1 00:00:32,680 --> 00:00:35,110 when ancient man looked to the heavens 2 00:00:35,110 --> 00:00:35,120 when ancient man looked to the heavens 3 00:00:35,120 --> 00:00:37,209 when ancient man looked to the heavens for guidance from the gods 4 00:00:37,209 --> 00:00:37,219 for guidance from the gods 5 00:00:37,219 --> 00:00:40,270 for guidance from the gods he noticed star patterns and began to 6 00:00:40,270 --> 00:00:40,280 he noticed star patterns and began to 7 00:00:40,280 --> 00:00:42,100 he noticed star patterns and began to document their movement across the 8 00:00:42,100 --> 00:00:42,110 document their movement across the 9 00:00:42,110 --> 00:00:44,950 document their movement across the heavens the ancients believed that the 10 00:00:44,950 --> 00:00:44,960 heavens the ancients believed that the 11 00:00:44,960 --> 00:00:48,340 heavens the ancients believed that the earth was flat but around 350 BC 12 00:00:48,340 --> 00:00:48,350 earth was flat but around 350 BC 13 00:00:48,350 --> 00:00:50,410 earth was flat but around 350 BC Aristotle proved that the earth was 14 00:00:50,410 --> 00:00:50,420 Aristotle proved that the earth was 15 00:00:50,420 --> 00:00:56,500 Aristotle proved that the earth was round later about 150 AD Ptolemy 16 00:00:56,500 --> 00:00:56,510 round later about 150 AD Ptolemy 17 00:00:56,510 --> 00:00:59,049 round later about 150 AD Ptolemy presented the geocentric theory the 18 00:00:59,049 --> 00:00:59,059 presented the geocentric theory the 19 00:00:59,059 --> 00:01:01,060 presented the geocentric theory the belief that the earth is stationary at 20 00:01:01,060 --> 00:01:01,070 belief that the earth is stationary at 21 00:01:01,070 --> 00:01:03,460 belief that the earth is stationary at the center of the universe with the Sun 22 00:01:03,460 --> 00:01:03,470 the center of the universe with the Sun 23 00:01:03,470 --> 00:01:06,550 the center of the universe with the Sun Moon stars and planets revolving around 24 00:01:06,550 --> 00:01:06,560 Moon stars and planets revolving around 25 00:01:06,560 --> 00:01:12,910 Moon stars and planets revolving around it in complex orbits in the 1500s 26 00:01:12,910 --> 00:01:12,920 it in complex orbits in the 1500s 27 00:01:12,920 --> 00:01:15,640 it in complex orbits in the 1500s Nicholas Copernicus of Poland presented 28 00:01:15,640 --> 00:01:15,650 Nicholas Copernicus of Poland presented 29 00:01:15,650 --> 00:01:18,160 Nicholas Copernicus of Poland presented the heliocentric theory the belief that 30 00:01:18,160 --> 00:01:18,170 the heliocentric theory the belief that 31 00:01:18,170 --> 00:01:21,100 the heliocentric theory the belief that the Earth revolves around the Sun as it 32 00:01:21,100 --> 00:01:21,110 the Earth revolves around the Sun as it 33 00:01:21,110 --> 00:01:24,460 the Earth revolves around the Sun as it rotates on its axis this aspect of 34 00:01:24,460 --> 00:01:24,470 rotates on its axis this aspect of 35 00:01:24,470 --> 00:01:26,649 rotates on its axis this aspect of astronomy evolved into an intricate 36 00:01:26,649 --> 00:01:26,659 astronomy evolved into an intricate 37 00:01:26,659 --> 00:01:29,350 astronomy evolved into an intricate study of planetary motion known as 38 00:01:29,350 --> 00:01:29,360 study of planetary motion known as 39 00:01:29,360 --> 00:01:33,760 study of planetary motion known as orbital mechanics 40 00:01:33,760 --> 00:01:33,770 41 00:01:33,770 --> 00:01:36,789 today orbital mechanics is applied to 42 00:01:36,789 --> 00:01:36,799 today orbital mechanics is applied to 43 00:01:36,799 --> 00:01:39,219 today orbital mechanics is applied to spaceflight and satellites that orbit 44 00:01:39,219 --> 00:01:39,229 spaceflight and satellites that orbit 45 00:01:39,229 --> 00:01:41,740 spaceflight and satellites that orbit the Earth or travel beyond our solar 46 00:01:41,740 --> 00:01:41,750 the Earth or travel beyond our solar 47 00:01:41,750 --> 00:02:05,260 the Earth or travel beyond our solar system 48 00:02:05,260 --> 00:02:05,270 49 00:02:05,270 --> 00:02:10,130 in the early 1600s Johann Kepler a 50 00:02:10,130 --> 00:02:10,140 in the early 1600s Johann Kepler a 51 00:02:10,140 --> 00:02:12,860 in the early 1600s Johann Kepler a German mathematician using the data on 52 00:02:12,860 --> 00:02:12,870 German mathematician using the data on 53 00:02:12,870 --> 00:02:15,170 German mathematician using the data on planetary observations collected by the 54 00:02:15,170 --> 00:02:15,180 planetary observations collected by the 55 00:02:15,180 --> 00:02:17,570 planetary observations collected by the Danish scientist Tycho Brahe he 56 00:02:17,570 --> 00:02:17,580 Danish scientist Tycho Brahe he 57 00:02:17,580 --> 00:02:22,040 Danish scientist Tycho Brahe he developed three laws of planetary motion 58 00:02:22,040 --> 00:02:22,050 developed three laws of planetary motion 59 00:02:22,050 --> 00:02:25,850 developed three laws of planetary motion Kepler's first law states all planets 60 00:02:25,850 --> 00:02:25,860 Kepler's first law states all planets 61 00:02:25,860 --> 00:02:28,820 Kepler's first law states all planets move in ellipses or 'but there's a Sun 62 00:02:28,820 --> 00:02:28,830 move in ellipses or 'but there's a Sun 63 00:02:28,830 --> 00:02:36,100 move in ellipses or 'but there's a Sun at one focus and the other focus empty 64 00:02:36,100 --> 00:02:36,110 65 00:02:36,110 --> 00:02:39,290 applied to earth satellites the center 66 00:02:39,290 --> 00:02:39,300 applied to earth satellites the center 67 00:02:39,300 --> 00:02:42,500 applied to earth satellites the center of the earth becomes one focus with the 68 00:02:42,500 --> 00:02:42,510 of the earth becomes one focus with the 69 00:02:42,510 --> 00:02:48,050 of the earth becomes one focus with the other focus empty for circular orbits 70 00:02:48,050 --> 00:02:48,060 other focus empty for circular orbits 71 00:02:48,060 --> 00:02:57,050 other focus empty for circular orbits the two foci coincide Kepler's second 72 00:02:57,050 --> 00:02:57,060 the two foci coincide Kepler's second 73 00:02:57,060 --> 00:03:00,440 the two foci coincide Kepler's second law the law of areas states the line 74 00:03:00,440 --> 00:03:00,450 law the law of areas states the line 75 00:03:00,450 --> 00:03:03,440 law the law of areas states the line joining the planet to the Sun sweeps 76 00:03:03,440 --> 00:03:03,450 joining the planet to the Sun sweeps 77 00:03:03,450 --> 00:03:08,160 joining the planet to the Sun sweeps over equal areas in equal time intervals 78 00:03:08,160 --> 00:03:08,170 over equal areas in equal time intervals 79 00:03:08,170 --> 00:03:11,490 over equal areas in equal time intervals when a satellite orbits the line joining 80 00:03:11,490 --> 00:03:11,500 when a satellite orbits the line joining 81 00:03:11,500 --> 00:03:14,460 when a satellite orbits the line joining it to the earth sweeps over equal areas 82 00:03:14,460 --> 00:03:14,470 it to the earth sweeps over equal areas 83 00:03:14,470 --> 00:03:18,510 it to the earth sweeps over equal areas in equal periods of time if areas one 84 00:03:18,510 --> 00:03:18,520 in equal periods of time if areas one 85 00:03:18,520 --> 00:03:22,260 in equal periods of time if areas one two and three are equal times 1 2 & 3 86 00:03:22,260 --> 00:03:22,270 two and three are equal times 1 2 & 3 87 00:03:22,270 --> 00:03:25,920 two and three are equal times 1 2 & 3 are also equal therefore the speed of 88 00:03:25,920 --> 00:03:25,930 are also equal therefore the speed of 89 00:03:25,930 --> 00:03:28,260 are also equal therefore the speed of the satellite changes depending on its 90 00:03:28,260 --> 00:03:28,270 the satellite changes depending on its 91 00:03:28,270 --> 00:03:34,280 the satellite changes depending on its distance from the center of the earth 92 00:03:34,280 --> 00:03:34,290 93 00:03:34,290 --> 00:03:37,530 speed is greatest at the point in the 94 00:03:37,530 --> 00:03:37,540 speed is greatest at the point in the 95 00:03:37,540 --> 00:03:39,750 speed is greatest at the point in the orbit closest to the earth called 96 00:03:39,750 --> 00:03:39,760 orbit closest to the earth called 97 00:03:39,760 --> 00:03:42,990 orbit closest to the earth called perigee and is slowest at the point 98 00:03:42,990 --> 00:03:43,000 perigee and is slowest at the point 99 00:03:43,000 --> 00:03:51,610 perigee and is slowest at the point farthest from the earth called Apogee 100 00:03:51,610 --> 00:03:51,620 101 00:03:51,620 --> 00:03:54,920 it is important to note that the orbit 102 00:03:54,920 --> 00:03:54,930 it is important to note that the orbit 103 00:03:54,930 --> 00:03:57,470 it is important to note that the orbit followed by a satellite is not dependent 104 00:03:57,470 --> 00:03:57,480 followed by a satellite is not dependent 105 00:03:57,480 --> 00:04:01,520 followed by a satellite is not dependent on its mass a large heavy satellite 106 00:04:01,520 --> 00:04:01,530 on its mass a large heavy satellite 107 00:04:01,530 --> 00:04:04,010 on its mass a large heavy satellite could be in the same orbit with a small 108 00:04:04,010 --> 00:04:04,020 could be in the same orbit with a small 109 00:04:04,020 --> 00:04:07,310 could be in the same orbit with a small light one each sweeping out equal areas 110 00:04:07,310 --> 00:04:07,320 light one each sweeping out equal areas 111 00:04:07,320 --> 00:04:12,050 light one each sweeping out equal areas in equal periods of time Kepler's third 112 00:04:12,050 --> 00:04:12,060 in equal periods of time Kepler's third 113 00:04:12,060 --> 00:04:15,230 in equal periods of time Kepler's third law the law of periods relates the time 114 00:04:15,230 --> 00:04:15,240 law the law of periods relates the time 115 00:04:15,240 --> 00:04:17,300 law the law of periods relates the time required for a planet to make one 116 00:04:17,300 --> 00:04:17,310 required for a planet to make one 117 00:04:17,310 --> 00:04:20,120 required for a planet to make one complete trip around the Sun to its mean 118 00:04:20,120 --> 00:04:20,130 complete trip around the Sun to its mean 119 00:04:20,130 --> 00:04:24,050 complete trip around the Sun to its mean distance from the Sun for any planet the 120 00:04:24,050 --> 00:04:24,060 distance from the Sun for any planet the 121 00:04:24,060 --> 00:04:26,720 distance from the Sun for any planet the square of its period of revolution is 122 00:04:26,720 --> 00:04:26,730 square of its period of revolution is 123 00:04:26,730 --> 00:04:29,750 square of its period of revolution is directly proportional to the cube of its 124 00:04:29,750 --> 00:04:29,760 directly proportional to the cube of its 125 00:04:29,760 --> 00:04:37,430 directly proportional to the cube of its mean distance from the Sun applied to 126 00:04:37,430 --> 00:04:37,440 mean distance from the Sun applied to 127 00:04:37,440 --> 00:04:39,410 mean distance from the Sun applied to earth satellites Kepler's third law 128 00:04:39,410 --> 00:04:39,420 earth satellites Kepler's third law 129 00:04:39,420 --> 00:04:42,560 earth satellites Kepler's third law explains that the farther a satellite is 130 00:04:42,560 --> 00:04:42,570 explains that the farther a satellite is 131 00:04:42,570 --> 00:04:44,660 explains that the farther a satellite is from the earth the longer it will take 132 00:04:44,660 --> 00:04:44,670 from the earth the longer it will take 133 00:04:44,670 --> 00:04:47,330 from the earth the longer it will take to complete an orbit the greater the 134 00:04:47,330 --> 00:04:47,340 to complete an orbit the greater the 135 00:04:47,340 --> 00:04:49,340 to complete an orbit the greater the distance it will travel to complete an 136 00:04:49,340 --> 00:04:49,350 distance it will travel to complete an 137 00:04:49,350 --> 00:04:52,040 distance it will travel to complete an orbit and the slower its average speed 138 00:04:52,040 --> 00:04:52,050 orbit and the slower its average speed 139 00:04:52,050 --> 00:04:59,409 orbit and the slower its average speed will be 140 00:04:59,409 --> 00:04:59,419 141 00:04:59,419 --> 00:05:02,299 Isaac Newton the father of classical 142 00:05:02,299 --> 00:05:02,309 Isaac Newton the father of classical 143 00:05:02,309 --> 00:05:04,129 Isaac Newton the father of classical mechanics laid the groundwork for 144 00:05:04,129 --> 00:05:04,139 mechanics laid the groundwork for 145 00:05:04,139 --> 00:05:07,159 mechanics laid the groundwork for orbital mechanics he combined the work 146 00:05:07,159 --> 00:05:07,169 orbital mechanics he combined the work 147 00:05:07,169 --> 00:05:09,379 orbital mechanics he combined the work of Kepler and others to formulate the 148 00:05:09,379 --> 00:05:09,389 of Kepler and others to formulate the 149 00:05:09,389 --> 00:05:12,529 of Kepler and others to formulate the law of universal gravitation and the 150 00:05:12,529 --> 00:05:12,539 law of universal gravitation and the 151 00:05:12,539 --> 00:05:20,059 law of universal gravitation and the three Newtonian laws of motion while 152 00:05:20,059 --> 00:05:20,069 three Newtonian laws of motion while 153 00:05:20,069 --> 00:05:22,369 three Newtonian laws of motion while Kepler's laws provided a conceptual 154 00:05:22,369 --> 00:05:22,379 Kepler's laws provided a conceptual 155 00:05:22,379 --> 00:05:25,219 Kepler's laws provided a conceptual model of orbital motion Newton's laws 156 00:05:25,219 --> 00:05:25,229 model of orbital motion Newton's laws 157 00:05:25,229 --> 00:05:27,109 model of orbital motion Newton's laws provided the foundation for the 158 00:05:27,109 --> 00:05:27,119 provided the foundation for the 159 00:05:27,119 --> 00:05:29,929 provided the foundation for the mathematical description of orbits they 160 00:05:29,929 --> 00:05:29,939 mathematical description of orbits they 161 00:05:29,939 --> 00:05:37,359 mathematical description of orbits they explain why a satellite stays in orbit 162 00:05:37,359 --> 00:05:37,369 163 00:05:37,369 --> 00:05:40,329 Newton's law of universal gravitation 164 00:05:40,329 --> 00:05:40,339 Newton's law of universal gravitation 165 00:05:40,339 --> 00:05:43,519 Newton's law of universal gravitation any two objects in the universe such as 166 00:05:43,519 --> 00:05:43,529 any two objects in the universe such as 167 00:05:43,529 --> 00:05:45,949 any two objects in the universe such as the earth and the moon attract each 168 00:05:45,949 --> 00:05:45,959 the earth and the moon attract each 169 00:05:45,959 --> 00:05:48,379 the earth and the moon attract each other with a force directly proportional 170 00:05:48,379 --> 00:05:48,389 other with a force directly proportional 171 00:05:48,389 --> 00:05:50,359 other with a force directly proportional to the product of