1 00:00:23,230 --> 00:00:27,880 9 we have a go for main engine start 2 00:00:27,880 --> 00:00:27,890 9 we have a go for main engine start 3 00:00:27,890 --> 00:00:34,030 9 we have a go for main engine start five four three two one zero booster 4 00:00:34,030 --> 00:00:34,040 five four three two one zero booster 5 00:00:34,040 --> 00:00:37,390 five four three two one zero booster ignition and liftoff of Columbia a new 6 00:00:37,390 --> 00:00:37,400 ignition and liftoff of Columbia a new 7 00:00:37,400 --> 00:01:06,100 ignition and liftoff of Columbia a new decade of spaceflight begins six five 8 00:01:06,100 --> 00:01:06,110 decade of spaceflight begins six five 9 00:01:06,110 --> 00:01:12,609 decade of spaceflight begins six five four three two one ignition and liftoff 10 00:01:12,609 --> 00:01:12,619 four three two one ignition and liftoff 11 00:01:12,619 --> 00:01:15,310 four three two one ignition and liftoff of discovery and the Ulysses spacecraft 12 00:01:15,310 --> 00:01:15,320 of discovery and the Ulysses spacecraft 13 00:01:15,320 --> 00:01:21,900 of discovery and the Ulysses spacecraft bound for the polar regions of the Sun 14 00:01:21,900 --> 00:01:21,910 15 00:01:21,910 --> 00:01:25,840 that Space Shuttle Orbiter is rocketing 16 00:01:25,840 --> 00:01:25,850 that Space Shuttle Orbiter is rocketing 17 00:01:25,850 --> 00:01:31,240 that Space Shuttle Orbiter is rocketing into space but what is space how do we 18 00:01:31,240 --> 00:01:31,250 into space but what is space how do we 19 00:01:31,250 --> 00:01:36,910 into space but what is space how do we get there how do we stay there how do we 20 00:01:36,910 --> 00:01:36,920 get there how do we stay there how do we 21 00:01:36,920 --> 00:01:40,539 get there how do we stay there how do we get back to earth again well before we 22 00:01:40,539 --> 00:01:40,549 get back to earth again well before we 23 00:01:40,549 --> 00:01:43,210 get back to earth again well before we answer these questions let's look at 24 00:01:43,210 --> 00:01:43,220 answer these questions let's look at 25 00:01:43,220 --> 00:01:46,980 answer these questions let's look at some history of man Rockets this man 26 00:01:46,980 --> 00:01:46,990 some history of man Rockets this man 27 00:01:46,990 --> 00:01:50,469 some history of man Rockets this man Robert H Goddard is considered to be the 28 00:01:50,469 --> 00:01:50,479 Robert H Goddard is considered to be the 29 00:01:50,479 --> 00:01:53,620 Robert H Goddard is considered to be the father of modern rocketry he began 30 00:01:53,620 --> 00:01:53,630 father of modern rocketry he began 31 00:01:53,630 --> 00:01:57,270 father of modern rocketry he began testing Rockets as a young man and in 32 00:01:57,270 --> 00:01:57,280 testing Rockets as a young man and in 33 00:01:57,280 --> 00:02:00,459 testing Rockets as a young man and in 1926 he launched the world's first 34 00:02:00,459 --> 00:02:00,469 1926 he launched the world's first 35 00:02:00,469 --> 00:02:04,300 1926 he launched the world's first liquid-fuel rocket he was also the first 36 00:02:04,300 --> 00:02:04,310 liquid-fuel rocket he was also the first 37 00:02:04,310 --> 00:02:06,700 liquid-fuel rocket he was also the first to propose using both solid and liquid 38 00:02:06,700 --> 00:02:06,710 to propose using both solid and liquid 39 00:02:06,710 --> 00:02:11,949 to propose using both solid and liquid propellants on the same rocket 40 00:02:11,949 --> 00:02:11,959 41 00:02:11,959 --> 00:02:15,250 why is that an important idea because 42 00:02:15,250 --> 00:02:15,260 why is that an important idea because 43 00:02:15,260 --> 00:02:16,869 why is that an important idea because that's how he boosts the Space Shuttle 44 00:02:16,869 --> 00:02:16,879 that's how he boosts the Space Shuttle 45 00:02:16,879 --> 00:02:23,259 that's how he boosts the Space Shuttle into orbit today it was in 1956 when a 46 00:02:23,259 --> 00:02:23,269 into orbit today it was in 1956 when a 47 00:02:23,269 --> 00:02:25,960 into orbit today it was in 1956 when a team of scientists engineers led by 48 00:02:25,960 --> 00:02:25,970 team of scientists engineers led by 49 00:02:25,970 --> 00:02:28,599 team of scientists engineers led by Bernhard von Braun launched the Jupiter 50 00:02:28,599 --> 00:02:28,609 Bernhard von Braun launched the Jupiter 51 00:02:28,609 --> 00:02:33,069 Bernhard von Braun launched the Jupiter C rocket this was the first time that we 52 00:02:33,069 --> 00:02:33,079 C rocket this was the first time that we 53 00:02:33,079 --> 00:02:35,110 C rocket this was the first time that we launched anything that went high enough 54 00:02:35,110 --> 00:02:35,120 launched anything that went high enough 55 00:02:35,120 --> 00:02:39,520 launched anything that went high enough to get into space two years later 56 00:02:39,520 --> 00:02:39,530 to get into space two years later 57 00:02:39,530 --> 00:02:43,240 to get into space two years later another Jupiter C traveled in space but 58 00:02:43,240 --> 00:02:43,250 another Jupiter C traveled in space but 59 00:02:43,250 --> 00:02:45,369 another Jupiter C traveled in space but this time had left a satellite up there 60 00:02:45,369 --> 00:02:45,379 this time had left a satellite up there 61 00:02:45,379 --> 00:02:50,140 this time had left a satellite up there to orbit the earth then in 1961 only 62 00:02:50,140 --> 00:02:50,150 to orbit the earth then in 1961 only 63 00:02:50,150 --> 00:02:52,119 to orbit the earth then in 1961 only months after the Soviet Union sent their 64 00:02:52,119 --> 00:02:52,129 months after the Soviet Union sent their 65 00:02:52,129 --> 00:02:55,330 months after the Soviet Union sent their first astronaut into space NASA launched 66 00:02:55,330 --> 00:02:55,340 first astronaut into space NASA launched 67 00:02:55,340 --> 00:02:57,339 first astronaut into space NASA launched the first American into space on board 68 00:02:57,339 --> 00:02:57,349 the first American into space on board 69 00:02:57,349 --> 00:03:01,599 the first American into space on board the Freedom say things were moving 70 00:03:01,599 --> 00:03:01,609 the Freedom say things were moving 71 00:03:01,609 --> 00:03:05,860 the Freedom say things were moving pretty fast first we had the mercury 72 00:03:05,860 --> 00:03:05,870 pretty fast first we had the mercury 73 00:03:05,870 --> 00:03:08,250 pretty fast first we had the mercury program 74 00:03:08,250 --> 00:03:08,260 75 00:03:08,260 --> 00:03:15,119 then Gemini and then just eight years 76 00:03:15,119 --> 00:03:15,129 then Gemini and then just eight years 77 00:03:15,129 --> 00:03:17,100 then Gemini and then just eight years after the first human would went into 78 00:03:17,100 --> 00:03:17,110 after the first human would went into 79 00:03:17,110 --> 00:03:20,580 after the first human would went into space a Saturn 5 rocket launched the 80 00:03:20,580 --> 00:03:20,590 space a Saturn 5 rocket launched the 81 00:03:20,590 --> 00:03:26,100 space a Saturn 5 rocket launched the Apollo spacecraft carrying the first 82 00:03:26,100 --> 00:03:26,110 Apollo spacecraft carrying the first 83 00:03:26,110 --> 00:03:29,990 Apollo spacecraft carrying the first astronauts to the moon 84 00:03:29,990 --> 00:03:30,000 85 00:03:30,000 --> 00:03:32,940 today astronauts fly into space in a 86 00:03:32,940 --> 00:03:32,950 today astronauts fly into space in a 87 00:03:32,950 --> 00:03:39,720 today astronauts fly into space in a different vehicle the Space Shuttle 88 00:03:39,720 --> 00:03:39,730 different vehicle the Space Shuttle 89 00:03:39,730 --> 00:03:44,369 different vehicle the Space Shuttle Orbiter to give us enough energy to get 90 00:03:44,369 --> 00:03:44,379 Orbiter to give us enough energy to get 91 00:03:44,379 --> 00:03:46,949 Orbiter to give us enough energy to get into orbit we use special engines and 92 00:03:46,949 --> 00:03:46,959 into orbit we use special engines and 93 00:03:46,959 --> 00:03:50,099 into orbit we use special engines and propellants let's look at the shuttle a 94 00:03:50,099 --> 00:03:50,109 propellants let's look at the shuttle a 95 00:03:50,109 --> 00:03:57,119 propellants let's look at the shuttle a little differently this is what we call 96 00:03:57,119 --> 00:03:57,129 little differently this is what we call 97 00:03:57,129 --> 00:04:00,030 little differently this is what we call the stack sitting on the launch pad here 98 00:04:00,030 --> 00:04:00,040 the stack sitting on the launch pad here 99 00:04:00,040 --> 00:04:03,089 the stack sitting on the launch pad here in Florida let's look at it the way an 100 00:04:03,089 --> 00:04:03,099 in Florida let's look at it the way an 101 00:04:03,099 --> 00:04:10,589 in Florida let's look at it the way an engineer might look at it 102 00:04:10,589 --> 00:04:10,599 103 00:04:10,599 --> 00:04:14,429 the solid rocket boosters or SRBs burn a 104 00:04:14,429 --> 00:04:14,439 the solid rocket boosters or SRBs burn a 105 00:04:14,439 --> 00:04:18,659 the solid rocket boosters or SRBs burn a solid fuel the external tank where ET 106 00:04:18,659 --> 00:04:18,669 solid fuel the external tank where ET 107 00:04:18,669 --> 00:04:20,580 solid fuel the external tank where ET carries liquid oxygen and liquid 108 00:04:20,580 --> 00:04:20,590 carries liquid oxygen and liquid 109 00:04:20,590 --> 00:04:23,570 carries liquid oxygen and liquid hydrogen for the shuttles main engines 110 00:04:23,570 --> 00:04:23,580 hydrogen for the shuttles main engines 111 00:04:23,580 --> 00:04:26,400 hydrogen for the shuttles main engines this combination of solid and liquid 112 00:04:26,400 --> 00:04:26,410 this combination of solid and liquid 113 00:04:26,410 --> 00:04:30,689 this combination of solid and liquid propellants are very powerful we're 114 00:04:30,689 --> 00:04:30,699 propellants are very powerful we're 115 00:04:30,699 --> 00:04:32,700 propellants are very powerful we're launch we start the liquid main engines 116 00:04:32,700 --> 00:04:32,710 launch we start the liquid main engines 117 00:04:32,710 --> 00:04:37,650 launch we start the liquid main engines burst then the solid rocket boosters 118 00:04:37,650 --> 00:04:37,660 burst then the solid rocket boosters 119 00:04:37,660 --> 00:04:40,020 burst then the solid rocket boosters ignite and lift the whole stack off the 120 00:04:40,020 --> 00:04:40,030 ignite and lift the whole stack off the 121 00:04:40,030 --> 00:04:45,420 ignite and lift the whole stack off the pad downrange twenty two nautical miles 122 00:04:45,420 --> 00:04:45,430 pad downrange twenty two nautical miles 123 00:04:45,430 --> 00:04:47,460 pad downrange twenty two nautical miles the solid rocket boosters push the 124 00:04:47,460 --> 00:04:47,470 the solid rocket boosters push the 125 00:04:47,470 --> 00:04:49,439 the solid rocket boosters push the shuttle for about two minutes and up 126 00:04:49,439 --> 00:04:49,449 shuttle for about two minutes and up 127 00:04:49,449 --> 00:04:50,700 shuttle for about two minutes and up through the thickest part of the 128 00:04:50,700 --> 00:04:50,710 through the thickest part of the 129 00:04:50,710 --> 00:04:53,430 through the thickest part of the atmosphere then we separate from the 130 00:04:53,430 --> 00:04:53,440 atmosphere then we separate from the 131 00:04:53,440 --> 00:04:59,100 atmosphere then we separate from the Boosters the shuttles main engines 132 00:04:59,100 --> 00:04:59,110 Boosters the shuttles main engines 133 00:04:59,110 --> 00:05:01,770 Boosters the shuttles main engines continue to burn for another seven 134 00:05:01,770 --> 00:05:01,780 continue to burn for another seven 135 00:05:01,780 --> 00:05:02,159 continue to burn for another seven minutes 136 00:05:02,159 --> 00:05:02,169 minutes 137 00:05:02,169 --> 00:05:04,800 minutes pushing the orbiter fast enough to get 138 00:05:04,800 --> 00:05:04,810 pushing the orbiter fast enough to get 139 00:05:04,810 --> 00:05:24,150 pushing the orbiter fast enough to get into space okay 140 00:05:24,150 --> 00:05:24,160 141 00:05:24,160 --> 00:05:28,180 and here's the result we're in space but 142 00:05:28,180 --> 00:05:28,190 and here's the result we're in space but 143 00:05:28,190 --> 00:05:30,310 and here's the result we're in space but we're in space are we in other words how 144 00:05:30,310 --> 00:05:30,320 we're in space are we in other words how 145 00:05:30,320 --> 00:05:33,070 we're in space are we in other words how far above the earth have we come let's 146 00:05:33,070 --> 00:05:33,080 far above the earth have we come let's 147 00:05:33,080 --> 00:05:37,480 far above the earth have we come let's use this picture to help explain here is 148 00:05:37,480 --> 00:05:37,490 use this picture to help explain here is 149 00:05:37,490 --> 00:05:41,920 use this picture to help explain here is the surface of the earth here would be 150 00:05:41,920 --> 00:05:41,930 the surface of the earth here would be 151 00:05:41,930 --> 00:05:43,600 the surface of the earth here would be the Earth's highest mountain Mount 152 00:05:43,600 --> 00:05:43,610 the Earth's highest mountain Mount 153 00:05:43,610 --> 00:05:46,000 the Earth's highest mountain Mount Everest which is about 6 miles high and 154 00:05:46,000 --> 00:05:46,010 Everest which is about 6 miles high and 155 00:05:46,010 --> 00:05:49,210 Everest which is about 6 miles high and right here would be where commercial 156 