement this isn't like you just 798 00:34:55,340 --> 00:34:52,350 stick out your thumb and hitch a ride on 799 00:34:59,000 --> 00:34:55,350 a rocket launch so who talks to who and 800 00:35:01,970 --> 00:34:59,010 how do you get together on this question 801 00:35:04,310 --> 00:35:01,980 to me so part of let's say our contract 802 00:35:07,850 --> 00:35:04,320 with NASA is that Germany is responsible 803 00:35:10,220 --> 00:35:07,860 for providing the launcher and we have 804 00:35:12,470 --> 00:35:10,230 sciences right ray our contract because 805 00:35:15,860 --> 00:35:12,480 it is part of the cost sharing between 806 00:35:16,740 --> 00:35:15,870 Germany and the US we also share our 807 00:35:19,890 --> 00:35:16,750 costs 808 00:35:22,790 --> 00:35:19,900 iridium it's of course nothing what 809 00:35:25,470 --> 00:35:22,800 happens every day but we have 810 00:35:28,110 --> 00:35:25,480 experienced a very very good partnership 811 00:35:30,180 --> 00:35:28,120 with iridium and SpaceX and we are 812 00:35:34,170 --> 00:35:30,190 totally confident that we have a 813 00:35:35,640 --> 00:35:34,180 successful launch tomorrow okay I think 814 00:35:38,820 --> 00:35:35,650 we have another question in the room 815 00:35:40,950 --> 00:35:38,830 right up front here I antthony why's Mad 816 00:35:43,050 --> 00:35:40,960 River Union I have two questions I read 817 00:35:44,850 --> 00:35:43,060 in the media pack that the satellites 818 00:35:46,650 --> 00:35:44,860 will change orientation a couple times 819 00:35:49,530 --> 00:35:46,660 through the mission and I was wondering 820 00:35:52,080 --> 00:35:49,540 about that and then why the solar panels 821 00:35:56,520 --> 00:35:52,090 have the little voids in them the little 822 00:36:00,330 --> 00:35:56,530 red marks on them yeah - so the first 823 00:36:03,840 --> 00:36:00,340 question when the spacecraft are moving 824 00:36:08,700 --> 00:36:03,850 in orbit one end of them is is mom 825 00:36:10,500 --> 00:36:08,710 bartered by atomic oxygen and so we it's 826 00:36:12,900 --> 00:36:10,510 this kind of a strategy of hours to 827 00:36:16,230 --> 00:36:12,910 reduce impacts to the end of the 828 00:36:18,420 --> 00:36:16,240 material on the end and so about halfway 829 00:36:20,430 --> 00:36:18,430 through the mission we will swap 830 00:36:21,930 --> 00:36:20,440 positions and so then the other 831 00:36:28,880 --> 00:36:21,940 satellite will take them take some of 832 00:36:31,290 --> 00:36:28,890 that the atomic oxygen impact and then 833 00:36:33,330 --> 00:36:31,300 depending on how long we go and we hope 834 00:36:36,690 --> 00:36:33,340 to go but longer than our five-year 835 00:36:40,410 --> 00:36:36,700 mission we'll work our strategy for the 836 00:36:42,840 --> 00:36:40,420 best times to do the exchange this is 837 00:36:44,280 --> 00:36:42,850 just a maneuver that we do similar to 838 00:36:45,990 --> 00:36:44,290 the maneuvers where we do 839 00:36:47,700 --> 00:36:46,000 station-keeping between the satellites 840 00:36:52,650 --> 00:36:47,710 and try and keep them about 220 841 00:36:54,450 --> 00:36:52,660 kilometers apart with respect to the 842 00:36:55,860 --> 00:36:54,460 voids in the solar arrays are you 843 00:36:59,190 --> 00:36:55,870 talking about these little tiny marks 844 00:37:03,470 --> 00:36:59,200 are you talking about these now this is 845 00:37:06,290 --> 00:37:03,480 just an interpretation on the model of 846 00:37:08,640 --> 00:37:06,300 how the solar panels are laid down 847 00:37:10,800 --> 00:37:08,650 there's a certain number of cells per 848 00:37:13,050 --> 00:37:10,810 string and so it's more of a 849 00:37:15,870 --> 00:37:13,060 manufacturing issue there's some gaps 850 00:37:17,520 --> 00:37:15,880 between some cell blocks as they're 851 00:37:21,810 --> 00:37:17,530 placed on the spacecraft and so it just 852 00:37:23,790 --> 00:37:21,820 it comes out not perfectly covered but 853 00:37:27,540 --> 00:37:23,800 again it's just been a matter of how 854 00:37:30,210 --> 00:37:27,550 it's laid down on the cells okay we have 855 00:37:32,160 --> 00:37:30,220 a question from the phone lines from 856 00:37:33,330 --> 00:37:32,170 porter at the verge go ahead please 857 00:37:36,930 --> 00:37:33,340 identify yourself 858 00:37:38,280 --> 00:37:36,940 hi this is Alison representative Virgil 859 00:37:40,740 --> 00:37:38,290 I was just wondering if one of us could 860 00:37:43,370 --> 00:37:40,750 explain how the decent change between 861 00:37:46,530 --> 00:37:43,380 the two satellites results in 862 00:37:54,530 --> 00:37:46,540 measurement of the mass change down on 863 00:37:58,339 --> 00:37:54,540 earth so we observe this distance 864 00:38:02,130 --> 00:37:58,349 measurements together with other 865 00:38:04,470 --> 00:38:02,140 observations which have been highlighted 866 00:38:06,390 --> 00:38:04,480 by a field for example from the 867 00:38:09,060 --> 00:38:06,400 accelerometer we measure all the 868 00:38:13,680 --> 00:38:09,070 non-gravitational measurements due to 869 00:38:16,710 --> 00:38:13,690 dry air drag or solar radiation and we 870 00:38:19,560 --> 00:38:16,720 invert all these measurements are doing 871 00:38:22,859 --> 00:38:19,570 orbit determination young we solve for 872 00:38:26,370 --> 00:38:22,869 large linear equation system with which 873 00:38:29,310 --> 00:38:26,380 it was about ten thousand unknowns there 874 00:38:32,670 --> 00:38:29,320 are over one months to solve for 875 00:38:37,260 --> 00:38:32,680 representation of the gravity field for 876 00:38:39,780 --> 00:38:37,270 one month okay we have another question 877 00:38:46,140 --> 00:38:39,790 on their phone lines from space like 878 00:38:49,170 --> 00:38:46,150 space flight now go ahead please 879 00:38:53,309 --> 00:38:49,180 I thanks for taking my call I did one of 880 00:38:54,779 --> 00:38:53,319 you please give me the target orbit when 881 00:38:58,230 --> 00:38:54,789 you separate from the talking nine you 882 00:38:59,549 --> 00:38:58,240 know Apogee Parrish inclination and is 883 00:39:01,289 --> 00:38:59,559 there any maneuvering the satellites 884 00:39:02,309 --> 00:39:01,299 have to do to reach their final clients 885 00:39:04,829 --> 00:39:02,319 orbit can you walk me through that 886 00:39:07,970 --> 00:39:04,839 commissioning and when you anticipate 887 00:39:11,490 --> 00:39:07,980 starting the science mission and 888 00:39:12,990 --> 00:39:11,500 secondly I could one of you provide the 889 00:39:15,870 --> 00:39:13,000 total cost of the grace follow-on 890 00:39:18,750 --> 00:39:15,880 mission with both the German and US 891 00:39:22,710 --> 00:39:18,760 contributions thank you I'll take the 892 00:39:28,440 --> 00:39:22,720 first part of that question we launch 893 00:39:30,720 --> 00:39:28,450 into 490 kilometres plus or minus 10 so 894 00:39:34,980 --> 00:39:30,730 we're approximately 500 kilometers in 895 00:39:37,799 --> 00:39:34,990 altitude at 89 degrees inclination when 896 00:39:40,440 --> 00:39:37,809 we separate were angled down at 30 897 00:39:42,269 --> 00:39:40,450 degrees so one comes off a little higher 898 00:39:45,890 --> 00:39:42,279 altitude one comes off a little lower 899 00:39:49,920 --> 00:39:45,900 this causes them to begin to drift apart 900 00:39:52,260 --> 00:39:49,930 and we are injecting directly towards 901 00:39:55,470 --> 00:39:52,270 the South Pole at 89 degrees so we don't 902 00:39:59,460 --> 00:39:55,480 do any particular maneuvering other than 903 00:40:02,970 --> 00:39:59,470 to get them in a safe state and get them 904 00:40:05,460 --> 00:40:02,980 nadir pointed on the bottom panel and 905 00:40:07,170 --> 00:40:05,470 then we let them naturally drift apart 906 00:40:08,609 --> 