their masses and 172 00:05:50,359 --> 00:05:50,369 to the product of their masses and 173 00:05:50,369 --> 00:05:53,149 to the product of their masses and inversely proportional to the square of 174 00:05:53,149 --> 00:05:53,159 inversely proportional to the square of 175 00:05:53,159 --> 00:05:57,529 inversely proportional to the square of the distance between them stated more 176 00:05:57,529 --> 00:05:57,539 the distance between them stated more 177 00:05:57,539 --> 00:06:00,290 the distance between them stated more simply the more massive the objects are 178 00:06:00,290 --> 00:06:00,300 simply the more massive the objects are 179 00:06:00,300 --> 00:06:03,169 simply the more massive the objects are or the closer they are the greater the 180 00:06:03,169 --> 00:06:03,179 or the closer they are the greater the 181 00:06:03,179 --> 00:06:08,479 or the closer they are the greater the gravitational pull between them Newton's 182 00:06:08,479 --> 00:06:08,489 gravitational pull between them Newton's 183 00:06:08,489 --> 00:06:12,049 gravitational pull between them Newton's first law of motion a body in motion 184 00:06:12,049 --> 00:06:12,059 first law of motion a body in motion 185 00:06:12,059 --> 00:06:14,449 first law of motion a body in motion will keep moving in the same speed and 186 00:06:14,449 --> 00:06:14,459 will keep moving in the same speed and 187 00:06:14,459 --> 00:06:16,699 will keep moving in the same speed and in the same direction and let's exit 188 00:06:16,699 --> 00:06:16,709 in the same direction and let's exit 189 00:06:16,709 --> 00:06:21,330 in the same direction and let's exit upon by an external force 190 00:06:21,330 --> 00:06:21,340 191 00:06:21,340 --> 00:06:24,660 a satellite moves in a curved path 192 00:06:24,660 --> 00:06:24,670 a satellite moves in a curved path 193 00:06:24,670 --> 00:06:27,290 a satellite moves in a curved path around the earth because the Earth's 194 00:06:27,290 --> 00:06:27,300 around the earth because the Earth's 195 00:06:27,300 --> 00:06:28,950 around the earth because the Earth's gravitational pull 196 00:06:28,950 --> 00:06:28,960 gravitational pull 197 00:06:28,960 --> 00:06:38,270 gravitational pull acts as an external force on it 198 00:06:38,270 --> 00:06:38,280 199 00:06:38,280 --> 00:06:42,230 Newton's second law of motion if the sum 200 00:06:42,230 --> 00:06:42,240 Newton's second law of motion if the sum 201 00:06:42,240 --> 00:06:44,870 Newton's second law of motion if the sum of the forces acting on an object is not 202 00:06:44,870 --> 00:06:44,880 of the forces acting on an object is not 203 00:06:44,880 --> 00:06:47,330 of the forces acting on an object is not zero the object will have an 204 00:06:47,330 --> 00:06:47,340 zero the object will have an 205 00:06:47,340 --> 00:06:49,490 zero the object will have an acceleration proportional to the 206 00:06:49,490 --> 00:06:49,500 acceleration proportional to the 207 00:06:49,500 --> 00:06:52,070 acceleration proportional to the magnitude and in the direction of the 208 00:06:52,070 --> 00:06:52,080 magnitude and in the direction of the 209 00:06:52,080 --> 00:06:55,670 magnitude and in the direction of the net force newton's second law states 210 00:06:55,670 --> 00:06:55,680 net force newton's second law states 211 00:06:55,680 --> 00:06:58,129 net force newton's second law states that force equals mass times 212 00:06:58,129 --> 00:06:58,139 that force equals mass times 213 00:06:58,139 --> 00:07:01,370 that force equals mass times acceleration it is this mathematical 214 00:07:01,370 --> 00:07:01,380 acceleration it is this mathematical 215 00:07:01,380 --> 00:07:04,040 acceleration it is this mathematical equation and the equation for universal 216 00:07:04,040 --> 00:07:04,050 equation and the equation for universal 217 00:07:04,050 --> 00:07:06,620 equation and the equation for universal gravitation that forms the basis for 218 00:07:06,620 --> 00:07:06,630 gravitation that forms the basis for 219 00:07:06,630 --> 00:07:12,740 gravitation that forms the basis for calculating orbits Newton's third law of 220 00:07:12,740 --> 00:07:12,750 calculating orbits Newton's third law of 221 00:07:12,750 --> 00:07:15,710 calculating orbits Newton's third law of motion explains how a satellite gets 222 00:07:15,710 --> 00:07:15,720 motion explains how a satellite gets 223 00:07:15,720 --> 00:07:19,430 motion explains how a satellite gets into orbit for every action there is an 224 00:07:19,430 --> 00:07:19,440 into orbit for every action there is an 225 00:07:19,440 --> 00:07:22,490 into orbit for every action there is an equal and opposite reaction 226 00:07:22,490 --> 00:07:22,500 equal and opposite reaction 227 00:07:22,500 --> 00:07:25,850 equal and opposite reaction if you blow up a balloon and let it go 228 00:07:25,850 --> 00:07:25,860 if you blow up a balloon and let it go 229 00:07:25,860 --> 00:07:28,010 if you blow up a balloon and let it go the balloon is pushed forward by the 230 00:07:28,010 --> 00:07:28,020 the balloon is pushed forward by the 231 00:07:28,020 --> 00:07:31,780 the balloon is pushed forward by the action of the air rushing out of it a 232 00:07:31,780 --> 00:07:31,790 action of the air rushing out of it a 233 00:07:31,790 --> 00:07:34,850 action of the air rushing out of it a Rockets exhaust gases are like the air 234 00:07:34,850 --> 00:07:34,860 Rockets exhaust gases are like the air 235 00:07:34,860 --> 00:07:40,969 Rockets exhaust gases are like the air rushing out of the balloon the following 236 00:07:40,969 --> 00:07:40,979 rushing out of the balloon the following 237 00:07:40,979 --> 00:07:43,219 rushing out of the balloon the following illustrates how a satellite stays in 238 00:07:43,219 --> 00:07:43,229 illustrates how a satellite stays in 239 00:07:43,229 --> 00:07:48,230 illustrates how a satellite stays in orbit if a man stands on a mountain and 240 00:07:48,230 --> 00:07:48,240 orbit if a man stands on a mountain and 241 00:07:48,240 --> 00:07:51,830 orbit if a man stands on a mountain and fires a projectile horizontally gravity 242 00:07:51,830 --> 00:07:51,840 fires a projectile horizontally gravity 243 00:07:51,840 --> 00:07:53,900 fires a projectile horizontally gravity will cause the path of the projectile to 244 00:07:53,900 --> 00:07:53,910 will cause the path of the projectile to 245 00:07:53,910 --> 00:07:56,060 will cause the path of the projectile to curve downward and it will strike the 246 00:07:56,060 --> 00:07:56,070 curve downward and it will strike the 247 00:07:56,070 --> 00:08:00,100 curve downward and it will strike the earth 248 00:08:00,100 --> 00:08:00,110 249 00:08:00,110 --> 00:08:03,129 however if the man fires the projectile 250 00:08:03,129 --> 00:08:03,139 however if the man fires the projectile 251 00:08:03,139 --> 00:08:06,219 however if the man fires the projectile fast enough at a specific speed the 252 00:08:06,219 --> 00:08:06,229 fast enough at a specific speed the 253 00:08:06,229 --> 00:08:08,350 fast enough at a specific speed the curvature of its path due to gravity 254 00:08:08,350 --> 00:08:08,360 curvature of its path due to gravity 255 00:08:08,360 --> 00:08:10,089 curvature of its path due to gravity will match the curvature of the earth 256 00:08:10,089 --> 00:08:10,099 will match the curvature of the earth 257 00:08:10,099 --> 00:08:13,570 will match the curvature of the earth under it the projectile will then fall 258 00:08:13,570 --> 00:08:13,580 under it the projectile will then fall 259 00:08:13,580 --> 00:08:15,820 under it the projectile will then fall around the earth becoming an earth 260 00:08:15,820 --> 00:08:15,830 around the earth becoming an earth 261 00:08:15,830 --> 00:08:19,360 around the earth becoming an earth orbiting satellite a projectile fired 262 00:08:19,360 --> 00:08:19,370 orbiting satellite a projectile fired 263 00:08:19,370 --> 00:08:21,879 orbiting satellite a projectile fired even faster will have a flight path away 264 00:08:21,879 --> 00:08:21,889 even faster will have a flight path away 265 00:08:21,889 --> 00:08:24,429 even faster will have a flight path away from the earth but gravity will act to 266 00:08:24,429 --> 00:08:24,439 from the earth but gravity will act to 267 00:08:24,439 --> 00:08:26,770 from the earth but gravity will act to slow the projectile down change its 268 00:08:26,770 --> 00:08:26,780 slow the projectile down change its 269 00:08:26,780 --> 00:08:29,320 slow the projectile down change its flight path and pull it back toward 270 00:08:29,320 --> 00:08:29,330 flight path and pull it back toward 271 00:08:29,330 --> 00:08:34,000 flight path and pull it back toward Earth if the projectiles velocity 272 00:08:34,000 --> 00:08:34,010 Earth if the projectiles velocity 273 00:08:34,010 --> 00:08:36,880 Earth if the projectiles velocity increased enough a velocity sufficient 274 00:08:36,880 --> 00:08:36,890 increased enough a velocity sufficient 275 00:08:36,890 --> 00:08:39,130 increased enough a velocity sufficient to escape the Earth's gravitational pull 276 00:08:39,130 --> 00:08:39,140 to escape the Earth's gravitational pull 277 00:08:39,140 --> 00:08:43,089 to escape the Earth's gravitational pull will be reached this velocity is known 278 00:08:43,089 --> 00:08:43,099 will be reached this velocity is known 279 00:08:43,099 --> 00:08:46,060 will be reached this velocity is known as the escape velocity it is equal to 280 00:08:46,060 --> 00:08:46,070 as the escape velocity it is equal to 281 00:08:46,070 --> 00:08:48,460 as the escape velocity it is equal to about seven miles per second at the 282 00:08:48,460 --> 00:08:48,470 about seven miles per second at the 283 00:08:48,470 --> 00:08:51,370 about seven miles per second at the Earth's surface the preceding 284 00:08:51,370 --> 00:08:51,380 Earth's surface the preceding 285 00:08:51,380 --> 00:08:53,710 Earth's surface the preceding description did not consider atmospheric 286 00:08:53,710 --> 00:08:53,720 description did not consider atmospheric 287 00:08:53,720 --> 00:08:56,560 description did not consider atmospheric drag and the Earth's rotation both of 288 00:08:56,560 --> 00:08:56,570 drag and the Earth's rotation both of 289 00:08:56,570 --> 00:08:58,509 drag and the Earth's rotation both of which will affect the trajectory of the 290 00:08:58,509 --> 00:08:58,519 which will affect the trajectory of the 291 00:08:58,519 --> 00:09:01,210 which will affect the trajectory of the projectile it Illustrated the principles 292 00:09:01,210 --> 00:09:01,220 projectile it Illustrated the principles 293 00:09:01,220 --> 00:09:07,139 projectile it Illustrated the principles governing a satellites orbit 294 00:09:07,139 --> 00:09:07,149 295 00:09:07,149 --> 00:09:10,420 there are six numbers called the orbital 296 00:09:10,420 --> 00:09:10,430 there are six numbers called the orbital 297 00:09:10,430 --> 00:09:13,509 there are six numbers called the orbital elements which specify the size shape 298 00:09:13,509 --> 00:09:13,519 elements which specify the size shape 299 00:09:13,519 --> 00:09:16,930 elements which specify the size shape and orientation of an orbit in space as 300 00:09:16,930 --> 00:09:16,940 and orientation of an orbit in space as 301 00:09:16,940 --> 00:09:19,090 and orientation of an orbit in space as well as the location of the spacecraft 302 00:09:19,090 --> 00:09:19,100 well as the location of the spacecraft 303 00:09:19,100 --> 00:09:22,900 well as the location of the spacecraft in the orbit based on an orbit which is 304 00:09:22,900 --> 00:09:22,910 in the orbit based on an orbit which is 305 00:09:22,910 --> 00:09:27,000 in the orbit based on an orbit which is an ellipse the six orbital elements are 306 00:09:27,000 --> 00:09:27,010 an ellipse the six orbital elements are 307 00:09:27,010 --> 00:09:31,710 an ellipse the six orbital elements are length of the semi-major axis 308 00:09:31,710 --> 00:09:31,720 309 00:09:31,720 --> 00:09:39,250 eccentricity inclination right ascension 310 00:09:39,250 --> 00:09:39,260 eccentricity inclination right ascension 311 00:09:39,260 --> 00:09:43,780 eccentricity inclination right ascension of the ascending node argument of 312 00:09:43,780 --> 00:09:43,790 of the ascending node argument of 313 00:09:43,790 --> 00:09:50,019 of the ascending node argument of perigee time of perigee passage the 314 00:09:50,019 --> 00:09:50,029 perigee time of perigee passage the 315 00:09:50,029 --> 00:09:52,600 perigee time of perigee passage the major axis of an elliptical orbit is the 316 00:09:52,600 --> 00:09:52,610 major axis of an elliptical orbit is the 317 00:09:52,610 --> 00:09:57,220 major axis of an elliptical orbit is the line joining the perigee and Apogee this 318 00:09:57,220 --> 00:09:57,230 line joining the perigee and Apogee this 319 00:09:57,230 --> 00:09:59,980 line joining the perigee and Apogee this line is also referred to as the line of 320 00:09:59,980 --> 00:09:59,990 line is also referred to as the line of 321 00:09:59,990 --> 00:10:05,380 line is also referred to as the line of APSA DS the first orbital element is the 322 00:10:05,380 --> 00:10:05,390 APSA DS the first orbital element is the 323 00:10:05,390 --> 00:10:08,290 APSA DS the first orbital element is the semi-major axis it is simply one-half 324 00:10:08,290 --> 00:10:08,300 semi-major axis it is simply one-half 325 00:10:08,300 --> 00:10:12,100 semi-major axis it is simply one-half the major axis circular orbits have no 326 00:10:12,100 --> 00:10:12,110 the major axis circular orbits have no 327 00:10:12,110 --> 00:10:14,500 the major axis circular orbits have no Apogee or perigee therefore the 328 00:10:14,500 --> 00:10:14,510 Apogee or perigee therefore the 329 00:10:14,510 --> 00:10:17,380 Apogee or perigee therefore the semi-major axis is simply 1/2 the 330 00:10:17,380 --> 00:10:17,390 semi-major axis is simply 1/2 the 331 00:10:17,390 --> 00:10:21,310 semi-major axis is simply 1/2 the diameter of the orbit the semi-major 332 00:10:21,310 --> 00:10:21,320 diameter of the orbit the semi-major 333 00:10:21,320 --> 00:10:24,069 diameter of the orbit the semi-major axis is used to define the size of the 334 00:10:24,069 --> 00:10:24,079 axis is used to define the size of the 335 00:10:24,079 --> 00:10:27,250 axis is used to define the size of the orbit from this the orbital period or 336 00:10:27,250 --> 00:10:27,260 orbit from this the orbital period or 337 00:10:27,260 --> 00:10:29,380 orbit from this the orbital period or time that it takes for the satellite to 338 00:10:29,380 --> 00:10:29,390 time that it takes for the satellite to 339 00:10:29,390 --> 00:10:34,890 time that it takes for the satellite to complete