00:05:49,210 --> 00:05:49,220 right here would be where commercial 157 00:05:49,220 --> 00:05:52,330 right here would be where commercial airplanes fly about 6 to 7 miles above 158 00:05:52,330 --> 00:05:52,340 airplanes fly about 6 to 7 miles above 159 00:05:52,340 --> 00:05:55,720 airplanes fly about 6 to 7 miles above sea level the astronauts that went to 160 00:05:55,720 --> 00:05:55,730 sea level the astronauts that went to 161 00:05:55,730 --> 00:05:58,870 sea level the astronauts that went to the moon went 240 thousand miles above 162 00:05:58,870 --> 00:05:58,880 the moon went 240 thousand miles above 163 00:05:58,880 --> 00:06:00,970 the moon went 240 thousand miles above the earth and if we can put that on this 164 00:06:00,970 --> 00:06:00,980 the earth and if we can put that on this 165 00:06:00,980 --> 00:06:04,060 the earth and if we can put that on this picture to scale it would be 5000 feet 166 00:06:04,060 --> 00:06:04,070 picture to scale it would be 5000 feet 167 00:06:04,070 --> 00:06:07,270 picture to scale it would be 5000 feet this way well where does that leave us 168 00:06:07,270 --> 00:06:07,280 this way well where does that leave us 169 00:06:07,280 --> 00:06:09,640 this way well where does that leave us here in the Space Shuttle well right now 170 00:06:09,640 --> 00:06:09,650 here in the Space Shuttle well right now 171 00:06:09,650 --> 00:06:12,640 here in the Space Shuttle well right now in the Space Shuttle we are about right 172 00:06:12,640 --> 00:06:12,650 in the Space Shuttle we are about right 173 00:06:12,650 --> 00:06:17,110 in the Space Shuttle we are about right here 160 miles above the earth for 174 00:06:17,110 --> 00:06:17,120 here 160 miles above the earth for 175 00:06:17,120 --> 00:06:18,820 here 160 miles above the earth for example though the Space Shuttle can 176 00:06:18,820 --> 00:06:18,830 example though the Space Shuttle can 177 00:06:18,830 --> 00:06:21,940 example though the Space Shuttle can even go higher sts-31 that deployed the 178 00:06:21,940 --> 00:06:21,950 even go higher sts-31 that deployed the 179 00:06:21,950 --> 00:06:24,190 even go higher sts-31 that deployed the Hubble Space Telescope went all the way 180 00:06:24,190 --> 00:06:24,200 Hubble Space Telescope went all the way 181 00:06:24,200 --> 00:06:31,140 Hubble Space Telescope went all the way out to here 300 miles above the earth 182 00:06:31,140 --> 00:06:31,150 183 00:06:31,150 --> 00:06:33,720 so what's it like up here well let's do 184 00:06:33,720 --> 00:06:33,730 so what's it like up here well let's do 185 00:06:33,730 --> 00:06:38,580 so what's it like up here well let's do a weather report from space well Tom I'm 186 00:06:38,580 --> 00:06:38,590 a weather report from space well Tom I'm 187 00:06:38,590 --> 00:06:39,750 a weather report from space well Tom I'm gonna have a little problem with that 188 00:06:39,750 --> 00:06:39,760 gonna have a little problem with that 189 00:06:39,760 --> 00:06:42,930 gonna have a little problem with that because there is no weather in space in 190 00:06:42,930 --> 00:06:42,940 because there is no weather in space in 191 00:06:42,940 --> 00:06:44,400 because there is no weather in space in order to have whether you have to have 192 00:06:44,400 --> 00:06:44,410 order to have whether you have to have 193 00:06:44,410 --> 00:06:46,620 order to have whether you have to have an atmosphere up here in the Space 194 00:06:46,620 --> 00:06:46,630 an atmosphere up here in the Space 195 00:06:46,630 --> 00:06:47,969 an atmosphere up here in the Space Shuttle we're well above the Earth's 196 00:06:47,969 --> 00:06:47,979 Shuttle we're well above the Earth's 197 00:06:47,979 --> 00:06:50,670 Shuttle we're well above the Earth's atmosphere so I can't give you a port on 198 00:06:50,670 --> 00:06:50,680 atmosphere so I can't give you a port on 199 00:06:50,680 --> 00:06:52,710 atmosphere so I can't give you a port on their weather but I can tell you what 200 00:06:52,710 --> 00:06:52,720 their weather but I can tell you what 201 00:06:52,720 --> 00:06:53,760 their weather but I can tell you what the conditions are going to be like 202 00:06:53,760 --> 00:06:53,770 the conditions are going to be like 203 00:06:53,770 --> 00:06:57,570 the conditions are going to be like outside today we can expect a scorching 204 00:06:57,570 --> 00:06:57,580 outside today we can expect a scorching 205 00:06:57,580 --> 00:06:59,250 outside today we can expect a scorching high of about 300 degrees Fahrenheit 206 00:06:59,250 --> 00:06:59,260 high of about 300 degrees Fahrenheit 207 00:06:59,260 --> 00:07:02,159 high of about 300 degrees Fahrenheit outside today in the Sun that's about 208 00:07:02,159 --> 00:07:02,169 outside today in the Sun that's about 209 00:07:02,169 --> 00:07:05,520 outside today in the Sun that's about 150 degrees celcius down to a real 210 00:07:05,520 --> 00:07:05,530 150 degrees celcius down to a real 211 00:07:05,530 --> 00:07:08,210 150 degrees celcius down to a real freezing low of 150 degrees below zero 212 00:07:08,210 --> 00:07:08,220 freezing low of 150 degrees below zero 213 00:07:08,220 --> 00:07:10,950 freezing low of 150 degrees below zero which is a minus 100 degrees Celsius in 214 00:07:10,950 --> 00:07:10,960 which is a minus 100 degrees Celsius in 215 00:07:10,960 --> 00:07:13,260 which is a minus 100 degrees Celsius in the shade we can expect the relative 216 00:07:13,260 --> 00:07:13,270 the shade we can expect the relative 217 00:07:13,270 --> 00:07:15,510 the shade we can expect the relative humidity to be zero and our barometric 218 00:07:15,510 --> 00:07:15,520 humidity to be zero and our barometric 219 00:07:15,520 --> 00:07:17,969 humidity to be zero and our barometric pressure is also going to be zero now 220 00:07:17,969 --> 00:07:17,979 pressure is also going to be zero now 221 00:07:17,979 --> 00:07:19,260 pressure is also going to be zero now some of our viewers out there may be 222 00:07:19,260 --> 00:07:19,270 some of our viewers out there may be 223 00:07:19,270 --> 00:07:21,540 some of our viewers out there may be wondering why are these extreme 224 00:07:21,540 --> 00:07:21,550 wondering why are these extreme 225 00:07:21,550 --> 00:07:23,340 wondering why are these extreme conditions outside when we're only a 226 00:07:23,340 --> 00:07:23,350 conditions outside when we're only a 227 00:07:23,350 --> 00:07:25,140 conditions outside when we're only a hundred and sixty miles up above the 228 00:07:25,140 --> 00:07:25,150 hundred and sixty miles up above the 229 00:07:25,150 --> 00:07:26,520 hundred and sixty miles up above the Earth's surface and the living 230 00:07:26,520 --> 00:07:26,530 Earth's