00:40:07,180 over a couple of days until they get 907 00:40:12,059 --> 00:40:08,619 about the right distance apart 908 00:40:14,579 --> 00:40:12,069 approximately 220 kilometers and this is 909 00:40:16,769 --> 00:40:14,589 a very kind of natural process and so we 910 00:40:21,750 --> 00:40:16,779 will just head toward the South Pole 911 00:40:22,859 --> 00:40:21,760 it's a fairly simple process that we go 912 00:40:25,740 --> 00:40:22,869 through we don't do any particular 913 00:40:29,069 --> 00:40:25,750 maneuver maneuvering other than when we 914 00:40:30,720 --> 00:40:29,079 reach our distance we do a station stop 915 00:40:33,839 --> 00:40:30,730 maneuver where we we slow things down 916 00:40:39,210 --> 00:40:33,849 and try and drift at around 220 917 00:40:41,579 --> 00:40:39,220 kilometers or the second part of that 918 00:40:43,920 --> 00:40:41,589 question the NASA contribution to this 919 00:40:47,069 --> 00:40:43,930 mission is approximately 430 million 920 00:40:48,800 --> 00:40:47,079 dollars and I'll let Frank answer the 921 00:40:52,850 --> 00:40:48,810 question for the German country 922 00:40:57,470 --> 00:40:52,860 I can answer that clearly it's about 77 923 00:41:00,890 --> 00:40:57,480 million euro for the German contributed 924 00:41:05,230 --> 00:41:00,900 items okay thank you I guess we have 925 00:41:09,170 --> 00:41:05,240 another let's see another question here 926 00:41:10,760 --> 00:41:09,180 how quickly the two great satellites 927 00:41:12,920 --> 00:41:10,770 have to get away from the Falcon nine 928 00:41:14,900 --> 00:41:12,930 second stage before I prefer performs 929 00:41:20,180 --> 00:41:14,910 the second burn for the Iridium 930 00:41:23,930 --> 00:41:20,190 satellites thank you don't look at the 931 00:41:25,640 --> 00:41:23,940 time line I think the the state I mean 932 00:41:27,530 --> 00:41:25,650 once we separate we start moving away 933 00:41:29,780 --> 00:41:27,540 and it's I think about two minutes but I 934 00:41:32,420 --> 00:41:29,790 have to check on that before they fire 935 00:41:35,360 --> 00:41:32,430 to move into their orbit that's 936 00:41:38,330 --> 00:41:35,370 something we'll have to check yeah we 937 00:41:39,830 --> 00:41:38,340 can get to that information we have 938 00:41:42,650 --> 00:41:39,840 another question on social media okay 939 00:41:45,050 --> 00:41:42,660 then on Twitter mari Takahashi from 940 00:41:47,300 --> 00:41:45,060 Smosh asks how soon will the data be 941 00:41:52,460 --> 00:41:47,310 collected and made available to the 942 00:41:54,260 --> 00:41:52,470 public I'll take that so the after after 943 00:41:55,910 --> 00:41:54,270 launch we have about a 90 day period of 944 00:41:56,720 --> 00:41:55,920 in orbit checkout and during that period 945 00:41:58,990 --> 00:41:56,730 we'll be collecting 946 00:42:01,670 --> 00:41:59,000 turnaround systems from instruments 947 00:42:05,300 --> 00:42:01,680 getting the spacecraft thermally stable 948 00:42:08,300 --> 00:42:05,310 I started collecting the first data it 949 00:42:10,850 --> 00:42:08,310 takes about 30 days of data to do one 950 00:42:13,640 --> 00:42:10,860 gravity field so during that 90-day 951 00:42:15,290 --> 00:42:13,650 period if all goes as expected we'll 952 00:42:18,380 --> 00:42:15,300 probably collect our first you know a 953 00:42:19,850 --> 00:42:18,390 couple of 30 day periods and then when 954 00:42:23,120 --> 00:42:19,860 we start generating gravity fields after 955 00:42:24,860 --> 00:42:23,130 that so expect you know the first source 956 00:42:28,070 --> 00:42:24,870 science fields to come you know 90 days 957 00:42:30,650 --> 00:42:28,080 or so after launch and then the the the 958 00:42:33,500 --> 00:42:30,660 goal is that have releases to you know 959 00:42:37,910 --> 00:42:33,510 the science community about 180 days 960 00:42:39,800 --> 00:42:37,920 after