one orbit can be calculated 340 00:10:34,890 --> 00:10:34,900 341 00:10:34,900 --> 00:10:38,140 the shape of an orbit is defined by the 342 00:10:38,140 --> 00:10:38,150 the shape of an orbit is defined by the 343 00:10:38,150 --> 00:10:39,910 the shape of an orbit is defined by the second orbital element called 344 00:10:39,910 --> 00:10:39,920 second orbital element called 345 00:10:39,920 --> 00:10:44,830 second orbital element called eccentricity for all ellipses the value 346 00:10:44,830 --> 00:10:44,840 eccentricity for all ellipses the value 347 00:10:44,840 --> 00:10:47,080 eccentricity for all ellipses the value of eccentricity lies between zero and 348 00:10:47,080 --> 00:10:47,090 of eccentricity lies between zero and 349 00:10:47,090 --> 00:10:49,630 of eccentricity lies between zero and one the larger the value the more 350 00:10:49,630 --> 00:10:49,640 one the larger the value the more 351 00:10:49,640 --> 00:10:53,020 one the larger the value the more elliptical the orbit a spacecraft in 352 00:10:53,020 --> 00:10:53,030 elliptical the orbit a spacecraft in 353 00:10:53,030 --> 00:10:55,330 elliptical the orbit a spacecraft in Earth orbit with an eccentricity equal 354 00:10:55,330 --> 00:10:55,340 Earth orbit with an eccentricity equal 355 00:10:55,340 --> 00:10:58,390 Earth orbit with an eccentricity equal to or greater than one will escape the 356 00:10:58,390 --> 00:10:58,400 to or greater than one will escape the 357 00:10:58,400 --> 00:11:04,420 to or greater than one will escape the Earth's gravitational field when 358 00:11:04,420 --> 00:11:04,430 Earth's gravitational field when 359 00:11:04,430 --> 00:11:06,910 Earth's gravitational field when orienting an orbit in space a three 360 00:11:06,910 --> 00:11:06,920 orienting an orbit in space a three 361 00:11:06,920 --> 00:11:09,100 orienting an orbit in space a three dimensional coordinate system must be 362 00:11:09,100 --> 00:11:09,110 dimensional coordinate system must be 363 00:11:09,110 --> 00:11:12,670 dimensional coordinate system must be defined the coordinate system commonly 364 00:11:12,670 --> 00:11:12,680 defined the coordinate system commonly 365 00:11:12,680 --> 00:11:15,490 defined the coordinate system commonly used is the geocentric equatorial 366 00:11:15,490 --> 00:11:15,500 used is the geocentric equatorial 367 00:11:15,500 --> 00:11:18,070 used is the geocentric equatorial coordinate system which has its origin 368 00:11:18,070 --> 00:11:18,080 coordinate system which has its origin 369 00:11:18,080 --> 00:11:20,710 coordinate system which has its origin at the Earth's center 370 00:11:20,710 --> 00:11:20,720 at the Earth's center 371 00:11:20,720 --> 00:11:23,440 at the Earth's center this coordinate system is a non-rotating 372 00:11:23,440 --> 00:11:23,450 this coordinate system is a non-rotating 373 00:11:23,450 --> 00:11:26,200 this coordinate system is a non-rotating reference system in which a satellites 374 00:11:26,200 --> 00:11:26,210 reference system in which a satellites 375 00:11:26,210 --> 00:11:29,020 reference system in which a satellites orbital plane tends to remain fixed 376 00:11:29,020 --> 00:11:29,030 orbital plane tends to remain fixed 377 00:11:29,030 --> 00:11:31,390 orbital plane tends to remain fixed relative to the stars while the Earth 378 00:11:31,390 --> 00:11:31,400 relative to the stars while the Earth 379 00:11:31,400 --> 00:11:36,220 relative to the stars while the Earth turns beneath it the XY plane is the 380 00:11:36,220 --> 00:11:36,230 turns beneath it the XY plane is the 381 00:11:36,230 --> 00:11:38,860 turns beneath it the XY plane is the Earth's equatorial plane the positive 382 00:11:38,860 --> 00:11:38,870 Earth's equatorial plane the positive 383 00:11:38,870 --> 00:11:43,540 Earth's equatorial plane the positive x-axis points to the vernal equinox this 384 00:11:43,540 --> 00:11:43,550 x-axis points to the vernal equinox this 385 00:11:43,550 --> 00:11:45,370 x-axis points to the vernal equinox this is the point where the Sun appears to 386 00:11:45,370 --> 00:11:45,380 is the point where the Sun appears to 387 00:11:45,380 --> 00:11:47,560 is the point where the Sun appears to cross the earth's equator on its way 388 00:11:47,560 --> 00:11:47,570 cross the earth's equator on its way 389 00:11:47,570 --> 00:11:49,900 cross the earth's equator on its way north on the first day of spring each 390 00:11:49,900 --> 00:11:49,910 north on the first day of spring each 391 00:11:49,910 --> 00:11:54,160 north on the first day of spring each year the z axis is along the Earth's 392 00:11:54,160 --> 00:11:54,170 year the z axis is along the Earth's 393 00:11:54,170 --> 00:12:00,040 year the z axis is along the Earth's spin axis toward the North Pole nodes 394 00:12:00,040 --> 00:12:00,050 spin axis toward the North Pole nodes 395 00:12:00,050 --> 00:12:02,500 spin axis toward the North Pole nodes are points in a satellites orbit which 396 00:12:02,500 --> 00:12:02,510 are points in a satellites orbit which 397 00:12:02,510 --> 00:12:05,730 are points in a satellites orbit which intersect the Earth's equatorial plane 398 00:12:05,730 --> 00:12:05,740 intersect the Earth's equatorial plane 399 00:12:05,740 --> 00:12:08,860 intersect the Earth's equatorial plane the ascending node is the point at which 400 00:12:08,860 --> 00:12:08,870 the ascending node is the point at which 401 00:12:08,870 --> 00:12:11,740 the ascending node is the point at which the spacecraft crosses the equator going 402 00:12:11,740 --> 00:12:11,750 the spacecraft crosses the equator going 403 00:12:11,750 --> 00:12:15,970 the spacecraft crosses the equator going from south to north the descending node 404 00:12:15,970 --> 00:12:15,980 from south to north the descending node 405 00:12:15,980 --> 00:12:18,070 from south to north the descending node is where the spacecraft crosses the 406 00:12:18,070 --> 00:12:18,080 is where the spacecraft crosses the 407 00:12:18,080 --> 00:12:22,180 is where the spacecraft crosses the equator going from north to south the 408 00:12:22,180 --> 00:12:22,190 equator going from north to south the 409 00:12:22,190 --> 00:12:24,430 equator going from north to south the line joining the two nodes is called the 410 00:12:24,430 --> 00:12:24,440 line joining the two nodes is called the 411 00:12:24,440 --> 00:12:28,780 line joining the two nodes is called the line of nodes the orientation of an 412 00:12:28,780 --> 00:12:28,790 line of nodes the orientation of an 413 00:12:28,790 --> 00:12:31,240 line of nodes the orientation of an orbit is determined by three orbital 414 00:12:31,240 --> 00:12:31,250 orbit is determined by three orbital 415 00:12:31,250 --> 00:12:35,920 orbit is determined by three orbital element angles the right ascension of 416 00:12:35,920 --> 00:12:35,930 element angles the right ascension of 417 00:12:35,930 --> 00:12:38,110 element angles the right ascension of the ascending node is the angle between 418 00:12:38,110 --> 00:12:38,120 the ascending node is the angle between 419 00:12:38,120 --> 00:12:41,260 the ascending node is the angle between the x-axis and the ascending node it is 420 00:12:41,260 --> 00:12:41,270 the x-axis and the ascending node it is 421 00:12:41,270 --> 00:12:43,660 the x-axis and the ascending node it is always measured eastward from the 422 00:12:43,660 --> 00:12:43,670 always measured eastward from the 423 00:12:43,670 --> 00:12:45,820 always measured eastward from the direction away from the vernal equinox 424 00:12:45,820 --> 00:12:45,830 direction away from the vernal equinox 425 00:12:45,830 --> 00:12:52,850 direction away from the vernal equinox in the Earth's equatorial plane 426 00:12:52,850 --> 00:12:52,860 427 00:12:52,860 --> 00:12:55,880 the argument of perigee is the angle 428 00:12:55,880 --> 00:12:55,890 the argument of perigee is the angle 429 00:12:55,890 --> 00:12:58,100 the argument of perigee is the angle between the ascending node and the point 430 00:12:58,100 --> 00:12:58,110 between the ascending node and the point 431 00:12:58,110 --> 00:13:00,950 between the ascending node and the point of perigee it is measured in the orbital 432 00:13:00,950 --> 00:13:00,960 of perigee it is measured in the orbital 433 00:13:00,960 --> 00:13:02,930 of perigee it is measured in the orbital plane in the direction of spacecraft 434 00:13:02,930 --> 00:13:02,940 plane in the direction of spacecraft 435 00:13:02,940 --> 00:13:07,970 plane in the direction of spacecraft motion inclination is the angle between 436 00:13:07,970 --> 00:13:07,980 motion inclination is the angle between 437 00:13:07,980 --> 00:13:10,640 motion inclination is the angle between the equatorial plane and the orbital 438 00:13:10,640 --> 00:13:10,650 the equatorial plane and the orbital 439 00:13:10,650 --> 00:13:15,470 the equatorial plane and the orbital plane a satellite which has an eastward 440 00:13:15,470 --> 00:13:15,480 plane a satellite which has an eastward 441 00:13:15,480 --> 00:13:18,020 plane a satellite which has an eastward velocity component at the ascending node 442 00:13:18,020 --> 00:13:18,030 velocity component at the ascending node 443 00:13:18,030 --> 00:13:20,900 velocity component at the ascending node as an orbital inclination lying between 444 00:13:20,900 --> 00:13:20,910 as an orbital inclination lying between 445 00:13:20,910 --> 00:13:24,620 as an orbital inclination lying between 0 and 90 degrees such an orbit is called 446 00:13:24,620 --> 00:13:24,630 0 and 90 degrees such an orbit is called 447 00:13:24,630 --> 00:13:32,140 0 and 90 degrees such an orbit is called a pro-grade orbit 448 00:13:32,140 --> 00:13:32,150 449 00:13:32,150 --> 00:13:34,990 a satellite which moves due north at the 450 00:13:34,990 --> 00:13:35,000 a satellite which moves due north at the 451 00:13:35,000 --> 00:13:38,290 a satellite which moves due north at the ascending node is in a polar orbit polar 452 00:13:38,290 --> 00:13:38,300 ascending node is in a polar orbit polar 453 00:13:38,300 --> 00:13:40,510 ascending node is in a polar orbit polar orbits have an orbital inclination of 454 00:13:40,510 --> 00:13:40,520 orbits have an orbital inclination of 455 00:13:40,520 --> 00:13:45,250 orbits have an orbital inclination of exactly 90 degrees a satellite with a 456 00:13:45,250 --> 00:13:45,260 exactly 90 degrees a satellite with a 457 00:13:45,260 --> 00:13:47,290 exactly 90 degrees a satellite with a westward velocity component at the 458 00:13:47,290 --> 00:13:47,300 westward velocity component at the 459 00:13:47,300 --> 00:13:49,930 westward velocity component at the ascending node is in a retrograde orbit 460 00:13:49,930 --> 00:13:49,940 ascending node is in a retrograde orbit 461 00:13:49,940 --> 00:13:52,060 ascending node is in a retrograde orbit and has an orbital inclination between 462 00:13:52,060 --> 00:13:52,070 and has an orbital inclination between 463 00:13:52,070 --> 00:13:55,670 and has an orbital inclination between 90 and 180 degrees 464 00:13:55,670 --> 00:13:55,680 90 and 180 degrees 465 00:13:55,680 --> 00:13:58,730 90 and 180 degrees the five orbital elements explained thus 466 00:13:58,730 --> 00:13:58,740 the five orbital elements explained thus 467 00:13:58,740 --> 00:14:01,400 the five orbital elements explained thus far described the size shape and 468 00:14:01,400 --> 00:14:01,410 far described the size shape and 469 00:14:01,410 --> 00:14:04,730 far described the size shape and orientation of the orbit in space the 470 00:14:04,730 --> 00:14:04,740 orientation of the orbit in space the 471 00:14:04,740 --> 00:14:07,189 orientation of the orbit in space the final element is a time value used to 472 00:14:07,189 --> 00:14:07,199 final element is a time value used to 473 00:14:07,199 --> 00:14:09,730 final element is a time value used to locate the satellite in its orbit a 474 00:14:09,730 --> 00:14:09,740 locate the satellite in its orbit a 475 00:14:09,740 --> 00:14:12,739 locate the satellite in its orbit a satellite moves in a very predictable 476 00:14:12,739 --> 00:14:12,749 satellite moves in a very predictable 477 00:14:12,749 --> 00:14:13,280 satellite moves in a very predictable manner 478 00:14:13,280 --> 00:14:13,290 manner 479 00:14:13,290 --> 00:14:16,249 manner it stays on schedule thus if the time at 480 00:14:16,249 --> 00:14:16,259 it stays on schedule thus if the time at 481 00:14:16,259 --> 00:14:18,350 it stays on schedule thus if the time at which a satellite passes a particular 482 00:14:18,350 --> 00:14:18,360 which a satellite passes a particular 483 00:14:18,360 --> 00:14:20,660 which a satellite passes a particular point is known the time when it will 484 00:14:20,660 --> 00:14:20,670 point is known the time when it will 485 00:14:20,670 --> 00:14:23,679 point is known the time when it will pass any other point can be determined 486 00:14:23,679 --> 00:14:23,689 pass any other point can be determined 487 00:14:23,689 --> 00:14:26,989 pass any other point can be determined the particular point chosen is perigee 488 00:14:26,989 --> 00:14:26,999 the particular point chosen is perigee 489 00:14:26,999 --> 00:14:29,540 the particular point chosen is perigee and the time of perigee passage is the 490 00:14:29,540 --> 00:14:29,550 and the time of perigee passage is the 491 00:14:29,550 --> 00:14:35,720 and the time of perigee passage is the last of the six orbital elements the six 492 00:14:35,720 --> 00:14:35,730 last of the six orbital elements the six 493 00:14:35,730 --> 00:14:38,150 last of the six orbital elements the six orbital elements depict a spacecrafts 494 00:14:38,150 --> 00:14:38,160 orbital elements depict a spacecrafts 495 00:14:38,160 --> 00:14:41,869 orbital elements depict a spacecrafts orbit in non rotating coordinates to 496 00:14:41,869 --> 00:14:41,879 orbit in non rotating coordinates to 497 00:14:41,879 --> 00:14:43,999 orbit in non rotating coordinates to visualize an orbit relative to the 498 00:14:43,999 --> 00:14:44,009 visualize an orbit relative to the 499 00:14:44,009 --> 00:14:46,759 visualize an orbit relative to the rotating earth a projection traces the 500 00:14:46,759 --> 00:14:46,769 rotating earth a projection traces the 501 00:14:46,769 --> 00:14:48,769 rotating earth a projection traces the spacecraft's position on the Earth's 502 00:14:48,769 --> 00:14:48,779 spacecraft's position on the Earth's 503 00:14:48,779 --> 00:14:53,090 spacecraft's position on the Earth's surface the projected path is called the 504 00:14:53,090 --> 00:14:53,100 surface the projected path is called the 505 00:14:53,100 --> 00:14:58,220 surface the projected path is called the ground track as a satellite orbits the 506 