surface and the living 231 00:07:26,530 --> 00:07:28,800 Earth's surface and the living conditions down there are so nice well 232 00:07:28,800 --> 00:07:28,810 conditions down there are so nice well 233 00:07:28,810 --> 00:07:30,480 conditions down there are so nice well the reason is is down on the surface of 234 00:07:30,480 --> 00:07:30,490 the reason is is down on the surface of 235 00:07:30,490 --> 00:07:33,090 the reason is is down on the surface of the earth we have an atmosphere the 236 00:07:33,090 --> 00:07:33,100 the earth we have an atmosphere the 237 00:07:33,100 --> 00:07:35,820 the earth we have an atmosphere the atmosphere performed as a protective 238 00:07:35,820 --> 00:07:35,830 atmosphere performed as a protective 239 00:07:35,830 --> 00:07:38,159 atmosphere performed as a protective blanket for us when we live down on the 240 00:07:38,159 --> 00:07:38,169 blanket for us when we live down on the 241 00:07:38,169 --> 00:07:42,000 blanket for us when we live down on the surface of the earth here for example is 242 00:07:42,000 --> 00:07:42,010 surface of the earth here for example is 243 00:07:42,010 --> 00:07:43,379 surface of the earth here for example is a picture of what the earth looks like 244 00:07:43,379 --> 00:07:43,389 a picture of what the earth looks like 245 00:07:43,389 --> 00:07:45,750 a picture of what the earth looks like from a satellite 23,000 miles above the 246 00:07:45,750 --> 00:07:45,760 from a satellite 23,000 miles above the 247 00:07:45,760 --> 00:07:47,610 from a satellite 23,000 miles above the earth you can see that much of the 248 00:07:47,610 --> 00:07:47,620 earth you can see that much of the 249 00:07:47,620 --> 00:07:48,870 earth you can see that much of the surface of the earth is covered by 250 00:07:48,870 --> 00:07:48,880 surface of the earth is covered by 251 00:07:48,880 --> 00:07:51,570 surface of the earth is covered by clouds these clouds are the part of the 252 00:07:51,570 --> 00:07:51,580 clouds these clouds are the part of the 253 00:07:51,580 --> 00:07:53,279 clouds these clouds are the part of the atmosphere that you can see the visible 254 00:07:53,279 --> 00:07:53,289 atmosphere that you can see the visible 255 00:07:53,289 --> 00:07:55,350 atmosphere that you can see the visible part of the atmosphere the clouds were 256 00:07:55,350 --> 00:07:55,360 part of the atmosphere the clouds were 257 00:07:55,360 --> 00:07:57,450 part of the atmosphere the clouds were made up of water molecules those water 258 00:07:57,450 --> 00:07:57,460 made up of water molecules those water 259 00:07:57,460 --> 00:07:59,279 made up of water molecules those water molecules are what account for the 260 00:07:59,279 --> 00:07:59,289 molecules are what account for the 261 00:07:59,289 --> 00:08:01,230 molecules are what account for the relative humidity of our atmosphere the 262 00:08:01,230 --> 00:08:01,240 relative humidity of our atmosphere the 263 00:08:01,240 --> 00:08:03,420 relative humidity of our atmosphere the total weight of the atmosphere above a 264 00:08:03,420 --> 00:08:03,430 total weight of the atmosphere above a 265 00:08:03,430 --> 00:08:05,430 total weight of the atmosphere above a point on the surface of the earth is 266 00:08:05,430 --> 00:08:05,440 point on the surface of the earth is 267 00:08:05,440 --> 00:08:07,529 point on the surface of the earth is what it makes up for the barometric 268 00:08:07,529 --> 00:08:07,539 what it makes up for the barometric 269 00:08:07,539 --> 00:08:10,230 what it makes up for the barometric pressure now we don't have to worry 270 00:08:10,230 --> 00:08:10,240 pressure now we don't have to worry 271 00:08:10,240 --> 00:08:11,640 pressure now we don't have to worry about our climate here in the Space 272 00:08:11,640 --> 00:08:11,650 about our climate here in the Space 273 00:08:11,650 --> 00:08:12,750 about our climate here in the Space Shuttle when we're up here in space 274 00:08:12,750 --> 00:08:12,760 Shuttle when we're up here in space 275 00:08:12,760 --> 00:08:15,210 Shuttle when we're up here in space because we have an air-conditioner but 276 00:08:15,210 --> 00:08:15,220 because we have an air-conditioner but 277 00:08:15,220 --> 00:08:17,190 because we have an air-conditioner but we call our environmental control system 278 00:08:17,190 --> 00:08:17,200 we call our environmental control system 279 00:08:17,200 --> 00:08:19,650 we call our environmental control system on board this environmental control 280 00:08:19,650 --> 00:08:19,660 on board this environmental control 281 00:08:19,660 --> 00:08:22,110 on board this environmental control system will maintain our temperature a 282 00:08:22,110 --> 00:08:22,120 system will maintain our temperature a 283 00:08:22,120 --> 00:08:24,900 system will maintain our temperature a nice comfortable 77 degrees Fahrenheit 284 00:08:24,900 --> 00:08:24,910 nice comfortable 77 degrees Fahrenheit 285 00:08:24,910 --> 00:08:27,260 nice comfortable 77 degrees Fahrenheit which is about 25 degrees Celsius 286 00:08:27,260 --> 00:08:27,270 which is about 25 degrees Celsius 287 00:08:27,270 --> 00:08:29,460 which is about 25 degrees Celsius relative humidity will stay at about a 288 00:08:29,460 --> 00:08:29,470 relative humidity will stay at about a 289 00:08:29,470 --> 00:08:32,070 relative humidity will stay at about a constant 50% enter barometric pressure 290 00:08:32,070 --> 00:08:32,080 constant 50% enter barometric pressure 291 00:08:32,080 --> 00:08:34,370 constant 50% enter barometric pressure will be about 29.92 inches of mercury 292 00:08:34,370 --> 00:08:34,380 will be about 29.92 inches of mercury 293 00:08:34,380 --> 00:08:37,220 will be about 29.92 inches of mercury back to you Tom 294 00:08:37,220 --> 00:08:37,230 back to you Tom 295 00:08:37,230 --> 00:08:43,100 back to you Tom thanks Bruce as you can see the 296 00:08:43,100 --> 00:08:43,110 thanks Bruce as you can see the 297 00:08:43,110 --> 00:08:45,800 thanks Bruce as you can see the environment in space is very harsh so 298 00:08:45,800 --> 00:08:45,810 environment in space is very harsh so 299 00:08:45,810 --> 00:08:47,900 environment in space is very harsh so here in the orbiter we have to make the 300 00:08:47,900 --> 00:08:47,910 here in the orbiter we have to make the 301 00:08:47,910 --> 00:08:49,880 here in the orbiter we have to make the environment duplicate the environment 302 00:08:49,880 --> 00:08:49,890 environment duplicate the environment 303 00:08:49,890 --> 00:09:02,110 environment duplicate the environment that is down on the Earth's surface 304 00:09:02,110 --> 00:09:02,120 305 00:09:02,120 --> 00:09:04,840 and even though we're over 150 miles