in order to check out gave me 961 00:42:42,800 --> 00:42:39,810 another question in the room the record 962 00:42:44,840 --> 00:42:42,810 matter of regaining newspaper for the 963 00:42:48,680 --> 00:42:44,850 original grace mission and the follow-on 964 00:42:50,090 --> 00:42:48,690 mission was we were you expecting the 965 00:42:52,480 --> 00:42:50,100 information that you got were you 966 00:42:54,760 --> 00:42:52,490 planning for this or were there any 967 00:42:56,960 --> 00:42:54,770 information there that was a surprise 968 00:42:58,220 --> 00:42:56,970 you know that you found particularly 969 00:43:00,770 --> 00:42:58,230 useful 970 00:43:03,320 --> 00:43:00,780 I like this question because I think 971 00:43:05,630 --> 00:43:03,330 because the original grace mission was 972 00:43:07,520 --> 00:43:05,640 was a competed mission to a NASA SSP 973 00:43:09,380 --> 00:43:07,530 program and it was a proposal that was 974 00:43:10,820 --> 00:43:09,390 ridden forth and people asked this 975 00:43:13,160 --> 00:43:10,830 question a lot of all sorts of prizes we 976 00:43:14,060 --> 00:43:13,170 had from from Grace and we actually have 977 00:43:16,910 --> 00:43:14,070 gone back and looked at the original 978 00:43:19,460 --> 00:43:16,920 proposal and almost all the things we 979 00:43:21,260 --> 00:43:19,470 saw with grace were were predicted to 980 00:43:23,330 --> 00:43:21,270 have to have been seen we didn't know 981 00:43:25,970 --> 00:43:23,340 how much we knew that the mission would 982 00:43:27,530 --> 00:43:25,980 be able to sense mass law you'd be able 983 00:43:29,030 --> 00:43:27,540 to detect mass loss from the ice sheets 984 00:43:31,370 --> 00:43:29,040 you know mass gained in the oceans 985 00:43:33,950 --> 00:43:31,380 underground ground ground water mass 986 00:43:36,740 --> 00:43:33,960 changes changes in the solid earth from 987 00:43:38,420 --> 00:43:36,750 large earthquakes and and I think almost 988 00:43:40,660 --> 00:43:38,430 all of these were predicting the 989 00:43:43,970 --> 00:43:40,670 proposals and were saying now the the 990 00:43:46,160 --> 00:43:43,980 the sort of you know the part that that 991 00:43:48,640 --> 00:43:46,170 wasn't in the proposal course was how 992 00:43:50,900 --> 00:43:48,650 much those changes were what they meant 993 00:43:52,250 --> 00:43:50,910 where they were occurring and how fast 994 00:43:54,680 --> 00:43:52,260 they were occurring and those were 995 00:43:57,590 --> 00:43:54,690 really the really revolutionary parts or 996 00:43:59,540 --> 00:43:57,600 results from the grace mission and you 997 00:44:01,850 --> 00:43:59,550 know we could see you know you can see 998 00:44:04,130 --> 00:44:01,860 for example you know ice sheets you know 999 00:44:05,450 --> 00:44:04,140 losing and losing ice and losing mass 1000 00:44:06,520 --> 00:44:05,460 and we could see it going into the 1001 00:44:08,900 --> 00:44:06,530 oceans and then we could actually 1002 00:44:11,510 --> 00:44:08,910 compare that with altimetry data and see 1003 00:44:13,310 --> 00:44:11,520 how much actual energy or expansion was 1004 00:44:14,660 --> 00:44:13,320 taking place in the oceans which is 1005 00:44:18,260 --> 00:44:14,670 something that you know we were not you 1006 00:44:21,410 --> 00:44:18,270 know able to see the discriminants 1007 00:44:24,770 --> 00:44:21,420 before also when there was a period in 1008 00:44:26,660 --> 00:44:24,780 2000 2011 when a sea-level sort of you 1009 00:44:27,890 --> 00:44:26,670 know slow see Oliver ice slow down slow 1010 00:44:29,150 --> 00:44:27,900 down a little bit and actually kind of 1011 00:44:32,240 --> 00:44:29,160 you know went the other direction very 1012 00:44:34,670 --> 00:44:32,250 briefly and from from the grace data one 1013 00:44:35,960 --> 00:44:34,680 could see or where we could see that you 1014 00:44:38,270 --> 