00:14:58,220 --> 00:14:58,230 ground track as a satellite orbits the 507 00:14:58,230 --> 00:15:00,970 ground track as a satellite orbits the earth the ground track shifts westward 508 00:15:00,970 --> 00:15:00,980 earth the ground track shifts westward 509 00:15:00,980 --> 00:15:04,669 earth the ground track shifts westward there are two causes for this first the 510 00:15:04,669 --> 00:15:04,679 there are two causes for this first the 511 00:15:04,679 --> 00:15:06,439 there are two causes for this first the primary contributor is the Earth's 512 00:15:06,439 --> 00:15:06,449 primary contributor is the Earth's 513 00:15:06,449 --> 00:15:09,110 primary contributor is the Earth's rotation toward the east under the 514 00:15:09,110 --> 00:15:09,120 rotation toward the east under the 515 00:15:09,120 --> 00:15:12,679 rotation toward the east under the orbital plane second because the earth 516 00:15:12,679 --> 00:15:12,689 orbital plane second because the earth 517 00:15:12,689 --> 00:15:15,199 orbital plane second because the earth is not a uniform sphere and bulges at 518 00:15:15,199 --> 00:15:15,209 is not a uniform sphere and bulges at 519 00:15:15,209 --> 00:15:18,049 is not a uniform sphere and bulges at the equator its gravity is greatest at 520 00:15:18,049 --> 00:15:18,059 the equator its gravity is greatest at 521 00:15:18,059 --> 00:15:18,889 the equator its gravity is greatest at the equator 522 00:15:18,889 --> 00:15:18,899 the equator 523 00:15:18,899 --> 00:15:21,889 the equator this causes the orbital plane to rotate 524 00:15:21,889 --> 00:15:21,899 this causes the orbital plane to rotate 525 00:15:21,899 --> 00:15:24,769 this causes the orbital plane to rotate slowly around the Earth's polar axis in 526 00:15:24,769 --> 00:15:24,779 slowly around the Earth's polar axis in 527 00:15:24,779 --> 00:15:29,840 slowly around the Earth's polar axis in a motion called precession precession is 528 00:15:29,840 --> 00:15:29,850 a motion called precession precession is 529 00:15:29,850 --> 00:15:32,090 a motion called precession precession is toward the west where pro-grade orbits 530 00:15:32,090 --> 00:15:32,100 toward the west where pro-grade orbits 531 00:15:32,100 --> 00:15:34,009 toward the west where pro-grade orbits and toward the east for retrograde 532 00:15:34,009 --> 00:15:34,019 and toward the east for retrograde 533 00:15:34,019 --> 00:15:36,009 and toward the east for retrograde orbits 534 00:15:36,009 --> 00:15:36,019 orbits 535 00:15:36,019 --> 00:15:38,749 orbits for low Earth orbits such as those of 536 00:15:38,749 --> 00:15:38,759 for low Earth orbits such as those of 537 00:15:38,759 --> 00:15:41,420 for low Earth orbits such as those of the space shuttle at 150 miles altitude 538 00:15:41,420 --> 00:15:41,430 the space shuttle at 150 miles altitude 539 00:15:41,430 --> 00:15:44,119 the space shuttle at 150 miles altitude the westward shift of the ground track 540 00:15:44,119 --> 00:15:44,129 the westward shift of the ground track 541 00:15:44,129 --> 00:15:47,240 the westward shift of the ground track due to the Earth's rotation is about 22 542 00:15:47,240 --> 00:15:47,250 due to the Earth's rotation is about 22 543 00:15:47,250 --> 00:15:49,639 due to the Earth's rotation is about 22 and a half degrees while the shift due 544 00:15:49,639 --> 00:15:49,649 and a half degrees while the shift due 545 00:15:49,649 --> 00:15:51,889 and a half degrees while the shift due to precession is only about a half 546 00:15:51,889 --> 00:15:51,899 to precession is only about a half 547 00:15:51,899 --> 00:15:57,290 to precession is only about a half degree the inclination of a satellite 548 00:15:57,290 --> 00:15:57,300 degree the inclination of a satellite 549 00:15:57,300 --> 00:15:59,449 degree the inclination of a satellite orbit determines the north and south 550 00:15:59,449 --> 00:15:59,459 orbit determines the north and south 551 00:15:59,459 --> 00:16:03,410 orbit determines the north and south latitude limits of its ground track the 552 00:16:03,410 --> 00:16:03,420 latitude limits of its ground track the 553 00:16:03,420 --> 00:16:06,110 latitude limits of its ground track the minimum orbital inclination is equal to 554 00:16:06,110 --> 00:16:06,120 minimum orbital inclination is equal to 555 00:16:06,120 --> 00:16:08,569 minimum orbital inclination is equal to the latitude of the launch site and is 556 00:16:08,569 --> 00:16:08,579 the latitude of the launch site and is 557 00:16:08,579 --> 00:16:13,189 the latitude of the launch site and is achieved by launching due east for 558 00:16:13,189 --> 00:16:13,199 achieved by launching due east for 559 00:16:13,199 --> 00:16:15,679 achieved by launching due east for example if a satellite is launched due 560 00:16:15,679 --> 00:16:15,689 example if a satellite is launched due 561 00:16:15,689 --> 00:16:17,360 example if a satellite is launched due east out of the Kennedy Space Center 562 00:16:17,360 --> 00:16:17,370 east out of the Kennedy Space Center 563 00:16:17,370 --> 00:16:20,030 east out of the Kennedy Space Center which is located at 28 and a half 564 00:16:20,030 --> 00:16:20,040 which is located at 28 and a half 565 00:16:20,040 --> 00:16:22,910 which is located at 28 and a half degrees north latitude its orbital 566 00:16:22,910 --> 00:16:22,920 degrees north latitude its orbital 567 00:16:22,920 --> 00:16:25,160 degrees north latitude its orbital inclination will be 28 and 1/2 degrees 568 00:16:25,160 --> 00:16:25,170 inclination will be 28 and 1/2 degrees 569 00:16:25,170 --> 00:16:28,100 inclination will be 28 and 1/2 degrees and the limits of its ground track will 570 00:16:28,100 --> 00:16:28,110 and the limits of its ground track will 571 00:16:28,110 --> 00:16:30,679 and the limits of its ground track will vary between 28 and 1/2 degrees north 572 00:16:30,679 --> 00:16:30,689 vary between 28 and 1/2 degrees north 573 00:16:30,689 --> 00:16:33,650 vary between 28 and 1/2 degrees north latitude and 28 and 1/2 degrees south 574 00:16:33,650 --> 00:16:33,660 latitude and 28 and 1/2 degrees south 575 00:16:33,660 --> 00:16:37,819 latitude and 28 and 1/2 degrees south latitude if launch azimuth or direction 576 00:16:37,819 --> 00:16:37,829 latitude if launch azimuth or direction 577 00:16:37,829 --> 00:16:40,069 latitude if launch azimuth or direction of flight at launch measured eastward 578 00:16:40,069 --> 00:16:40,079 of flight at launch measured eastward 579 00:16:40,079 --> 00:16:43,009 of flight at launch measured eastward from due north is increased from due 580 00:16:43,009 --> 00:16:43,019 from due north is increased from due 581 00:16:43,019 --> 00:16:43,639 from due north is increased from due east 582 00:16:43,639 --> 00:16:43,649 east 583 00:16:43,649 --> 00:16:46,490 east the orbital inclination angle increases 584 00:16:46,490 --> 00:16:46,500 the orbital inclination angle increases 585 00:16:46,500 --> 00:16:49,069 the orbital inclination angle increases as well as the maximum latitude of the 586 00:16:49,069 --> 00:16:49,079 as well as the maximum latitude of the 587 00:16:49,079 --> 00:16:53,600 as well as the maximum latitude of the north-south ground track therefore the 588 00:16:53,600 --> 00:16:53,610 north-south ground track therefore the 589 00:16:53,610 --> 00:16:55,579 north-south ground track therefore the latitude limits of the ground track 590 00:16:55,579 --> 00:16:55,589 latitude limits of the ground track 591 00:16:55,589 --> 00:16:59,199 latitude limits of the ground track equal the new launch inclination 592 00:16:59,199 --> 00:16:59,209 equal the new launch inclination 593 00:16:59,209 --> 00:17:01,850 equal the new launch inclination similarly if launched azimuth is 594 00:17:01,850 --> 00:17:01,860 similarly if launched azimuth is 595 00:17:01,860 --> 00:17:04,549 similarly if launched azimuth is decreased from due east orbital 596 00:17:04,549 --> 00:17:04,559 decreased from due east orbital 597 00:17:04,559 --> 00:17:07,789 decreased from due east orbital inclination once again increases as well 598 00:17:07,789 --> 00:17:07,799 inclination once again increases as well 599 00:17:07,799 --> 00:17:09,740 inclination once again increases as well as the latitude limits of the ground 600 00:17:09,740 --> 00:17:09,750 as the latitude limits of the ground 601 00:17:09,750 --> 00:17:12,299 as the latitude limits of the ground track 602 00:17:12,299 --> 00:17:12,309 603 00:17:12,309 --> 00:17:15,490 the maximum practical inclination from a 604 00:17:15,490 --> 00:17:15,500 the maximum practical inclination from a 605 00:17:15,500 --> 00:17:18,039 the maximum practical inclination from a Kennedy Space Center launch is 57 606 00:17:18,039 --> 00:17:18,049 Kennedy Space Center launch is 57 607 00:17:18,049 --> 00:17:21,189 Kennedy Space Center launch is 57 degrees this limit is imposed for safety 608 00:17:21,189 --> 00:17:21,199 degrees this limit is imposed for safety 609 00:17:21,199 --> 00:17:23,379 degrees this limit is imposed for safety considerations in order to keep the 610 00:17:23,379 --> 00:17:23,389 considerations in order to keep the 611 00:17:23,389 --> 00:17:25,870 considerations in order to keep the spacecraft and its booster system from 612 00:17:25,870 --> 00:17:25,880 spacecraft and its booster system from 613 00:17:25,880 --> 00:17:27,970 spacecraft and its booster system from flying over land masses during the 614 00:17:27,970 --> 00:17:27,980 flying over land masses during the 615 00:17:27,980 --> 00:17:32,560 flying over land masses during the ascent phase to obtain an orbit with an 616 00:17:32,560 --> 00:17:32,570 ascent phase to obtain an orbit with an 617 00:17:32,570 --> 00:17:35,590 ascent phase to obtain an orbit with an inclination greater than 57 degrees the 618 00:17:35,590 --> 00:17:35,600 inclination greater than 57 degrees the 619 00:17:35,600 --> 00:17:37,180 inclination greater than 57 degrees the spacecraft is launched from Vandenberg 620 00:17:37,180 --> 00:17:37,190 spacecraft is launched from Vandenberg 621 00:17:37,190 --> 00:17:40,049 spacecraft is launched from Vandenberg Air Force Base in California 622 00:17:40,049 --> 00:17:40,059 Air Force Base in California 623 00:17:40,059 --> 00:17:42,490 Air Force Base in California Vandenberg offers the opportunity for 624 00:17:42,490 --> 00:17:42,500 Vandenberg offers the opportunity for 625 00:17:42,500 --> 00:17:44,560 Vandenberg offers the opportunity for southerly launches with orbit 626 00:17:44,560 --> 00:17:44,570 southerly launches with orbit 627 00:17:44,570 --> 00:17:47,230 southerly launches with orbit inclinations between approximately 70 628 00:17:47,230 --> 00:17:47,240 inclinations between approximately 70 629 00:17:47,240 --> 00:17:50,049 inclinations between approximately 70 degrees pro-grade through 138 degrees 630 00:17:50,049 --> 00:17:50,059 degrees pro-grade through 138 degrees 631 00:17:50,059 --> 00:17:54,129 degrees pro-grade through 138 degrees retrograde a significant advantage of 632 00:17:54,129 --> 00:17:54,139 retrograde a significant advantage of 633 00:17:54,139 --> 00:17:56,019 retrograde a significant advantage of launching from Vandenberg is the 634 00:17:56,019 --> 00:17:56,029 launching from Vandenberg is the 635 00:17:56,029 --> 00:17:58,629 launching from Vandenberg is the capability to economically achieve polar 636 00:17:58,629 --> 00:17:58,639 capability to economically achieve polar 637 00:17:58,639 --> 00:18:01,119 capability to economically achieve polar orbits with ground tracks covering all 638 00:18:01,119 --> 00:18:01,129 orbits with ground tracks covering all 639 00:18:01,129 --> 00:18:03,460 orbits with ground tracks covering all latitudes from the North Pole to the 640 00:18:03,460 --> 00:18:03,470 latitudes from the North Pole to the 641 00:18:03,470 --> 00:18:07,119 latitudes from the North Pole to the South Pole the earth is constantly 642 00:18:07,119 --> 00:18:07,129 South Pole the earth is constantly 643 00:18:07,129 --> 00:18:09,730 South Pole the earth is constantly turning and all points on its surface 644 00:18:09,730 --> 00:18:09,740 turning and all points on its surface 645 00:18:09,740 --> 00:18:11,769 turning and all points on its surface have an eastward velocity with the 646 00:18:11,769 --> 00:18:11,779 have an eastward velocity with the 647 00:18:11,779 --> 00:18:13,779 have an eastward velocity with the greatest velocity occurring at the 648 00:18:13,779 --> 00:18:13,789 greatest velocity occurring at the 649 00:18:13,789 --> 00:18:17,289 greatest velocity occurring at the equator the farther the launch site is 650 00:18:17,289 --> 00:18:17,299 equator the farther the launch site is 651 00:18:17,299 --> 00:18:20,169 equator the farther the launch site is from the equator or as launch azimuth is 652 00:18:20,169 --> 00:18:20,179 from the equator or as launch azimuth is 653 00:18:20,179 --> 00:18:22,389 from the equator or as launch azimuth is increased or decreased from due east 654 00:18:22,389 --> 00:18:22,399 increased or decreased from due east 655 00:18:22,399 --> 00:18:25,149 increased or decreased from due east less of the Earth's rotational velocity 656 00:18:25,149 --> 00:18:25,159 less of the Earth's rotational velocity 657 00:18:25,159 --> 00:18:27,749 less of the Earth's rotational velocity will be imparted to the launch vehicle 658 00:18:27,749 --> 00:18:27,759 will be imparted to the launch vehicle 659 00:18:27,759 --> 00:18:30,730 will be imparted to the launch vehicle this requires more fuel to get into 660 00:18:30,730 --> 00:18:30,740 this requires more fuel to get into 661 00:18:30,740 --> 00:18:33,100 this requires more fuel to get into orbit or payload weight will have to be 662 00:18:33,100 --> 00:18:33,110 orbit or payload weight will have to be 663 00:18:33,110 --> 00:18:37,869 orbit or payload weight will have to be decreased launches due east from a 664 00:18:37,869 --> 00:18:37,879 decreased launches due east from a 665 00:18:37,879 --> 00:18:40,330 decreased launches due east from a position on or near the equator such as 666 00:18:40,330 --> 00:18:40,340 position on or near the equator such as 667 00:18:40,340 --> 00:18:42,249 position on or near the equator such as the kuru launch site in French Guiana 668 00:18:42,249 --> 00:18:42,259 the kuru launch site in French Guiana 669 00:18:42,259 --> 00:18:45,100 the kuru launch site in French Guiana used by the European Space Agency 670 00:18:45,100 --> 00:18:45,110 used by the European Space Agency 671 00:18:45,110 --> 00:18:47,980 used by the European Space Agency acquire the advantage of a free velocity 672 00:18:47,980 --> 00:18:47,990 acquire the advantage of a free velocity 673 00:18:47,990 --> 00:18:52,150 acquire the