up 306 00:09:04,840 --> 00:09:04,850 and even though we're over 150 miles up 307 00:09:04,850 --> 00:09:07,360 and even though we're over 150 miles up in space here the pressure inside the 308 00:09:07,360 --> 00:09:07,370 in space here the pressure inside the 309 00:09:07,370 --> 00:09:09,819 in space here the pressure inside the space shuttle is almost the same as it 310 00:09:09,819 --> 00:09:09,829 space shuttle is almost the same as it 311 00:09:09,829 --> 00:09:11,799 space shuttle is almost the same as it is at sea level see it's fool this 312 00:09:11,799 --> 00:09:11,809 is at sea level see it's fool this 313 00:09:11,809 --> 00:09:16,119 is at sea level see it's fool this altimeter into reading almost zero well 314 00:09:16,119 --> 00:09:16,129 altimeter into reading almost zero well 315 00:09:16,129 --> 00:09:19,420 altimeter into reading almost zero well now we know where space is and what 316 00:09:19,420 --> 00:09:19,430 now we know where space is and what 317 00:09:19,430 --> 00:09:23,110 now we know where space is and what space is how do we stay here 318 00:09:23,110 --> 00:09:23,120 space is how do we stay here 319 00:09:23,120 --> 00:09:28,960 space is how do we stay here once we've arrived well 300 years ago an 320 00:09:28,960 --> 00:09:28,970 once we've arrived well 300 years ago an 321 00:09:28,970 --> 00:09:32,850 once we've arrived well 300 years ago an English scientist Sir Isaac Newton 322 00:09:32,850 --> 00:09:32,860 English scientist Sir Isaac Newton 323 00:09:32,860 --> 00:09:46,850 English scientist Sir Isaac Newton figured out a way to do this 324 00:09:46,850 --> 00:09:46,860 325 00:09:46,860 --> 00:09:51,610 he began by showing a very high mountain 326 00:09:51,610 --> 00:09:51,620 327 00:09:51,620 --> 00:09:54,770 the imaginary mountain was so high that 328 00:09:54,770 --> 00:09:54,780 the imaginary mountain was so high that 329 00:09:54,780 --> 00:10:00,280 the imaginary mountain was so high that its peak poked above all the atmosphere 330 00:10:00,280 --> 00:10:00,290 331 00:10:00,290 --> 00:10:03,320 he put a cannon on top of the mountain 332 00:10:03,320 --> 00:10:03,330 he put a cannon on top of the mountain 333 00:10:03,330 --> 00:10:14,519 he put a cannon on top of the mountain and fired cannonballs will use baseballs 334 00:10:14,519 --> 00:10:14,529 335 00:10:14,529 --> 00:10:18,730 okay here's our imaginary mountain let's 336 00:10:18,730 --> 00:10:18,740 okay here's our imaginary mountain let's 337 00:10:18,740 --> 00:10:20,740 okay here's our imaginary mountain let's pretend that we can climb to the top of 338 00:10:20,740 --> 00:10:20,750 pretend that we can climb to the top of 339 00:10:20,750 --> 00:10:26,460 pretend that we can climb to the top of this mountain with a sack of baseballs 340 00:10:26,460 --> 00:10:26,470 341 00:10:26,470 --> 00:10:29,170 now if we throw one of these baseballs 342 00:10:29,170 --> 00:10:29,180 now if we throw one of these baseballs 343 00:10:29,180 --> 00:10:30,699 now if we throw one of these baseballs straight out from the top of the 344 00:10:30,699 --> 00:10:30,709 straight out from the top of the 345 00:10:30,709 --> 00:10:33,310 straight out from the top of the mountain when it goes straight out like 346 00:10:33,310 --> 00:10:33,320 mountain when it goes straight out like 347 00:10:33,320 --> 00:10:38,980 mountain when it goes straight out like a ball straight down like B or fall on a 348 00:10:38,980 --> 00:10:38,990 a ball straight down like B or fall on a 349 00:10:38,990 --> 00:10:46,150 a ball straight down like B or fall on a curved path while C is correct the 350 00:10:46,150 --> 00:10:46,160 curved path while C is correct the 351 00:10:46,160 --> 00:10:48,210 curved path while C is correct the baseball would fall on a curved path 352 00:10:48,210 --> 00:10:48,220 baseball would fall on a curved path 353 00:10:48,220 --> 00:10:51,100 baseball would fall on a curved path even on this tall mountain it still 354 00:10:51,100 --> 00:10:51,110 even on this tall mountain it still 355 00:10:51,110 --> 00:10:54,280 even on this tall mountain it still feels gravity this is because the ball 356 00:10:54,280 --> 00:10:54,290 feels gravity this is because the ball 357 00:10:54,290 --> 00:10:56,920 feels gravity this is because the ball has two motions acting on it at the same 358 00:10:56,920 --> 00:10:56,930 has two motions acting on it at the same 359 00:10:56,930 --> 00:10:59,680 has two motions acting on it at the same time it's trying to go straight out and 360 00:10:59,680 --> 00:10:59,690 time it's trying to go straight out and 361 00:10:59,690 --> 00:11:04,329 time it's trying to go straight out and it's also falling toward the earth the 362 00:11:04,329 --> 00:11:04,339 it's also falling toward the earth the 363 00:11:04,339 --> 00:11:06,519 it's also falling toward the earth the result is the baseball travels on a 364 00:11:06,519 --> 00:11:06,529 result is the baseball travels on a 365 00:11:06,529 --> 00:11:11,910 result is the baseball travels on a curved path and lands right here 366 00:11:11,910 --> 00:11:11,920 367 00:11:11,920 --> 00:11:15,119 now let's throw another ball only this 368 00:11:15,119 --> 00:11:15,129 now let's throw another ball only this 369 00:11:15,129 --> 00:11:22,730 now let's throw another ball only this time much faster 370 00:11:22,730 --> 00:11:22,740 371 00:11:22,740 --> 00:11:27,800 see it goes farther than the first if we 372 00:11:27,800 --> 00:11:27,810 see it goes farther than the first if we 373 00:11:27,810 --> 00:11:29,750 see it goes farther than the first if we throw another ball even faster than the 374 00:11:29,750 --> 00:11:29,760 throw another ball even faster than the 375 00:11:29,760 --> 00:11:35,960 throw another ball even faster than the last one that goes farther still so the 376 00:11:35,960 --> 00:11:35,970 last one that goes farther still so the 377 00:11:35,970 --> 00:11:39,380 last one that goes farther still so the faster we throw the balls the farther 378 00:11:39,380 --> 00:11:39,390 faster we throw the balls the farther 379 00:11:39,390 --> 00:11:43,110 faster we throw the balls the farther around the earth they go 380 00:11:43,110 --> 00:11:43,120 381 00:11:43,120 --> 00:11:45,449 now we'll take our last ball and throw 382 00:11:45,449 --> 00:11:45,459 now we'll take our last ball and throw 383 00:11:45,459 --> 00:11:50,160 now we'll take our last ball and throw it as hard as we can just like the other 384 00:11:50,160 --> 00:11:50,170 it as hard as we can just like the other 385 00:11:50,170 --> 00:11:54,269 it as hard as we can just like the other balls it falls in a curved path but this 386 00:11:54,269 --> 00:11:54,279 