00:44:35,970 know the ice sheets were still losing 1015 00:44:39,650 --> 00:44:38,280 ice at the same rate you know sea level 1016 00:44:41,690 --> 00:44:39,660 kind of slowed down rising a little bit 1017 00:44:43,820 --> 00:44:41,700 and that was also seen in the grace a 1018 00:44:45,590 --> 00:44:43,830 was that during that period there was 1019 00:44:47,720 --> 00:44:45,600 more water being stored on land there 1020 00:44:49,520 --> 00:44:47,730 was some heavier rain you know rainy 1021 00:44:51,140 --> 00:44:49,530 seasons in Australia and South America 1022 00:44:52,670 --> 00:44:51,150 and that that sort of equivalent of mass 1023 00:44:54,710 --> 00:44:52,680 was actually going to storage on land 1024 00:44:56,060 --> 00:44:54,720 very briefly instead of going into the 1025 00:44:57,410 --> 00:44:56,070 oceans and it was eventually you know at 1026 00:45:01,300 --> 00:44:57,420 least in the oceans and you know the 1027 00:45:03,350 --> 00:45:01,310 rate of civil rights you know continued 1028 00:45:06,380 --> 00:45:03,360 okay I think we have some additional 1029 00:45:08,930 --> 00:45:06,390 questions on social media katelyn from 1030 00:45:11,210 --> 00:45:08,940 twitter ivan corona of AFP asks what 1031 00:45:11,990 --> 00:45:11,220 other kinds of mass besides water may be 1032 00:45:14,180 --> 00:45:12,000 protected 1033 00:45:17,930 --> 00:45:14,190 may be detected by grace fo satellites 1034 00:45:20,090 --> 00:45:17,940 so I think so so the satellites are you 1035 00:45:22,400 --> 00:45:20,100 know the detect are since it all mass 1036 00:45:25,700 --> 00:45:22,410 change around around around the globe 1037 00:45:26,360 --> 00:45:25,710 and then we make measurements every 30 1038 00:45:29,210 --> 00:45:26,370 days 1039 00:45:31,520 --> 00:45:29,220 and so we see atmospheric ocean tides 1040 00:45:34,910 --> 00:45:31,530 you know solid earth changes you know 1041 00:45:36,380 --> 00:45:34,920 water ice you know moving around on the 1042 00:45:37,700 --> 00:45:36,390 30-day time scale there are a lot of 1043 00:45:39,020 --> 00:45:37,710 things which don't change very rapidly 1044 00:45:40,250 --> 00:45:39,030 and then you know solid earth is 1045 00:45:43,040 --> 00:45:40,260 changing rapidly on us we have an 1046 00:45:45,830 --> 00:45:43,050 earthquake and for atmospheric mass 1047 00:45:47,210 --> 00:45:45,840 changes we we tend to to calibrate that 1048 00:45:49,760 --> 00:45:47,220 out because we want to see sort of you 1049 00:45:51,440 --> 00:45:49,770 know sort of water so we have some 1050 00:45:54,080 --> 00:45:51,450 models based on atmospheric models yeah 1051 00:45:55,280 --> 00:45:54,090 how much mass is in the atmosphere so we 1052 00:45:57,260 --> 00:45:55,290 can calibrate that and really get down 1053 00:46:00,530 --> 00:45:57,270 to sort of you know mass change from 1054 00:46:02,180 --> 00:46:00,540 water in the ground in the surface in 1055 00:46:07,640 --> 00:46:02,190 source material in the oceans in the ice 1056 00:46:09,200 --> 00:46:07,650 sheets okay if we let's see do we have 1057 00:46:11,690 --> 00:46:09,210 any other additional questions here in 1058 00:46:13,010 --> 00:46:11,700 the room on social media okay well with 1059 00:46:14,960 --> 00:46:13,020 no further questions that'll end our 1060 00:46:17,630 --> 00:46:14,970 briefing for today just want to remind 1061 00:46:21,020 --> 00:46:17,640 everyone to tune into our live launch 1062 00:46:23,660 --> 00:46:21,030 broadcast starts tomorrow at 12:15 1063 00:46:26,330 --> 00:46:23,670 Pacific 3:15 Eastern and you can also 1064 00:46:30,590 --> 00:46:26,340 follow along on the launch blog which is 1065 00:46:31,850 --> 00:46:30,600 online at nasa.gov slash grace fo where 1066 00:46:34,010 --> 00:46:31,860 you can find a lot more information 1067 00:46:36,470 --> 00:46:34,020 about this unique and important mission