advantage of a free velocity gain of about 1500 feet per second 674 00:18:52,150 --> 00:18:52,160 gain of about 1500 feet per second 675 00:18:52,160 --> 00:18:55,640 gain of about 1500 feet per second this compares to the approximate 1,300 676 00:18:55,640 --> 00:18:55,650 this compares to the approximate 1,300 677 00:18:55,650 --> 00:18:58,070 this compares to the approximate 1,300 feet per second gain available at the 678 00:18:58,070 --> 00:18:58,080 feet per second gain available at the 679 00:18:58,080 --> 00:19:00,170 feet per second gain available at the further north latitude of the Kennedy 680 00:19:00,170 --> 00:19:00,180 further north latitude of the Kennedy 681 00:19:00,180 --> 00:19:05,450 further north latitude of the Kennedy Space Center launching from an 682 00:19:05,450 --> 00:19:05,460 Space Center launching from an 683 00:19:05,460 --> 00:19:08,120 Space Center launching from an equatorial site offers a significant 684 00:19:08,120 --> 00:19:08,130 equatorial site offers a significant 685 00:19:08,130 --> 00:19:10,370 equatorial site offers a significant advantage in payload weight capability 686 00:19:10,370 --> 00:19:10,380 advantage in payload weight capability 687 00:19:10,380 --> 00:19:12,650 advantage in payload weight capability and minimizes the amount of fuel needed 688 00:19:12,650 --> 00:19:12,660 and minimizes the amount of fuel needed 689 00:19:12,660 --> 00:19:17,750 and minimizes the amount of fuel needed to achieve an equatorial orbit since 690 00:19:17,750 --> 00:19:17,760 to achieve an equatorial orbit since 691 00:19:17,760 --> 00:19:20,240 to achieve an equatorial orbit since many satellites operate in equatorial 692 00:19:20,240 --> 00:19:20,250 many satellites operate in equatorial 693 00:19:20,250 --> 00:19:22,220 many satellites operate in equatorial orbits these are important 694 00:19:22,220 --> 00:19:22,230 orbits these are important 695 00:19:22,230 --> 00:19:29,780 orbits these are important considerations spacecraft are launched 696 00:19:29,780 --> 00:19:29,790 considerations spacecraft are launched 697 00:19:29,790 --> 00:19:32,000 considerations spacecraft are launched within a specified time interval called 698 00:19:32,000 --> 00:19:32,010 within a specified time interval called 699 00:19:32,010 --> 00:19:35,180 within a specified time interval called the launch window some of the factors 700 00:19:35,180 --> 00:19:35,190 the launch window some of the factors 701 00:19:35,190 --> 00:19:37,790 the launch window some of the factors affecting the launch window are launched 702 00:19:37,790 --> 00:19:37,800 affecting the launch window are launched 703 00:19:37,800 --> 00:19:43,990 affecting the launch window are launched in orbit lighting conditions Sun angles 704 00:19:43,990 --> 00:19:44,000 in orbit lighting conditions Sun angles 705 00:19:44,000 --> 00:19:49,010 in orbit lighting conditions Sun angles payload orbit requirements rendezvous 706 00:19:49,010 --> 00:19:49,020 payload orbit requirements rendezvous 707 00:19:49,020 --> 00:19:51,820 payload orbit requirements rendezvous phasing if a rendezvous is planned 708 00:19:51,820 --> 00:19:51,830 phasing if a rendezvous is planned 709 00:19:51,830 --> 00:19:54,500 phasing if a rendezvous is planned tracking and communication requirements 710 00:19:54,500 --> 00:19:54,510 tracking and communication requirements 711 00:19:54,510 --> 00:19:58,220 tracking and communication requirements and collision avoidance with other 712 00:19:58,220 --> 00:19:58,230 and collision avoidance with other 713 00:19:58,230 --> 00:20:01,420 and collision avoidance with other orbiting objects to name a few 714 00:20:01,420 --> 00:20:01,430 orbiting objects to name a few 715 00:20:01,430 --> 00:20:03,700 orbiting objects to name a few one of the factors defining the launch 716 00:20:03,700 --> 00:20:03,710 one of the factors defining the launch 717 00:20:03,710 --> 00:20:06,190 one of the factors defining the launch window for the Space Shuttle is launched 718 00:20:06,190 --> 00:20:06,200 window for the Space Shuttle is launched 719 00:20:06,200 --> 00:20:08,050 window for the Space Shuttle is launched lighting conditions which can be 720 00:20:08,050 --> 00:20:08,060 lighting conditions which can be 721 00:20:08,060 --> 00:20:10,810 lighting conditions which can be illustrated by plotting time versus day 722 00:20:10,810 --> 00:20:10,820 illustrated by plotting time versus day 723 00:20:10,820 --> 00:20:16,420 illustrated by plotting time versus day of year on this plot we see daylight and 724 00:20:16,420 --> 00:20:16,430 of year on this plot we see daylight and 725 00:20:16,430 --> 00:20:17,950 of year on this plot we see daylight and darkness at the launch site 726 00:20:17,950 --> 00:20:17,960 darkness at the launch site 727 00:20:17,960 --> 00:20:20,290 darkness at the launch site the longer daylight hours occur in the 728 00:20:20,290 --> 00:20:20,300 the longer daylight hours occur in the 729 00:20:20,300 --> 00:20:24,780 the longer daylight hours occur in the middle of the year summer time 730 00:20:24,780 --> 00:20:24,790 731 00:20:24,790 --> 00:20:27,940 if daylight conditions are required for 732 00:20:27,940 --> 00:20:27,950 if daylight conditions are required for 733 00:20:27,950 --> 00:20:30,340 if daylight conditions are required for a convenient emergency landing site for 734 00:20:30,340 --> 00:20:30,350 a convenient emergency landing site for 735 00:20:30,350 --> 00:20:32,200 a convenient emergency landing site for the space shuttle the launch window 736 00:20:32,200 --> 00:20:32,210 the space shuttle the launch window 737 00:20:32,210 --> 00:20:36,790 the space shuttle the launch window would now look like this during the 738 00:20:36,790 --> 00:20:36,800 would now look like this during the 739 00:20:36,800 --> 00:20:37,600 would now look like this during the winter months 740 00:20:37,600 --> 00:20:37,610 winter months 741 00:20:37,610 --> 00:20:39,430 winter months the available launch window for lighting 742 00:20:39,430 --> 00:20:39,440 the available launch window for lighting 743 00:20:39,440 --> 00:20:41,920 the available launch window for lighting conditions alone can be as little as 744 00:20:41,920 --> 00:20:41,930 conditions alone can be as little as 745 00:20:41,930 --> 00:20:44,620 conditions alone can be as little as three hours per day when combined with 746 00:20:44,620 --> 00:20:44,630 three hours per day when combined with 747 00:20:44,630 --> 00:20:47,080 three hours per day when combined with the many other launch factors the launch 748 00:20:47,080 --> 00:20:47,090 the many other launch factors the launch 749 00:20:47,090 --> 00:20:52,690 the many other launch factors the launch window becomes even more constrained the 750 00:20:52,690 --> 00:20:52,700 window becomes even more constrained the 751 00:20:52,700 --> 00:20:54,760 window becomes even more constrained the choice of a particular launch vehicle 752 00:20:54,760 --> 00:20:54,770 choice of a particular launch vehicle 753 00:20:54,770 --> 00:20:56,560 choice of a particular launch vehicle for a mission depends upon the weight 754 00:20:56,560 --> 00:20:56,570 for a mission depends upon the weight 755 00:20:56,570 --> 00:20:59,380 for a mission depends upon the weight and size of the payload and the desired 756 00:20:59,380 --> 00:20:59,390 and size of the payload and the desired 757 00:20:59,390 --> 00:21:04,270 and size of the payload and the desired orbit expendable rockets used to place 758 00:21:04,270 --> 00:21:04,280 orbit expendable rockets used to place 759 00:21:04,280 --> 00:21:06,880 orbit expendable rockets used to place spacecraft in orbit usually consist of 760 00:21:06,880 --> 00:21:06,890 spacecraft in orbit usually consist of 761 00:21:06,890 --> 00:21:09,520 spacecraft in orbit usually consist of several stages that may incorporate both 762 00:21:09,520 --> 00:21:09,530 several stages that may incorporate both 763 00:21:09,530 --> 00:21:11,410 several stages that may incorporate both solid and liquid propellants for 764 00:21:11,410 --> 00:21:11,420 solid and liquid propellants for 765 00:21:11,420 --> 00:21:14,260 solid and liquid propellants for propulsion when the fuel in each stage 766 00:21:14,260 --> 00:21:14,270 propulsion when the fuel in each stage 767 00:21:14,270 --> 00:21:16,450 propulsion when the fuel in each stage is depleted the spent stage is 768 00:21:16,450 --> 00:21:16,460 is depleted the spent stage is 769 00:21:16,460 --> 00:21:22,360 is depleted the spent stage is jettisoned staging offers the advantage 770 00:21:22,360 --> 00:21:22,370 jettisoned staging offers the advantage 771 00:21:22,370 --> 00:21:24,549 jettisoned staging offers the advantage of discarding weight when it is no 772 00:21:24,549 --> 00:21:24,559 of discarding weight when it is no 773 00:21:24,559 --> 00:21:28,630 of discarding weight when it is no longer needed the Space Shuttle is a 774 00:21:28,630 --> 00:21:28,640 longer needed the Space Shuttle is a 775 00:21:28,640 --> 00:21:31,810 longer needed the Space Shuttle is a two-stage system at liftoff the two 776 00:21:31,810 --> 00:21:31,820 two-stage system at liftoff the two 777 00:21:31,820 --> 00:21:34,150 two-stage system at liftoff the two solid rocket boosters and three Space 778 00:21:34,150 --> 00:21:34,160 solid rocket boosters and three Space 779 00:21:34,160 --> 00:21:36,850 solid rocket boosters and three Space Shuttle main engines are all producing 780 00:21:36,850 --> 00:21:36,860 Shuttle main engines are all producing 781 00:21:36,860 --> 00:21:40,570 Shuttle main engines are all producing thrust after approximately two minutes 782 00:21:40,570 --> 00:21:40,580 thrust after approximately two minutes 783 00:21:40,580 --> 00:21:44,650 thrust after approximately two minutes of flight at an altitude of 25 miles the 784 00:21:44,650 --> 00:21:44,660 of flight at an altitude of 25 miles the 785 00:21:44,660 --> 00:21:46,750 of flight at an altitude of 25 miles the fuel and the solid rocket boosters is 786 00:21:46,750 --> 00:21:46,760 fuel and the solid rocket boosters is 787 00:21:46,760 --> 00:21:49,230 fuel and the solid rocket boosters is depleted and they are jettisoned the 788 00:21:49,230 --> 00:21:49,240 depleted and they are jettisoned the 789 00:21:49,240 --> 00:21:52,120 depleted and they are jettisoned the three main engines fueled by liquid 790 00:21:52,120 --> 00:21:52,130 three main engines fueled by liquid 791 00:21:52,130 --> 00:21:54,460 three main engines fueled by liquid oxygen and liquid hydrogen carried in 792 00:21:54,460 --> 00:21:54,470 oxygen and liquid hydrogen carried in 793 00:21:54,470 --> 00:21:57,220 oxygen and liquid hydrogen carried in the external tank continue to burn for 794 00:21:57,220 --> 00:21:57,230 the external tank continue to burn for 795 00:21:57,230 --> 00:21:58,720 the external tank continue to burn for several minutes until the shuttle 796 00:21:58,720 --> 00:21:58,730 several minutes until the shuttle 797 00:21:58,730 --> 00:22:01,570 several minutes until the shuttle reaches its cutoff velocity at this time 798 00:22:01,570 --> 00:22:01,580 reaches its cutoff velocity at this time 799 00:22:01,580 --> 00:22:04,180 reaches its cutoff velocity at this time the main engines are shut down and the 800 00:22:04,180 --> 00:22:04,190 the main engines are shut down and the 801 00:22:04,190 --> 00:22:08,470 the main engines are shut down and the external tank is jettisoned to 802 00:22:08,470 --> 00:22:08,480 external tank is jettisoned to 803 00:22:08,480 --> 00:22:10,840 external tank is jettisoned to additional burns using the orbiters 804 00:22:10,840 --> 00:22:10,850 additional burns using the orbiters 805 00:22:10,850 --> 00:22:13,240 additional burns using the orbiters maneuvering system referred to as ohm's 806 00:22:13,240 --> 00:22:13,250 maneuvering system referred to as ohm's 807 00:22:13,250 --> 00:22:16,240 maneuvering system referred to as ohm's are required to place the orbiter in its 808 00:22:16,240 --> 00:22:16,250 are required to place the orbiter in its 809 00:22:16,250 --> 00:22:19,419 are required to place the orbiter in its final orbit the ohm's one burn occurs 810 00:22:19,419 --> 00:22:19,429 final orbit the ohm's one burn occurs 811 00:22:19,429 --> 00:22:21,640 final orbit the ohm's one burn occurs about two minutes after main engine 812 00:22:21,640 --> 00:22:21,650 about two minutes after main engine 813 00:22:21,650 --> 00:22:24,100 about two minutes after main engine shutdown and establishes the orbital 814 00:22:24,100 --> 00:22:24,110 shutdown and establishes the orbital 815 00:22:24,110 --> 00:22:27,340 shutdown and establishes the orbital Apogee point the ohms to burn takes 816 00:22:27,340 --> 00:22:27,350 Apogee point the ohms to burn takes 817 00:22:27,350 --> 00:22:29,880 Apogee point the ohms to burn takes place approximately 30 minutes later and 818 00:22:29,880 --> 00:22:29,890 place approximately 30 minutes later and 819 00:22:29,890 --> 00:22:36,010 place approximately 30 minutes later and circular eise's the orbit once 820 00:22:36,010 --> 00:22:36,020 circular eise's the orbit once 821 00:22:36,020 --> 00:22:37,840 circular eise's the orbit once satellites are launched and put into 822 00:22:37,840 --> 00:22:37,850 satellites are launched and put into 823 00:22:37,850 --> 00:22:38,380 satellites are launched and put into orbit 824 00:22:38,380 --> 00:22:38,390 orbit 825 00:22:38,390 --> 00:22:40,450 orbit it is often necessary to change the 826 00:22:40,450 --> 00:22:40,460 it is often necessary to change the 827 00:22:40,460 --> 00:22:44,380 it is often necessary to change the orbit with an on-orbit burn the common 828 00:22:44,380 --> 00:22:44,390 orbit with an on-orbit burn the common 829 00:22:44,390 --> 00:22:46,720 orbit with an on-orbit burn the common term used in describing on-orbit burns 830 00:22:46,720 --> 00:22:46,730 term used in describing on-orbit burns 831 00:22:46,730 --> 00:22:51,250 term used in describing on-orbit burns or engine firings is Delta V Delta V is 832 00:22:51,250 --> 00:22:51,260 or engine firings is Delta V Delta V is 833 00:22:51,260 --> 00:22:53,020 or engine firings is Delta V Delta V is the incremental change in spacecraft 834 00:22:53,020 --> 00:22:53,030 the incremental change in spacecraft 835 00:22:53,030 --> 00:22:55,810 the incremental change in spacecraft velocity measured in feet per second 836 00:22:55,810 --> 00:22:55,820 velocity measured in feet per second 837 00:22:55,820 --> 00:22:59,170 velocity measured in feet per second resulting from the burn the amount of 838 00:22:59,170 --> 00:22:59,180 resulting from the burn the amount of 839 00:22:59,180 --> 00:23:01,810 resulting from the