balls it falls in a curved path but this 387 00:11:54,279 --> 00:11:56,970 balls it falls in a curved path but this one is moving so fast that it circles 388 00:11:56,970 --> 00:11:56,980 one is moving so fast that it circles 389 00:11:56,980 --> 00:12:02,840 one is moving so fast that it circles the earth we'll have to duck to missile 390 00:12:02,840 --> 00:12:02,850 the earth we'll have to duck to missile 391 00:12:02,850 --> 00:12:05,730 the earth we'll have to duck to missile it won't be safe to stand up for a while 392 00:12:05,730 --> 00:12:05,740 it won't be safe to stand up for a while 393 00:12:05,740 --> 00:12:08,400 it won't be safe to stand up for a while because unless something gets in the way 394 00:12:08,400 --> 00:12:08,410 because unless something gets in the way 395 00:12:08,410 --> 00:12:11,069 because unless something gets in the way the ball will continue to fall around 396 00:12:11,069 --> 00:12:11,079 the ball will continue to fall around 397 00:12:11,079 --> 00:12:15,480 the ball will continue to fall around the earth on a curved path we call this 398 00:12:15,480 --> 00:12:15,490 the earth on a curved path we call this 399 00:12:15,490 --> 00:12:19,290 the earth on a curved path we call this an orbit of course the Space Shuttle 400 00:12:19,290 --> 00:12:19,300 an orbit of course the Space Shuttle 401 00:12:19,300 --> 00:12:21,660 an orbit of course the Space Shuttle doesn't launch when the mountain but we 402 00:12:21,660 --> 00:12:21,670 doesn't launch when the mountain but we 403 00:12:21,670 --> 00:12:23,759 doesn't launch when the mountain but we still need a lot of speed to get into an 404 00:12:23,759 --> 00:12:23,769 still need a lot of speed to get into an 405 00:12:23,769 --> 00:12:35,400 still need a lot of speed to get into an orbit around the Earth 406 00:12:35,400 --> 00:12:35,410 407 00:12:35,410 --> 00:12:38,099 so how fast do we need to be going to 408 00:12:38,099 --> 00:12:38,109 so how fast do we need to be going to 409 00:12:38,109 --> 00:12:41,069 so how fast do we need to be going to get into orbit well it's a space shuttle 410 00:12:41,069 --> 00:12:41,079 get into orbit well it's a space shuttle 411 00:12:41,079 --> 00:12:42,869 get into orbit well it's a space shuttle at a speedometer like the one in your 412 00:12:42,869 --> 00:12:42,879 at a speedometer like the one in your 413 00:12:42,879 --> 00:12:45,379 at a speedometer like the one in your car it would have to get all the way to 414 00:12:45,379 --> 00:12:45,389 car it would have to get all the way to 415 00:12:45,389 --> 00:12:48,150 car it would have to get all the way to 17,500 miles per hour to make it into 416 00:12:48,150 --> 00:12:48,160 17,500 miles per hour to make it into 417 00:12:48,160 --> 00:12:49,609 17,500 miles per hour to make it into space 418 00:12:49,609 --> 00:12:49,619 space 419 00:12:49,619 --> 00:12:53,939 space so how fast is that well it took the 420 00:12:53,939 --> 00:12:53,949 so how fast is that well it took the 421 00:12:53,949 --> 00:12:55,769 so how fast is that well it took the early pioneers months to cross the 422 00:12:55,769 --> 00:12:55,779 early pioneers months to cross the 423 00:12:55,779 --> 00:13:12,300 early pioneers months to cross the United States by wagon 424 00:13:12,300 --> 00:13:12,310 425 00:13:12,310 --> 00:13:14,290 it took the first transcontinental 426 00:13:14,290 --> 00:13:14,300 it took the first transcontinental 427 00:13:14,300 --> 00:13:27,390 it took the first transcontinental trains a week to cross by rail 428 00:13:27,390 --> 00:13:27,400 429 00:13:27,400 --> 00:13:29,860 it would take about three days of 430 00:13:29,860 --> 00:13:29,870 it would take about three days of 431 00:13:29,870 --> 00:13:32,260 it would take about three days of driving round the clock to get across by 432 00:13:32,260 --> 00:13:32,270 driving round the clock to get across by 433 00:13:32,270 --> 00:13:39,130 driving round the clock to get across by car and it takes about five hours for 434 00:13:39,130 --> 00:13:39,140 car and it takes about five hours for 435 00:13:39,140 --> 00:13:40,450 car and it takes about five hours for the average airline that's like 436 00:13:40,450 --> 00:13:40,460 the average airline that's like 437 00:13:40,460 --> 00:13:43,210 the average airline that's like coast-to-coast but on board the shuttle 438 00:13:43,210 --> 00:13:43,220 coast-to-coast but on board the shuttle 439 00:13:43,220 --> 00:13:45,460 coast-to-coast but on board the shuttle we cross the country in ten minutes 440 00:13:45,460 --> 00:13:45,470 we cross the country in ten minutes 441 00:13:45,470 --> 00:13:49,720 we cross the country in ten minutes that's about five miles a second you see 442 00:13:49,720 --> 00:13:49,730 that's about five miles a second you see 443 00:13:49,730 --> 00:13:51,420 that's about five miles a second you see the Space Shuttle goes around the earth 444 00:13:51,420 --> 00:13:51,430 the Space Shuttle goes around the earth 445 00:13:51,430 --> 00:13:55,330 the Space Shuttle goes around the earth 16 times every earth day that means we 446 00:13:55,330 --> 00:13:55,340 16 times every earth day that means we 447 00:13:55,340 --> 00:13:58,540 16 times every earth day that means we see a sunrise and a sunset once every 90 448 00:13:58,540 --> 00:13:58,550 see a sunrise and a sunset once every 90 449 00:13:58,550 --> 00:14:02,650 see a sunrise and a sunset once every 90 minutes this could be a problem up here 450 00:14:02,650 --> 00:14:02,660 minutes this could be a problem up here 451 00:14:02,660 --> 00:14:05,080 minutes this could be a problem up here on the orbiter if I woke up when it was 452 00:14:05,080 --> 00:14:05,090 on the orbiter if I woke up when it was 453 00:14:05,090 --> 00:14:15,290 on the orbiter if I woke up when it was light and went to bed when it was dark 454 00:14:15,290 --> 00:14:15,300 455 00:14:15,300 --> 00:14:17,420 I'd be getting up and going to sleep 456 00:14:17,420 --> 00:14:17,430 I'd be getting up and going to sleep 457 00:14:17,430 --> 00:14:39,050 I'd be getting up and going to sleep every 45 minutes so instead we just plan 458 00:14:39,050 --> 00:14:39,060 every 45 minutes so instead we just plan 459 00:14:39,060 --> 00:14:49,689 every 45 minutes so instead we just plan out our days like we would on earth 460 00:14:49,689 --> 00:14:49,699 461 00:14:49,699 --> 00:14:52,669 another thing you should know is we just 462 00:14:52,669 --> 00:14:52,679 another thing you should know is we just 463 00:14:52,679 --> 00:14:54,199 another thing you should know is we just don't float around on the orbiter 464 00:14:54,199 --> 00:14:54,209 don't float around on the orbiter 465 00:14:54,209 --> 00:14:56,989 don't float around on the orbiter because there is no gravity we still 466 00:14:56,989 --> 00:14:56,999 because there is no gravity we still 467 00:14:56,999 --> 00:15:00,349 because there is no gravity we still feel Earth's gravity so why are we 468 00:15:00,349 --> 00:15:00,359 feel Earth's gravity so why are we 469 00:15:00,359 --> 00:15:05,160 feel Earth's gravity so why are we floating 470 00:15:05,160 --> 00:15:05,170 471 00:15:05,170 --> 00:15:08,819 because we're falling let's say this 472 00:15:08,819 --> 00:15:08,829 because we're falling let's say this 473 00:15:08,829 --> 00:15:12,239 because we're falling let's say this string is gravity and let's say this 474 00:15:12,239 --> 00:15:12,249 string is gravity and let's say this 475 00:15:12,249 --> 00:15:15,449 string is gravity and let's say this Apple is like a spaceship orbiting the 476 00:15:15,449 --> 00:15:15,459 Apple is like a spaceship orbiting the 477 00:15:15,459 --> 00:15:19,789 Apple is like a spaceship orbiting the Earth you see its gravity in our speed 478 00:15:19,789 --> 00:15:19,799 Earth you see its gravity in our speed 479 00:15:19,799 --> 00:15:23,539 Earth you see its gravity in our speed that keeps us in orbit without gravity 480 00:15:23,539 --> 00:15:23,549 that keeps us in orbit without gravity 481 00:15:23,549 --> 00:15:27,030 that keeps us in orbit without gravity we would fly off into space and never 482 00:15:27,030 --> 00:15:27,040 we would fly off into space and never 483 00:15:27,040 --> 00:15:28,400 we would fly off into space and never come back 484 00:15:28,400 --> 00:15:28,410 come back 485 00:15:28,410 --> 00:15:31,079 come back here's another example when I dropped 486 00:15:31,079 --> 00:15:31,089 here's another example when I dropped 487 00:15:31,089 --> 00:15:36,629 here's another example when I dropped this Apple on earth it falls when I drop 488 00:15:36,629 --> 00:15:36,639 this Apple on earth it falls when I drop 489 00:15:36,639 --> 00:15:38,519 this Apple on earth it falls when I drop an apple here on the Space Shuttle it 490 00:15:38,519 --> 00:15:38,529 an apple here on the Space Shuttle it 491 00:15:38,529 --> 00:15:40,650 an apple here on the Space Shuttle it falls - it just doesn't look like it's 492 00:15:40,650 --> 00:15:40,660 falls - it just doesn't look like it's 493 00:15:40,660 --> 00:15:43,280 falls - it just doesn't look like it's falling 494 00:15:43,280 --> 00:15:43,290 495 00:15:43,290 --> 00:15:45,320 and that's because we're all falling 496 00:15:45,320 --> 00:15:45,330 and that's because we're all falling 497 00:15:45,330 --> 00:15:48,910 and that's because we're all falling together the Apple me and the orbiter 498 00:15:48,910 --> 00:15:48,920 together the Apple me and the orbiter 499 00:15:48,920 --> 00:15:51,050 together the Apple me and the orbiter we're not falling towards the earth 500 00:15:51,050 --> 00:15:51,060 we're not falling towards the earth 501 00:15:51,060 --> 00:15:55,490 we're not falling towards the earth we're falling around it 502 00:15:55,490 --> 00:15:55,500 503 00:15:55,500 --> 00:15:57,500 let's imagine that we can send Bruce 504 00:15:57,500 --> 00:15:57,510 let's imagine that we can send Bruce 505 00:15:57,510 --> 00:16:05,819 let's imagine that we can send Bruce down to the nearest elevator on earth 506 00:16:05,819 --> 00:16:05,829 507 00:16:05,829 --> 00:16:08,129 the elevator is going to the top of a 508 00:16:08,129 --> 00:16:08,139 the elevator is going to the top of a 509 00:16:08,139 --> 00:16:16,290 the elevator is going to the top of a very tall building 510 00:16:16,290 --> 00:16:16,300 511 00:16:16,300 --> 00:16:18,870 suddenly when he reaches the top the 512 00:16:18,870 --> 00:16:18,880 suddenly when he reaches the top the 513 00:16:18,880 --> 00:16:21,840 suddenly when he reaches the top the cable breaks in the elevator car with 514 00:16:21,840 --> 00:16:21,850 cable breaks in the elevator car with 515 00:16:21,850 --> 00:16:24,210 cable breaks in the elevator car with Bruce in it begins to fall what will 516 00:16:24,210 --> 00:16:24,220 Bruce in it begins to fall what will 517 00:16:24,220 --> 00:16:27,240 Bruce in it begins to fall what will happen inside the elevator well since 518 00:16:27,240 --> 00:16:27,250 happen inside the elevator well since 519 00:16:27,250 --> 00:16:29,520 happen inside the elevator well since he's falling and the elevator is falling 520 00:16:29,520 --> 00:16:29,530 he's falling and the elevator is falling 521 00:16:29,530 --> 00:16:33,030 he's falling and the elevator is falling the same rate he starts to float his 522 00:16:33,030 --> 00:16:33,040 the same rate he starts to float his 523 00:16:33,040 --> 00:16:34,890 the same rate he starts to float his body isn't pushing on the inside of the 524 00:16:34,890 --> 00:16:34,900 body isn't pushing on the inside of the 525 00:16:34,900 --> 00:16:36,060 body isn't pushing on the inside of the elevator anymore 526 00:16:36,060 --> 00:16:36,070 elevator anymore 527 00:16:36,070 --> 00:16:41,130 elevator anymore he has no weight he's weightless if he 528 00:16:41,130 --> 00:16:41,140 he has no weight he's weightless if he 529 00:16:41,140 --> 00:16:43,290 he has no weight he's weightless if he had an apple with him it would float too 530 00:16:43,290 --> 00:16:43,300 had an apple with him it would float too 531 00:16:43,300 --> 00:16:45,420 had an apple with him it would float too just like the one in the orbiter because 532 00:16:45,420 --> 00:16:45,430 just like the one in the orbiter because 533 00:16:45,430 --> 00:16:48,000 just like the one in the orbiter because Bruce the Apple and the elevator would 534 00:16:48,000 --> 00:16:48,010 Bruce the Apple and the elevator would 535 00:16:48,010 --> 00:16:51,240 Bruce the Apple and the elevator would all be falling together it would be a 536 00:16:51,240 --> 00:16:51,250 all be falling together it would be a 537 00:16:51,250 --> 00:16:56,030 all be falling together it would be a fun ride until he hit the bottom and 538 00:16:56,030 --> 00:16:56,040 fun ride until he hit the bottom and 539 00:16:56,040 --> 00:16:58,500 fun ride until he hit the bottom and that's why things float around up here 540 00:16:58,500 --> 00:16:58,510 that's why things float around up here 541 00:16:58,510 --> 00:17:01,410 that's why things float around up here even really big things because we're all 542 00:17:01,410 --> 00:17:01,420 even really big things because we're all 543 00:17:01,420 --> 00:17:03,150 even really big things because we're all falling on a curved path around the 544 00:17:03,150 --> 00:17:03,160 falling on a curved path around the 545 00:17:03,160 --> 00:17:06,350 falling