burn the amount of fuel used during a burn depends on the 840 00:23:01,810 --> 00:23:01,820 fuel used during a burn depends on the 841 00:23:01,820 --> 00:23:04,570 fuel used during a burn depends on the desired Delta V change and the mass of 842 00:23:04,570 --> 00:23:04,580 desired Delta V change and the mass of 843 00:23:04,580 --> 00:23:06,880 desired Delta V change and the mass of the spacecraft because the amount of 844 00:23:06,880 --> 00:23:06,890 the spacecraft because the amount of 845 00:23:06,890 --> 00:23:09,730 the spacecraft because the amount of fuel carried is limited fuel consumption 846 00:23:09,730 --> 00:23:09,740 fuel carried is limited fuel consumption 847 00:23:09,740 --> 00:23:11,920 fuel carried is limited fuel consumption is one of the primary considerations in 848 00:23:11,920 --> 00:23:11,930 is one of the primary considerations in 849 00:23:11,930 --> 00:23:14,500 is one of the primary considerations in spacecraft mission planning and is 850 00:23:14,500 --> 00:23:14,510 spacecraft mission planning and is 851 00:23:14,510 --> 00:23:19,810 spacecraft mission planning and is critical to orbit lifetime on orbit a 852 00:23:19,810 --> 00:23:19,820 critical to orbit lifetime on orbit a 853 00:23:19,820 --> 00:23:22,330 critical to orbit lifetime on orbit a spacecraft can thrust in any direction 854 00:23:22,330 --> 00:23:22,340 spacecraft can thrust in any direction 855 00:23:22,340 --> 00:23:25,120 spacecraft can thrust in any direction burns along the flight path forward and 856 00:23:25,120 --> 00:23:25,130 burns along the flight path forward and 857 00:23:25,130 --> 00:23:28,540 burns along the flight path forward and backward are the most common a unique 858 00:23:28,540 --> 00:23:28,550 backward are the most common a unique 859 00:23:28,550 --> 00:23:31,090 backward are the most common a unique feature of any orbital burn is that if 860 00:23:31,090 --> 00:23:31,100 feature of any orbital burn is that if 861 00:23:31,100 --> 00:23:33,970 feature of any orbital burn is that if no other burns occur the spacecraft will 862 00:23:33,970 --> 00:23:33,980 no other burns occur the spacecraft will 863 00:23:33,980 --> 00:23:36,340 no other burns occur the spacecraft will later always pass again through the 864 00:23:36,340 --> 00:23:36,350 later always pass again through the 865 00:23:36,350 --> 00:23:40,750 later always pass again through the point of burn forward burns increase the 866 00:23:40,750 --> 00:23:40,760 point of burn forward burns increase the 867 00:23:40,760 --> 00:23:43,090 point of burn forward burns increase the spacecraft's velocity and are known as 868 00:23:43,090 --> 00:23:43,100 spacecraft's velocity and are known as 869 00:23:43,100 --> 00:23:47,500 spacecraft's velocity and are known as paws agreed burns with paws agreed burns 870 00:23:47,500 --> 00:23:47,510 paws agreed burns with paws agreed burns 871 00:23:47,510 --> 00:23:49,600 paws agreed burns with paws agreed burns the flight path of the vehicle will be 872 00:23:49,600 --> 00:23:49,610 the flight path of the vehicle will be 873 00:23:49,610 --> 00:23:52,210 the flight path of the vehicle will be raised at all points except the burn 874 00:23:52,210 --> 00:23:52,220 raised at all points except the burn 875 00:23:52,220 --> 00:23:56,260 raised at all points except the burn point burns opposite the direction of 876 00:23:56,260 --> 00:23:56,270 point burns opposite the direction of 877 00:23:56,270 --> 00:23:58,270 point burns opposite the direction of flight which slow the spacecraft down 878 00:23:58,270 --> 00:23:58,280 flight which slow the spacecraft down 879 00:23:58,280 --> 00:24:02,140 flight which slow the spacecraft down are called retrograde burns for 880 00:24:02,140 --> 00:24:02,150 are called retrograde burns for 881 00:24:02,150 --> 00:24:04,150 are called retrograde burns for retrograde burns the orbit will be 882 00:24:04,150 --> 00:24:04,160 retrograde burns the orbit will be 883 00:24:04,160 --> 00:24:06,340 retrograde burns the orbit will be lowered at all points except the burn 884 00:24:06,340 --> 00:24:06,350 lowered at all points except the burn 885 00:24:06,350 --> 00:24:09,490 lowered at all points except the burn point the greater the Delta V the 886 00:24:09,490 --> 00:24:09,500 point the greater the Delta V the 887 00:24:09,500 --> 00:24:11,320 point the greater the Delta V the greater the difference between the pre 888 00:24:11,320 --> 00:24:11,330 greater the difference between the pre 889 00:24:11,330 --> 00:24:16,130 greater the difference between the pre burn and post burn orbits 890 00:24:16,130 --> 00:24:16,140 891 00:24:16,140 --> 00:24:18,770 burns can be combined into maneuver 892 00:24:18,770 --> 00:24:18,780 burns can be combined into maneuver 893 00:24:18,780 --> 00:24:21,820 burns can be combined into maneuver sequences to change orbits size shape or 894 00:24:21,820 --> 00:24:21,830 sequences to change orbits size shape or 895 00:24:21,830 --> 00:24:24,740 sequences to change orbits size shape or orientation one of the most common 896 00:24:24,740 --> 00:24:24,750 orientation one of the most common 897 00:24:24,750 --> 00:24:26,960 orientation one of the most common maneuver sequences is made up of two 898 00:24:26,960 --> 00:24:26,970 maneuver sequences is made up of two 899 00:24:26,970 --> 00:24:29,750 maneuver sequences is made up of two burns and is used to accomplish an orbit 900 00:24:29,750 --> 00:24:29,760 burns and is used to accomplish an orbit 901 00:24:29,760 --> 00:24:32,660 burns and is used to accomplish an orbit transfer between two circular orbits in 902 00:24:32,660 --> 00:24:32,670 transfer between two circular orbits in 903 00:24:32,670 --> 00:24:36,380 transfer between two circular orbits in the same orbital plane the most energy 904 00:24:36,380 --> 00:24:36,390 the same orbital plane the most energy 905 00:24:36,390 --> 00:24:38,960 the same orbital plane the most energy efficient transfer between two orbits of 906 00:24:38,960 --> 00:24:38,970 efficient transfer between two orbits of 907 00:24:38,970 --> 00:24:43,250 efficient transfer between two orbits of this type is the Hohmann transfer the 908 00:24:43,250 --> 00:24:43,260 this type is the Hohmann transfer the 909 00:24:43,260 --> 00:24:45,830 this type is the Hohmann transfer the Hohmann transfer is actually one half of 910 00:24:45,830 --> 00:24:45,840 Hohmann transfer is actually one half of 911 00:24:45,840 --> 00:24:48,260 Hohmann transfer is actually one half of an elliptical orbit with its perigee in 912 00:24:48,260 --> 00:24:48,270 an elliptical orbit with its perigee in 913 00:24:48,270 --> 00:24:50,900 an elliptical orbit with its perigee in one of the orbits at its Apogee in the 914 00:24:50,900 --> 00:24:50,910 one of the orbits at its Apogee in the 915 00:24:50,910 --> 00:24:54,020 one of the orbits at its Apogee in the other the burns occur at the perigee and 916 00:24:54,020 --> 00:24:54,030 other the burns occur at the perigee and 917 00:24:54,030 --> 00:24:58,190 other the burns occur at the perigee and Apogee of the transfer orbit the use of 918 00:24:58,190 --> 00:24:58,200 Apogee of the transfer orbit the use of 919 00:24:58,200 --> 00:25:00,530 Apogee of the transfer orbit the use of the Hohmann transfer minimizes the Delta 920 00:25:00,530 --> 00:25:00,540 the Hohmann transfer minimizes the Delta 921 00:25:00,540 --> 00:25:03,140 the Hohmann transfer minimizes the Delta V required thus having the advantage of 922 00:25:03,140 --> 00:25:03,150 V required thus having the advantage of 923 00:25:03,150 --> 00:25:06,560 V required thus having the advantage of using minimum fuel the disadvantage of 924 00:25:06,560 --> 00:25:06,570 using minimum fuel the disadvantage of 925 00:25:06,570 --> 00:25:08,600 using minimum fuel the disadvantage of the Hohmann transfer is that it takes 926 00:25:08,600 --> 00:25:08,610 the Hohmann transfer is that it takes 927 00:25:08,610 --> 00:25:12,409 the Hohmann transfer is that it takes longer than most other transfers the 928 00:25:12,409 --> 00:25:12,419 longer than most other transfers the 929 00:25:12,419 --> 00:25:14,750 longer than most other transfers the type of the transfer sequence depends on 930 00:25:14,750 --> 00:25:14,760 type of the transfer sequence depends on 931 00:25:14,760 --> 00:25:16,520 type of the transfer sequence depends on the mission and the amount of fuel 932 00:25:16,520 --> 00:25:16,530 the mission and the amount of fuel 933 00:25:16,530 --> 00:25:20,480 the mission and the amount of fuel available for example a space rescue 934 00:25:20,480 --> 00:25:20,490 available for example a space rescue 935 00:25:20,490 --> 00:25:23,210 available for example a space rescue where time is critical might use a fast 936 00:25:23,210 --> 00:25:23,220 where time is critical might use a fast 937 00:25:23,220 --> 00:25:25,640 where time is critical might use a fast transfer while a routine satellite 938 00:25:25,640 --> 00:25:25,650 transfer while a routine satellite 939 00:25:25,650 --> 00:25:28,010 transfer while a routine satellite deployment where fuel saved for later 940 00:25:28,010 --> 00:25:28,020 deployment where fuel saved for later 941 00:25:28,020 --> 00:25:30,620 deployment where fuel saved for later use is important would most likely use a 942 00:25:30,620 --> 00:25:30,630 use is important would most likely use a 943 00:25:30,630 --> 00:25:35,299 use is important would most likely use a Hohmann transfer the burns discussed so 944 00:25:35,299 --> 00:25:35,309 Hohmann transfer the burns discussed so 945 00:25:35,309 --> 00:25:37,250 Hohmann transfer the burns discussed so far have all been maneuvering in the 946 00:25:37,250 --> 00:25:37,260 far have all been maneuvering in the 947 00:25:37,260 --> 00:25:39,770 far have all been maneuvering in the original orbital plane and do not affect 948 00:25:39,770 --> 00:25:39,780 original orbital plane and do not affect 949 00:25:39,780 --> 00:25:43,620 original orbital plane and do not affect orbit inclination or node position 950 00:25:43,620 --> 00:25:43,630 orbit inclination or node position 951 00:25:43,630 --> 00:25:46,529 orbit inclination or node position there are situations which require an 952 00:25:46,529 --> 00:25:46,539 there are situations which require an 953 00:25:46,539 --> 00:25:49,049 there are situations which require an orbital plane change such as setting up 954 00:25:49,049 --> 00:25:49,059 orbital plane change such as setting up 955 00:25:49,059 --> 00:25:51,480 orbital plane change such as setting up a rendezvous or placing a satellite in 956 00:25:51,480 --> 00:25:51,490 a rendezvous or placing a satellite in 957 00:25:51,490 --> 00:25:54,900 a rendezvous or placing a satellite in an equatorial orbit to change the 958 00:25:54,900 --> 00:25:54,910 an equatorial orbit to change the 959 00:25:54,910 --> 00:25:57,270 an equatorial orbit to change the inclination the thrust vector must be 960 00:25:57,270 --> 00:25:57,280 inclination the thrust vector must be 961 00:25:57,280 --> 00:25:59,430 inclination the thrust vector must be directed at an angle to the orbital 962 00:25:59,430 --> 00:25:59,440 directed at an angle to the orbital 963 00:25:59,440 --> 00:26:03,360 directed at an angle to the orbital plane a thrust with a component that is 964 00:26:03,360 --> 00:26:03,370 plane a thrust with a component that is 965 00:26:03,370 --> 00:26:05,640 plane a thrust with a component that is perpendicular to the orbital plane at 966 00:26:05,640 --> 00:26:05,650 perpendicular to the orbital plane at 967 00:26:05,650 --> 00:26:08,370 perpendicular to the orbital plane at either the ascending or descending node 968 00:26:08,370 --> 00:26:08,380 either the ascending or descending node 969 00:26:08,380 --> 00:26:11,190 either the ascending or descending node will rotate the orbital plane about the 970 00:26:11,190 --> 00:26:11,200 will rotate the orbital plane about the 971 00:26:11,200 --> 00:26:12,620 will rotate the orbital plane about the line of nodes 972 00:26:12,620 --> 00:26:12,630 line of nodes 973 00:26:12,630 --> 00:26:15,029 line of nodes Northerly out of plane thrust at the 974 00:26:15,029 --> 00:26:15,039 Northerly out of plane thrust at the 975 00:26:15,039 --> 00:26:17,190 Northerly out of plane thrust at the ascending node will increase the 976 00:26:17,190 --> 00:26:17,200 ascending node will increase the 977 00:26:17,200 --> 00:26:19,710 ascending node will increase the inclination of a pro-grade orbit while a 978 00:26:19,710 --> 00:26:19,720 inclination of a pro-grade orbit while a 979 00:26:19,720 --> 00:26:24,180 inclination of a pro-grade orbit while a southerly thrust will decrease it out of 980 00:26:24,180 --> 00:26:24,190 southerly thrust will decrease it out of 981 00:26:24,190 --> 00:26:26,370 southerly thrust will decrease it out of plane thrusts require considerable 982 00:26:26,370 --> 00:26:26,380 plane thrusts require considerable 983 00:26:26,380 --> 00:26:28,590 plane thrusts require considerable amounts of fuel and are performed only 984 00:26:28,590 --> 00:26:28,600 amounts of fuel and are performed only 985 00:26:28,600 --> 00:26:35,700 amounts of fuel and are performed only when absolutely required the Space 986 00:26:35,700 --> 00:26:35,710 when absolutely required the Space 987 00:26:35,710 --> 00:26:37,680 when absolutely required the Space Shuttle for example using all of its 988 00:26:37,680 --> 00:26:37,690 Shuttle for example using all of its 989 00:26:37,690 --> 00:26:40,289 Shuttle for example using all of its onboard propellant is capable of an 990 00:26:40,289 --> 00:26:40,299 onboard propellant is capable of an 991 00:26:40,299 --> 00:26:43,080 onboard propellant is capable of an on-orbit plane change of less than three 992 00:26:43,080 --> 00:26:43,090 on-orbit plane change of less than three 993 00:26:43,090 --> 00:26:47,850 on-orbit plane change of less than three degrees 994 00:26:47,850 --> 00:26:47,860 995 00:26:47,860 --> 00:26:50,680 satellite orbital planes and altitudes 996 00:26:50,680 --> 00:26:50,690 satellite orbital planes and altitudes 997 00:26:50,690 --> 00:26:53,049 satellite orbital planes and altitudes are determined by their design mission 998 00:26:53,049 --> 00:26:53,059 are determined by their design mission 999 00:26:53,059 --> 00:26:55,540 are determined by their design mission which very often includes a field of 1000 00:26:55,540 --> 00:26:55,550 which very often includes a field of 1001 00:26:55,550 --> 00:26:57,640 which very often includes a field of view requirement for optical or 1002 00:26:57,640 --> 00:26:57,650 view requirement for optical or 1003 00:26:57,650 --> 00:27:00,790 view requirement for optical or communications