on a curved path around the earth 546 00:17:06,350 --> 00:17:06,360 547 00:17:06,360 --> 00:17:09,239 well now our work in space is done and 548 00:17:09,239 --> 00:17:09,249 well now our work in space is done and 549 00:17:09,249 --> 00:17:12,559 well now our work in space is done and it's time to go home so how do we do it 550 00:17:12,559 --> 00:17:12,569 it's time to go home so how do we do it 551 00:17:12,569 --> 00:17:16,949 it's time to go home so how do we do it well first we have to slow down let's go 552 00:17:16,949 --> 00:17:16,959 well first we have to slow down let's go 553 00:17:16,959 --> 00:17:20,669 well first we have to slow down let's go back to our imaginary Mountain here's 554 00:17:20,669 --> 00:17:20,679 back to our imaginary Mountain here's 555 00:17:20,679 --> 00:17:23,879 back to our imaginary Mountain here's our baseball orbiting the earth it's 556 00:17:23,879 --> 00:17:23,889 our baseball orbiting the earth it's 557 00:17:23,889 --> 00:17:27,329 our baseball orbiting the earth it's going around every 90 minutes - we know 558 00:17:27,329 --> 00:17:27,339 going around every 90 minutes - we know 559 00:17:27,339 --> 00:17:29,009 going around every 90 minutes - we know the other baseball's weren't able to get 560 00:17:29,009 --> 00:17:29,019 the other baseball's weren't able to get 561 00:17:29,019 --> 00:17:31,950 the other baseball's weren't able to get into orbit because we didn't throw them 562 00:17:31,950 --> 00:17:31,960 into orbit because we didn't throw them 563 00:17:31,960 --> 00:17:35,369 into orbit because we didn't throw them fast enough now to bring the baseball 564 00:17:35,369 --> 00:17:35,379 fast enough now to bring the baseball 565 00:17:35,379 --> 00:17:36,539 fast enough now to bring the baseball back for more of it 566 00:17:36,539 --> 00:17:36,549 back for more of it 567 00:17:36,549 --> 00:17:39,810 back for more of it all we have to do is slow it down just a 568 00:17:39,810 --> 00:17:39,820 all we have to do is slow it down just a 569 00:17:39,820 --> 00:17:52,010 all we have to do is slow it down just a bit watch what this looks like 570 00:17:52,010 --> 00:17:52,020 571 00:17:52,020 --> 00:17:56,600 those were maneuvering engines firing we 572 00:17:56,600 --> 00:17:56,610 those were maneuvering engines firing we 573 00:17:56,610 --> 00:18:00,530 those were maneuvering engines firing we use them to slow down 574 00:18:00,530 --> 00:18:00,540 575 00:18:00,540 --> 00:18:02,600 here's what it looks like from outside 576 00:18:02,600 --> 00:18:02,610 here's what it looks like from outside 577 00:18:02,610 --> 00:18:05,870 here's what it looks like from outside the orbiter when they fire they slow us 578 00:18:05,870 --> 00:18:05,880 the orbiter when they fire they slow us 579 00:18:05,880 --> 00:18:10,100 the orbiter when they fire they slow us down just enough to make a safe descent 580 00:18:10,100 --> 00:18:10,110 down just enough to make a safe descent 581 00:18:10,110 --> 00:18:13,940 down just enough to make a safe descent just like the baseball we've got to slow 582 00:18:13,940 --> 00:18:13,950 just like the baseball we've got to slow 583 00:18:13,950 --> 00:18:18,169 just like the baseball we've got to slow down to get out of little bit we glide 584 00:18:18,169 --> 00:18:18,179 down to get out of little bit we glide 585 00:18:18,179 --> 00:18:21,010 down to get out of little bit we glide back to earth under computer control 586 00:18:21,010 --> 00:18:21,020 back to earth under computer control 587 00:18:21,020 --> 00:18:23,419 back to earth under computer control until our altitude is about fifty 588 00:18:23,419 --> 00:18:23,429 until our altitude is about fifty 589 00:18:23,429 --> 00:18:26,780 until our altitude is about fifty thousand feet then the commander and 590 00:18:26,780 --> 00:18:26,790 thousand feet then the commander and 591 00:18:26,790 --> 00:18:29,990 thousand feet then the commander and pilot take over and land our space 592 00:18:29,990 --> 00:18:30,000 pilot take over and land our space 593 00:18:30,000 --> 00:19:02,600 pilot take over and land our space shuttle just like an airplane 594 00:19:02,600 --> 00:19:02,610 595 00:19:02,610 --> 00:19:05,790 space is great but a safe touchdown sure 596 00:19:05,790 --> 00:19:05,800 space is great but a safe touchdown sure 597 00:19:05,800 --> 00:19:08,520 space is great but a safe touchdown sure feels good after traveling two million 598 00:19:08,520 --> 00:19:08,530 feels good after traveling two million 599 00:19:08,530 --> 00:19:11,340 feels good after traveling two million miles in five days it's nice to be back 600 00:19:11,340 --> 00:19:11,350 miles in five days it's nice to be back 601 00:19:11,350 --> 00:19:18,360 miles in five days it's nice to be back home again so now we know that it takes 602 00:19:18,360 --> 00:19:18,370 home again so now we know that it takes 603 00:19:18,370 --> 00:19:20,730 home again so now we know that it takes a lot of power to push the orbiter 604 00:19:20,730 --> 00:19:20,740 a lot of power to push the orbiter 605 00:19:20,740 --> 00:19:22,950 a lot of power to push the orbiter through the atmosphere and into 606 00:19:22,950 --> 00:19:22,960 through the atmosphere and into 607 00:19:22,960 --> 00:19:27,210 through the atmosphere and into low-earth orbit in space we have to go 608 00:19:27,210 --> 00:19:27,220 low-earth orbit in space we have to go 609 00:19:27,220 --> 00:19:31,080 low-earth orbit in space we have to go very fast to stay in space and we have 610 00:19:31,080 --> 00:19:31,090 very fast to stay in space and we have 611 00:19:31,090 --> 00:19:33,540 very fast to stay in space and we have to slow down just enough to allow 612 00:19:33,540 --> 00:19:33,550 to slow down just enough to allow 613 00:19:33,550 --> 00:19:35,910 to slow down just enough to allow Earth's gravity to pull us out of orbit 614 00:19:35,910 --> 00:19:35,920 Earth's gravity to pull us out of orbit 615 00:19:35,920 --> 00:19:39,810 Earth's gravity to pull us out of orbit when we want to return that's how we get 616 00:19:39,810 --> 00:19:39,820 when we want to return that's how we get 617 00:19:39,820 --> 00:19:43,890 when we want to return that's how we get into space how we stay there and how we 618 00:19:43,890 --> 00:19:43,900 into space how we stay there and how we 619 00:19:43,900 --> 00:19:44,840 into space how we stay there and how we get back 620 00:19:44,840 --> 00:19:44,850 get back 621 00:19:44,850 --> 00:19:51,390 get back he might have 10987 thick we go for main 622 00:19:51,390 --> 00:19:51,400 he might have 10987 thick we go for main 623 00:19:51,400 --> 00:19:53,790 he might have 10987 thick we go for main engine start