purposes the field of 1004 00:27:00,790 --> 00:27:00,800 communications purposes the field of 1005 00:27:00,800 --> 00:27:03,070 communications purposes the field of view of a satellite is defined as the 1006 00:27:03,070 --> 00:27:03,080 view of a satellite is defined as the 1007 00:27:03,080 --> 00:27:05,590 view of a satellite is defined as the area of the Earth's surface that is in 1008 00:27:05,590 --> 00:27:05,600 area of the Earth's surface that is in 1009 00:27:05,600 --> 00:27:07,660 area of the Earth's surface that is in view from the satellite at any given 1010 00:27:07,660 --> 00:27:07,670 view from the satellite at any given 1011 00:27:07,670 --> 00:27:11,200 view from the satellite at any given time satellites in high orbits have 1012 00:27:11,200 --> 00:27:11,210 time satellites in high orbits have 1013 00:27:11,210 --> 00:27:13,390 time satellites in high orbits have greater fields of view than those in 1014 00:27:13,390 --> 00:27:13,400 greater fields of view than those in 1015 00:27:13,400 --> 00:27:16,900 greater fields of view than those in lower orbits for example a satellite at 1016 00:27:16,900 --> 00:27:16,910 lower orbits for example a satellite at 1017 00:27:16,910 --> 00:27:19,570 lower orbits for example a satellite at an altitude of 800 nautical miles has a 1018 00:27:19,570 --> 00:27:19,580 an altitude of 800 nautical miles has a 1019 00:27:19,580 --> 00:27:21,760 an altitude of 800 nautical miles has a circular field of view with a diameter 1020 00:27:21,760 --> 00:27:21,770 circular field of view with a diameter 1021 00:27:21,770 --> 00:27:26,100 circular field of view with a diameter of about 40 100 nautical miles a 1022 00:27:26,100 --> 00:27:26,110 of about 40 100 nautical miles a 1023 00:27:26,110 --> 00:27:29,049 of about 40 100 nautical miles a satellite at 200 nautical miles has a 1024 00:27:29,049 --> 00:27:29,059 satellite at 200 nautical miles has a 1025 00:27:29,059 --> 00:27:31,240 satellite at 200 nautical miles has a circular field of view with a diameter 1026 00:27:31,240 --> 00:27:31,250 circular field of view with a diameter 1027 00:27:31,250 --> 00:27:35,290 circular field of view with a diameter of about 2,000 nautical miles low orbit 1028 00:27:35,290 --> 00:27:35,300 of about 2,000 nautical miles low orbit 1029 00:27:35,300 --> 00:27:37,150 of about 2,000 nautical miles low orbit satellites are often used for 1030 00:27:37,150 --> 00:27:37,160 satellites are often used for 1031 00:27:37,160 --> 00:27:39,370 satellites are often used for photography and other types of Earth 1032 00:27:39,370 --> 00:27:39,380 photography and other types of Earth 1033 00:27:39,380 --> 00:27:43,510 photography and other types of Earth observation a satellite placed in a low 1034 00:27:43,510 --> 00:27:43,520 observation a satellite placed in a low 1035 00:27:43,520 --> 00:27:45,580 observation a satellite placed in a low inclination circular orbit at an 1036 00:27:45,580 --> 00:27:45,590 inclination circular orbit at an 1037 00:27:45,590 --> 00:27:48,700 inclination circular orbit at an altitude of about 19,000 300 nautical 1038 00:27:48,700 --> 00:27:48,710 altitude of about 19,000 300 nautical 1039 00:27:48,710 --> 00:27:51,299 altitude of about 19,000 300 nautical miles will have an angular velocity 1040 00:27:51,299 --> 00:27:51,309 miles will have an angular velocity 1041 00:27:51,309 --> 00:27:55,720 miles will have an angular velocity exactly equal to that of the earth the 1042 00:27:55,720 --> 00:27:55,730 exactly equal to that of the earth the 1043 00:27:55,730 --> 00:27:57,250 exactly equal to that of the earth the satellite would seem to remain 1044 00:27:57,250 --> 00:27:57,260 satellite would seem to remain 1045 00:27:57,260 --> 00:27:59,919 satellite would seem to remain stationary in longitude as viewed from 1046 00:27:59,919 --> 00:27:59,929 stationary in longitude as viewed from 1047 00:27:59,929 --> 00:28:02,799 stationary in longitude as viewed from the ground such orbits are called 1048 00:28:02,799 --> 00:28:02,809 the ground such orbits are called 1049 00:28:02,809 --> 00:28:05,350 the ground such orbits are called geosynchronous and are used to provide a 1050 00:28:05,350 --> 00:28:05,360 geosynchronous and are used to provide a 1051 00:28:05,360 --> 00:28:07,690 geosynchronous and are used to provide a continuous communications capability 1052 00:28:07,690 --> 00:28:07,700 continuous communications capability 1053 00:28:07,700 --> 00:28:09,760 continuous communications capability among any system of ground stations 1054 00:28:09,760 --> 00:28:09,770 among any system of ground stations 1055 00:28:09,770 --> 00:28:12,850 among any system of ground stations within their field of view the 1056 00:28:12,850 --> 00:28:12,860 within their field of view the 1057 00:28:12,860 --> 00:28:15,190 within their field of view the geosynchronous orbit field of view is 1058 00:28:15,190 --> 00:28:15,200 geosynchronous orbit field of view is 1059 00:28:15,200 --> 00:28:17,530 geosynchronous orbit field of view is constant and is limited to a latitude 1060 00:28:17,530 --> 00:28:17,540 constant and is limited to a latitude 1061 00:28:17,540 --> 00:28:20,020 constant and is limited to a latitude zone of about 70 degrees north and south 1062 00:28:20,020 --> 00:28:20,030 zone of about 70 degrees north and south 1063 00:28:20,030 --> 00:28:23,560 zone of about 70 degrees north and south of the equator effective satellite 1064 00:28:23,560 --> 00:28:23,570 of the equator effective satellite 1065 00:28:23,570 --> 00:28:25,810 of the equator effective satellite communications from geosynchronous orbit 1066 00:28:25,810 --> 00:28:25,820 communications from geosynchronous orbit 1067 00:28:25,820 --> 00:28:29,500 communications from geosynchronous orbit is not possible at either Pole however 1068 00:28:29,500 --> 00:28:29,510 is not possible at either Pole however 1069 00:28:29,510 --> 00:28:32,080 is not possible at either Pole however because of their altitude their field of 1070 00:28:32,080 --> 00:28:32,090 because of their altitude their field of 1071 00:28:32,090 --> 00:28:34,890 because of their altitude their field of view covers nearly half the globe a 1072 00:28:34,890 --> 00:28:34,900 view covers nearly half the globe a 1073 00:28:34,900 --> 00:28:37,660 view covers nearly half the globe a special type of geosynchronous orbit 1074 00:28:37,660 --> 00:28:37,670 special type of geosynchronous orbit 1075 00:28:37,670 --> 00:28:40,090 special type of geosynchronous orbit with an inclination of 0 degrees is 1076 00:28:40,090 --> 00:28:40,100 with an inclination of 0 degrees is 1077 00:28:40,100 --> 00:28:45,790 with an inclination of 0 degrees is called a geostationary orbit it appears 1078 00:28:45,790 --> 00:28:45,800 called a geostationary orbit it appears 1079 00:28:45,800 --> 00:28:47,890 called a geostationary orbit it appears to hover over a fixed point on the 1080 00:28:47,890 --> 00:28:47,900 to hover over a fixed point on the 1081 00:28:47,900 --> 00:28:51,019 to hover over a fixed point on the Earth's surface at the equator 1082 00:28:51,019 --> 00:28:51,029 Earth's surface at the equator 1083 00:28:51,029 --> 00:28:54,060 Earth's surface at the equator most us communication satellites are in 1084 00:28:54,060 --> 00:28:54,070 most us communication satellites are in 1085 00:28:54,070 --> 00:28:56,700 most us communication satellites are in geosynchronous orbits providing near 1086 00:28:56,700 --> 00:28:56,710 geosynchronous orbits providing near 1087 00:28:56,710 --> 00:29:01,169 geosynchronous orbits providing near worldwide communications coverage for 1088 00:29:01,169 --> 00:29:01,179 worldwide communications coverage for 1089 00:29:01,179 --> 00:29:03,029 worldwide communications coverage for effective communications at high 1090 00:29:03,029 --> 00:29:03,039 effective communications at high 1091 00:29:03,039 --> 00:29:06,680 effective communications at high latitudes the molniya orbit is used 1092 00:29:06,680 --> 00:29:06,690 latitudes the molniya orbit is used 1093 00:29:06,690 --> 00:29:09,510 latitudes the molniya orbit is used mahlia is the Russian word for lightning 1094 00:29:09,510 --> 00:29:09,520 mahlia is the Russian word for lightning 1095 00:29:09,520 --> 00:29:12,330 mahlia is the Russian word for lightning and is an orbit used extensively by the 1096 00:29:12,330 --> 00:29:12,340 and is an orbit used extensively by the 1097 00:29:12,340 --> 00:29:14,639 and is an orbit used extensively by the Soviet Union for its communication 1098 00:29:14,639 --> 00:29:14,649 Soviet Union for its communication 1099 00:29:14,649 --> 00:29:18,060 Soviet Union for its communication satellites pneumoniae orbit is highly 1100 00:29:18,060 --> 00:29:18,070 satellites pneumoniae orbit is highly 1101 00:29:18,070 --> 00:29:20,490 satellites pneumoniae orbit is highly eccentric with an Apogee that is near 1102 00:29:20,490 --> 00:29:20,500 eccentric with an Apogee that is near 1103 00:29:20,500 --> 00:29:23,039 eccentric with an Apogee that is near the geosynchronous altitude and an 1104 00:29:23,039 --> 00:29:23,049 the geosynchronous altitude and an 1105 00:29:23,049 --> 00:29:28,560 the geosynchronous altitude and an inclination of about 63 degrees the 1106 00:29:28,560 --> 00:29:28,570 inclination of about 63 degrees the 1107 00:29:28,570 --> 00:29:30,810 inclination of about 63 degrees the satellite slows down at Apogee in the 1108 00:29:30,810 --> 00:29:30,820 satellite slows down at Apogee in the 1109 00:29:30,820 --> 00:29:32,760 satellite slows down at Apogee in the northern hemisphere and whips through 1110 00:29:32,760 --> 00:29:32,770 northern hemisphere and whips through 1111 00:29:32,770 --> 00:29:36,570 northern hemisphere and whips through perigee in the southern hemisphere this 1112 00:29:36,570 --> 00:29:36,580 perigee in the southern hemisphere this 1113 00:29:36,580 --> 00:29:38,580 perigee in the southern hemisphere this provides communications in the northern 1114 00:29:38,580 --> 00:29:38,590 provides communications in the northern 1115 00:29:38,590 --> 00:29:41,880 provides communications in the northern hemisphere for up to 75% of its orbital 1116 00:29:41,880 --> 00:29:41,890 hemisphere for up to 75% of its orbital 1117 00:29:41,890 --> 00:29:45,690 hemisphere for up to 75% of its orbital period several satellites properly 1118 00:29:45,690 --> 00:29:45,700 period several satellites properly 1119 00:29:45,700 --> 00:29:48,090 period several satellites properly spaced in molniya orbits can provide 1120 00:29:48,090 --> 00:29:48,100 spaced in molniya orbits can provide 1121 00:29:48,100 --> 00:29:50,610 spaced in molniya orbits can provide constant communications at the northern 1122 00:29:50,610 --> 00:29:50,620 constant communications at the northern 1123 00:29:50,620 --> 00:29:55,740 constant communications at the northern latitudes navigation satellites such as 1124 00:29:55,740 --> 00:29:55,750 latitudes navigation satellites such as 1125 00:29:55,750 --> 00:29:58,200 latitudes navigation satellites such as the US Navy's transit system and the 1126 00:29:58,200 --> 00:29:58,210 the US Navy's transit system and the 1127 00:29:58,210 --> 00:30:01,260 the US Navy's transit system and the joint service Navstar GPS Global 1128 00:30:01,260 --> 00:30:01,270 joint service Navstar GPS Global 1129 00:30:01,270 --> 00:30:04,200 joint service Navstar GPS Global Positioning System use lower orbits so 1130 00:30:04,200 --> 00:30:04,210 Positioning System use lower orbits so 1131 00:30:04,210 --> 00:30:06,450 Positioning System use lower orbits so that a user can receive signals from 1132 00:30:06,450 --> 00:30:06,460 that a user can receive signals from 1133 00:30:06,460 --> 00:30:10,130 that a user can receive signals from more than one satellite at any time 1134 00:30:10,130 --> 00:30:10,140 more than one satellite at any time 1135 00:30:10,140 --> 00:30:13,049 more than one satellite at any time another frequently used orbit is known 1136 00:30:13,049 --> 00:30:13,059 another frequently used orbit is known 1137 00:30:13,059 --> 00:30:16,769 another frequently used orbit is known as a sun-synchronous orbit these take 1138 00:30:16,769 --> 00:30:16,779 as a sun-synchronous orbit these take 1139 00:30:16,779 --> 00:30:18,389 as a sun-synchronous orbit these take advantage of the precession of the 1140 00:30:18,389 --> 00:30:18,399 advantage of the precession of the 1141 00:30:18,399 --> 00:30:21,000 advantage of the precession of the orbital plane caused by the earth not 1142 00:30:21,000 --> 00:30:21,010 orbital plane caused by the earth not 1143 00:30:21,010 --> 00:30:23,909 orbital plane caused by the earth not being a perfect sphere all Sun 1144 00:30:23,909 --> 00:30:23,919 being a perfect sphere all Sun 1145 00:30:23,919 --> 00:30:25,980 being a perfect sphere all Sun synchronous orbits are highly inclined 1146 00:30:25,980 --> 00:30:25,990 synchronous orbits are highly inclined 1147 00:30:25,990 --> 00:30:28,740 synchronous orbits are highly inclined retrograde orbits which precess eastward 1148 00:30:28,740 --> 00:30:28,750 retrograde orbits which precess eastward 1149 00:30:28,750 --> 00:30:30,990 retrograde orbits which precess eastward around the Earth's polar axis at the 1150 00:30:30,990 --> 00:30:31,000 around the Earth's polar axis at the 1151 00:30:31,000 --> 00:30:34,409 around the Earth's polar axis at the rate of one revolution per year since 1152 00:30:34,409 --> 00:30:34,419 rate of one revolution per year since 1153 00:30:34,419 --> 00:30:36,659 rate of one revolution per year since the Earth's Sun line also revolves 1154 00:30:36,659 --> 00:30:36,669 the Earth's Sun line also revolves 1155 00:30:36,669 --> 00:30:38,460 the Earth's Sun line also revolves eastward of the rate of one revolution 1156 00:30:38,460 --> 00:30:38,470 eastward of the rate of one revolution 1157 00:30:38,470 --> 00:30:40,680 eastward of the rate of one revolution per year the orbital plane will maintain 1158 00:30:40,680 --> 00:30:40,690 per year the orbital plane will maintain 1159 00:30:40,690 --> 00:30:43,500 per year the orbital plane will maintain a constant orientation relative to the 1160 00:30:43,500 --> 00:30:43,510 a constant orientation relative to the 1161 00:30:43,510 --> 00:30:48,389 a constant orientation relative to the Earth's Sun line if the satellites 1162 00:30:48,389 --> 00:30:48,399 Earth's Sun line if the satellites 1163 00:30:48,399 --> 00:30:50,610 Earth's Sun line if the satellites period is then synchronized with the 1164 00:30:50,610 --> 00:30:50,620 period is then synchronized with the 1165 00:30:50,620 --> 00:30:53,310 period is then synchronized with the rotation of the earth it will pass over 1166 00:30:53,310 --> 00:30:53,320 rotation of the earth it will pass over 1167 00:30:53,320 --> 00:30:55,470 rotation of the earth it will pass over the same point on the Earth's surface at 1168 00:30:55,470 --> 00:30:55,480 the same point on the Earth's surface at 1169 00:30:55,480 --> 00:30:58,169 the same point on the Earth's surface at the same local time at a regular 1170 00:30:58,169 --> 00:30:58,179 the same local time at a regular 1171 00:30:58,179 --> 00:31:01,550 the same local time at a regular interval 1172 00:31:01,550 --> 00:31:01,560 1173 00:31:01,560 --> 00:31:04,400 a sun-synchronous satellite ensures that 1174 00:31:04,400 --> 00:31:04,410 a sun-synchronous satellite ensures that 1175 00:31:04,410 --> 00:31:06,920 a sun-synchronous satellite ensures that a constant sun angle and uniform 1176 00:31:06,920 --> 00:31:06,930 a constant sun angle and uniform 1177 00:31:06,930 --> 00:31:09,410 a constant sun angle and uniform lighting exist for the same field of 1178 00:31:09,410 --> 00:31:09,420 lighting exist for the same field of 1179 00:31:09,420 --> 00:31:13,760 lighting exist for the same field of view from past to pass satellites such 1180 00:31:13,760 --> 00:31:13,770 view from past to pass satellites such 1181 00:31:13,770 --> 00:31:16,010 view from past to pass satellites such as those in the defense meteorological 1182 00:31:16,010 --> 00:31:16,020 as those in the defense meteorological 1183 00:31:16,020 --> 00:31:18,980 as those in the defense meteorological satellite program and Landsat our Sun 1184 00:31:18,980 --> 00:31:18,990 satellite program and Landsat our Sun 1185 00:31:18,990 --> 00:31:21,680 satellite program and Landsat our Sun synchronous imaging the entire Earth on 1186 00:31:21,680 --> 00:31:21,690 synchronous imaging the entire Earth on 1187 00:31:21,690 --> 00:31:27,650 synchronous imaging the entire Earth on a regular schedule 1188 00:31:27,650 --> 00:31:27,660 1189 00:31:27,660 --> 00:31:30,390 the gravitational attraction of the 1190 00:31:30,390 --> 00:31:30,400 the gravitational attraction of the 1191 00:31:30,400 --> 00:31:32,880 the gravitational attraction of the earth on a spacecraft causes it to move 1192 00:31:32,880 --> 00:31:32,890 earth on a spacecraft causes it to move 1193 00:31:32,890 --> 00:31:36,870 earth on a spacecraft causes it to move in its orbit around the Earth there are 1194 00:31:36,870 --> 00:31:36,880 in its orbit around the Earth there are 1195 00:31:36,880 --> 00:31:39,030 in its orbit around the Earth there are other much smaller forces which will 1196 00:31:39,030 --> 00:31:39,040 other much smaller forces which will 1197 00:31:39,040 --> 00:31:41,220 other much smaller forces which will cause a spacecraft to deviate from its 1198 00:31:41,220 --> 00:31:41,230 cause a spacecraft to deviate from its 1199 00:31:41,230 --> 00:31:44,400 cause a spacecraft to deviate from its desired orbit these forces cause what 1200 00:31:44,400 --> 00:31:44,410 desired orbit these forces cause what 1201 00:31:44,410 --> 00:31:47,780 desired orbit these forces cause what are known as orbital perturbations 1202 00:31:47,780 --> 00:31:47,790 1203 00:31:47,790 --> 00:31:50,280 orbital precession which is used to 1204 00:31:50,280 --> 00:31:50,290 orbital precession which is used to 1205 00:31:50,290 --> 00:31:52,800 orbital precession which is used to obtain Sun synchronous orbits results 1206 00:31:52,800 --> 00:31:52,810 obtain Sun synchronous orbits results 1207 00:31:52,810 --> 00:31:54,480 obtain Sun synchronous orbits results from the perturbing effects of the 1208 00:31:54,480 --> 00:31:54,490 from the perturbing effects of the 1209 00:31:54,490 --> 00:31:58,110 from the perturbing effects of the Earth's non spherical shape other 1210 00:31:58,110 --> 00:31:58,120 Earth's non spherical shape other 1211 00:31:58,120 --> 00:32:01,020 Earth's non spherical shape other perturbing forces are the gravitational 1212 00:32:01,020 --> 00:32:01,030 perturbing forces are the gravitational 1213 00:32:01,030 --> 00:32:07,790 perturbing forces are the gravitational pull of the Sun the moon and planets and 1214 00:32:07,790 --> 00:32:07,800 pull of the Sun the moon and planets and 1215 00:32:07,800 --> 00:32:11,520 pull of the Sun the moon and planets and solar winds which are charged streams of 1216 00:32:11,520 --> 00:32:11,530 solar winds which are charged streams of 1217 00:32:11,530 --> 00:32:13,710 solar winds which are charged streams of protons and electrons that heat the 1218 00:32:13,710 --> 00:32:13,720 protons and electrons that heat the 1219 00:32:13,720 --> 00:32:15,450 protons and electrons that heat the Earth's atmosphere and increase 1220 00:32:15,450 --> 00:32:15,460 Earth's atmosphere and increase 1221 00:32:15,460 --> 00:32:20,490 Earth's atmosphere and increase atmospheric drag in most cases 1222 00:32:20,490 --> 00:32:20,500 atmospheric drag in most cases 1223 00:32:20,500 --> 00:32:22,830 atmospheric drag in most cases perturbing forces can be compensated for 1224 00:32:22,830 --> 00:32:22,840 perturbing forces can be compensated for 1225 00:32:22,840 --> 00:32:25,650 perturbing forces can be compensated for in the spacecraft and orbit design and 1226 00:32:25,650 --> 00:32:25,660 in the spacecraft and orbit design and 1227 00:32:25,660 --> 00:32:29,760 in the spacecraft and orbit design and present no major problems if the forces 1228 00:32:29,760 --> 00:32:29,770 present no major problems if the forces 1229 00:32:29,770 --> 00:32:32,520 present no major problems if the forces disturb the orbit too much thrusters can 1230 00:32:32,520 --> 00:32:32,530 disturb the orbit too much thrusters can 1231 00:32:32,530 --> 00:32:34,650 disturb the orbit too much thrusters can be fired to re-establish its desired 1232 00:32:34,650 --> 00:32:34,660 be fired to re-establish its desired 1233 00:32:34,660 --> 00:32:39,480 be fired to re-establish its desired orbital orientation or altitude this is 1234 00:32:39,480 --> 00:32:39,490 orbital orientation or altitude this is 1235 00:32:39,490 --> 00:32:41,550 orbital orientation or altitude this is particularly true for spacecraft 1236 00:32:41,550 --> 00:32:41,560 particularly true for spacecraft 1237 00:32:41,560 --> 00:32:44,190 particularly true for spacecraft orbiting at very low altitudes where the 1238 00:32:44,190 --> 00:32:44,200 orbiting at very low altitudes where the 1239 00:32:44,200 --> 00:32:46,560 orbiting at very low altitudes where the effects of atmospheric drag are greater 1240 00:32:46,560 --> 00:32:46,570 effects of atmospheric drag are greater 1241 00:32:46,570 --> 00:32:49,170 effects of atmospheric drag are greater and if not compensated for will 1242 00:32:49,170 --> 00:32:49,180 and if not compensated for will 1243 00:32:49,180 --> 00:32:51,000 and if not compensated for will eventually cause the spacecraft to 1244 00:32:51,000 --> 00:32:51,010 eventually cause the spacecraft to 1245 00:32:51,010 --> 00:32:54,750 eventually cause the spacecraft to deorbit a spacecrafts operational 1246 00:32:54,750 --> 00:32:54,760 deorbit a spacecrafts operational 1247 00:32:54,760 --> 00:32:57,090 deorbit a spacecrafts operational lifetime is frequently limited only by 1248 00:32:57,090 --> 00:32:57,100 lifetime is frequently limited only by 1249 00:32:57,100 --> 00:32:59,730 lifetime is frequently limited only by the amount of fuel available to maintain 1250 00:32:59,730 --> 00:32:59,740 the amount of fuel available to maintain 1251 00:32:59,740 --> 00:33:03,420 the amount of fuel available to maintain its desired orbit when its useful life 1252 00:33:03,420 --> 00:33:03,430 its desired orbit when its useful life 1253 00:33:03,430 --> 00:33:06,390 its desired orbit when its useful life is complete a satellite is left in orbit 1254 00:33:06,390 --> 00:33:06,400 is complete a satellite is left in orbit 1255 00:33:06,400 --> 00:33:08,940 is complete a satellite is left in orbit or is deorbited burning up when 1256 00:33:08,940 --> 00:33:08,950 or is deorbited burning up when 1257 00:33:08,950 --> 00:33:11,870 or is deorbited burning up when re-entering the Earth's atmosphere 1258 00:33:11,870 --> 00:33:11,880 re-entering the Earth's atmosphere 1259 00:33:11,880 --> 00:33:14,340 re-entering the Earth's atmosphere when the Space Shuttle completes its 1260 00:33:14,340 --> 00:33:14,350 when the Space Shuttle completes its 1261 00:33:14,350 --> 00:33:16,800 when the Space Shuttle completes its orbital mission it executes a precise 1262 00:33:16,800 --> 00:33:16,810 orbital mission it executes a precise 1263 00:33:16,810 --> 00:33:19,650 orbital mission it executes a precise retrograde burn to initiate its 1264 00:33:19,650 --> 00:33:19,660 retrograde burn to initiate its 1265 00:33:19,660 --> 00:33:22,650 retrograde burn to initiate its controlled return to earth this burn 1266 00:33:22,650 --> 00:33:22,660 controlled return to earth this burn 1267 00:33:22,660 --> 00:33:24,990 controlled return to earth this burn occurs nearly halfway around the Earth 1268 00:33:24,990 --> 00:33:25,000 occurs nearly halfway around the Earth 1269 00:33:25,000 --> 00:33:27,440 occurs nearly halfway around the Earth from the landing site 1270 00:33:27,440 --> 00:33:27,450 from the landing site 1271 00:33:27,450 --> 00:33:29,450 from the landing site the new orbit established by the 1272 00:33:29,450 --> 00:33:29,460 the new orbit established by the 1273 00:33:29,460 --> 00:33:32,150 the new orbit established by the retrograde burn causes the orbiter to 1274 00:33:32,150 --> 00:33:32,160 retrograde burn causes the orbiter to 1275 00:33:32,160 --> 00:33:34,730 retrograde burn causes the orbiter to enter the Earth's atmosphere about four 1276 00:33:34,730 --> 00:33:34,740 enter the Earth's atmosphere about four 1277 00:33:34,740 --> 00:33:36,560 enter the Earth's atmosphere about four thousand miles from the landing site 1278 00:33:36,560 --> 00:33:36,570 thousand miles from the landing site 1279 00:33:36,570 --> 00:33:39,320 thousand miles from the landing site during the period the orbiter descends 1280 00:33:39,320 --> 00:33:39,330 during the period the orbiter descends 1281 00:33:39,330 --> 00:33:41,600 during the period the orbiter descends from its orbital altitude to atmospheric 1282 00:33:41,600 --> 00:33:41,610 from its orbital altitude to atmospheric 1283 00:33:41,610 --> 00:33:44,600 from its orbital altitude to atmospheric reentry its attitude is maintained by 1284 00:33:44,600 --> 00:33:44,610 reentry its attitude is maintained by 1285 00:33:44,610 --> 00:33:47,510 reentry its attitude is maintained by the use of reaction control jets located 1286 00:33:47,510 --> 00:33:47,520 the use of reaction control jets located 1287 00:33:47,520 --> 00:33:51,980 the use of reaction control jets located in the nose and tail of the orbiter once 1288 00:33:51,980 --> 00:33:51,990 in the nose and tail of the orbiter once 1289 00:33:51,990 --> 00:33:53,270 in the nose and tail of the orbiter once the orbiter enters the Earth's 1290 00:33:53,270 --> 00:33:53,280 the orbiter enters the Earth's 1291 00:33:53,280 --> 00:33:56,150 the orbiter enters the Earth's atmosphere its wing and tail arrow 1292 00:33:56,150 --> 00:33:56,160 atmosphere its wing and tail arrow 1293 00:33:56,160 --> 00:33:58,670 atmosphere its wing and tail arrow surfaces begin to become effective and 1294 00:33:58,670 --> 00:33:58,680 surfaces begin to become effective and 1295 00:33:58,680 --> 00:34:01,460 surfaces begin to become effective and gradually replace the Jets for attitude 1296 00:34:01,460 --> 00:34:01,470 gradually replace the Jets for attitude 1297 00:34:01,470 --> 00:34:05,480 gradually replace the Jets for attitude control as the orbiter nears the landing 1298 00:34:05,480 --> 00:34:05,490 control as the orbiter nears the landing 1299 00:34:05,490 --> 00:34:08,330 control as the orbiter nears the landing field it maneuvers to a long straight in 1300 00:34:08,330 --> 00:34:08,340 field it maneuvers to a long straight in 1301 00:34:08,340 --> 00:34:13,360 field it maneuvers to a long straight in approach at an angle of 17 to 19 degrees 1302 00:34:13,360 --> 00:34:13,370 approach at an angle of 17 to 19 degrees 1303 00:34:13,370 --> 00:34:16,430 approach at an angle of 17 to 19 degrees nearing the runway it executes a flare 1304 00:34:16,430 --> 00:34:16,440 nearing the runway it executes a flare 1305 00:34:16,440 --> 00:34:18,680 nearing the runway it executes a flare maneuver to reduce its sink rate and 1306 00:34:18,680 --> 00:34:18,690 maneuver to reduce its sink rate and 1307 00:34:18,690 --> 00:34:21,260 maneuver to reduce its sink rate and glides to a touchdown at approximately 1308 00:34:21,260 --> 00:34:21,270 glides to a touchdown at approximately 1309 00:34:21,270 --> 00:34:25,669 glides to a touchdown at approximately 230 miles per hour as the orbiter rolls 1310 00:34:25,669 --> 00:34:25,679 230 miles per hour as the orbiter rolls 1311 00:34:25,679 --> 00:34:28,610 230 miles per hour as the orbiter rolls to a stop our journey into the world of 1312 00:34:28,610 --> 00:34:28,620 to a stop our journey into the world of 1313 00:34:28,620 --> 00:34:31,220 to a stop our journey into the world of orbital mechanics comes to an end for 1314 00:34:31,220 --> 00:34:31,230 orbital mechanics comes to an end for 1315 00:34:31,230 --> 00:34:32,290 orbital mechanics comes to an end for now 1316 00:34:32,290 --> 00:34:32,300 now 1317 00:34:32,300 --> 00:34:35,000 now this is only the basics of orbital 1318 00:34:35,000 --> 00:34:35,010 this is only the basics of orbital 1319 00:34:35,010 --> 00:34:37,040 this is only the basics of orbital mechanics an intricate study of 1320 00:34:37,040 --> 00:34:37,050 mechanics an intricate study of 1321 00:34:37,050 --> 00:34:40,099 mechanics an intricate study of planetary and satellite motion the next 1322 00:34:40,099 --> 00:34:40,109 planetary and satellite motion the next 1323 00:34:40,109 --> 00:34:42,169 planetary and satellite motion the next time you see a launch you will see it 1324 00:34:42,169 --> 00:34:42,179 time you see a launch you will see it 1325 00:34:42,179 --> 00:34:44,200 time you see a launch you will see it from a different somewhat knowledgeable 1326 00:34:44,200 --> 00:34:44,210 from a different somewhat knowledgeable 1327 00:34:44,210 --> 00:34:47,569 from a different somewhat knowledgeable perspective you will understand the 1328 00:34:47,569 --> 00:34:47,579 perspective you will understand the 1329 00:34:47,579 --> 00:35:51,840 perspective you will understand the fundamentals of spaceflight 1330 00:35:51,840 --> 00:35:51,850 1331 00:35:51,850 --> 00:36:03,060 Oh 1332 00:36:03,060 --> 00:36:03,070 1333 00:36:03,070 --> 00:36:05,130 you