1 00:00:03,304 --> 00:00:06,672 Narrator: Nasa has set its sights on mars. 2 00:00:08,676 --> 00:00:12,111 Its goal is to send humans to the red planet 3 00:00:12,113 --> 00:00:14,947 in the next 20 years. 4 00:00:14,949 --> 00:00:16,348 Looking up at mars in the sky, 5 00:00:16,350 --> 00:00:18,050 I really do feel like I'm looking at a place 6 00:00:18,052 --> 00:00:22,054 that someday there will be people walking around on it. 7 00:00:22,056 --> 00:00:25,824 It feels so much like earth in so many ways, 8 00:00:25,826 --> 00:00:29,361 and it's a place that really captures my imagination 9 00:00:29,363 --> 00:00:30,896 as a result. 10 00:00:30,898 --> 00:00:32,297 Oluseyi: It's the most earthlike environment 11 00:00:32,299 --> 00:00:34,066 we see in our solar system. 12 00:00:34,068 --> 00:00:36,035 So we're not going to leave it alone. 13 00:00:36,037 --> 00:00:38,771 We're going to try to do this. 14 00:00:38,773 --> 00:00:41,473 Narrator: But conquering our planetary neighbor 15 00:00:41,475 --> 00:00:45,344 is a tougher challenge than we ever thought possible. 16 00:00:45,346 --> 00:00:47,413 It's an isolated environment 17 00:00:47,415 --> 00:00:49,448 where a million things can go wrong, 18 00:00:49,450 --> 00:00:52,484 where there's absolutely no hope of rescue. 19 00:00:54,488 --> 00:00:56,121 Stricker: There are so many hurdles to overcome 20 00:00:56,123 --> 00:00:59,491 for human exploration of mars, and it makes it quite difficult. 21 00:00:59,493 --> 00:01:03,095 Sure, we can get there, but are we going to be in one piece? 22 00:01:03,097 --> 00:01:07,633 Sometimes it feels like mars is designed to keep us away. 23 00:01:07,635 --> 00:01:10,235 Narrator: Are we doomed to fail in this endeavor? 24 00:01:11,639 --> 00:01:14,640 -- Captions by vitac -- www.Vitac.Com 25 00:01:14,642 --> 00:01:17,676 captions paid for by discovery communications 26 00:01:22,783 --> 00:01:26,085 ♪ 27 00:01:26,087 --> 00:01:30,322 the red planet -- earth's neighbor 28 00:01:30,324 --> 00:01:36,028 and the destination of nasa's most ambitious mission to date. 29 00:01:36,030 --> 00:01:38,697 But this expedition will be harder 30 00:01:38,699 --> 00:01:41,233 than we ever thought possible. 31 00:01:41,235 --> 00:01:44,069 It hurts to think of how hard it is. 32 00:01:44,071 --> 00:01:47,739 It's the farthest a human being has ever been from the earth. 33 00:01:47,741 --> 00:01:50,209 We got to take every precaution 34 00:01:50,211 --> 00:01:53,045 narrator: As nasa's astronauts arrive at mars, 35 00:01:53,047 --> 00:01:55,948 they'll face a huge obstacle. 36 00:01:55,950 --> 00:01:59,485 Landing on the planet is a daunting task. 37 00:02:02,523 --> 00:02:07,693 In the past, mars hasn't always rolled out the welcome mat. 38 00:02:07,695 --> 00:02:10,462 Lanza: Mars is kind of like a graveyard for spacecraft. 39 00:02:10,464 --> 00:02:13,365 It's actually really hard to send something from earth 40 00:02:13,367 --> 00:02:15,801 and land it on mars. 41 00:02:15,803 --> 00:02:18,103 Narrator: This is how the european space agency 42 00:02:18,105 --> 00:02:22,174 hoped its $250 million schiaparelli lander 43 00:02:22,176 --> 00:02:24,877 would touch down in 2016... 44 00:02:26,881 --> 00:02:30,349 ...But the lander's systems got it wrong. 45 00:02:31,452 --> 00:02:36,355 The parachute detached early, sending the craft into free fall 46 00:02:36,357 --> 00:02:38,090 for 33 seconds. 47 00:02:40,327 --> 00:02:42,528 Schiaparelli smashed into the surface 48 00:02:42,530 --> 00:02:46,198 at 335 miles an hour, 49 00:02:46,200 --> 00:02:51,370 leaving a deep, black scar on the martian landscape. 50 00:02:51,372 --> 00:02:52,704 Thaller: It turns out that mars is actually 51 00:02:52,706 --> 00:02:55,507 a particularly difficult planet to land on. 52 00:02:55,509 --> 00:02:57,509 Even humanity's most brilliant engineers, 53 00:02:57,511 --> 00:02:59,645 we've got about a 50% success rate 54 00:02:59,647 --> 00:03:02,514 when it comes to landing on mars. 55 00:03:02,516 --> 00:03:05,851 Narrator: The red planet is littered with dead spacecraft 56 00:03:05,853 --> 00:03:07,986 that didn't stick the landing. 57 00:03:10,124 --> 00:03:13,358 And for nasa's first crewed descent to mars, 58 00:03:13,360 --> 00:03:17,963 the space agency must learn from these mistakes. 59 00:03:17,965 --> 00:03:20,899 But as the crew hurdles toward the surface 60 00:03:20,901 --> 00:03:22,668 they're battling the same problem 61 00:03:22,670 --> 00:03:25,437 as all the landers that failed before. 62 00:03:29,276 --> 00:03:30,676 The martian atmosphere 63 00:03:30,678 --> 00:03:33,145 is 100 times thinner than earth's 64 00:03:33,147 --> 00:03:34,913 so it can't provide the drag needed 65 00:03:34,915 --> 00:03:38,717 to slow a spacecraft down. 66 00:03:38,719 --> 00:03:40,252 So it's not like the earth, where you can have 67 00:03:40,254 --> 00:03:41,787 these big, giant parachutes 68 00:03:41,789 --> 00:03:44,856 that gently glide you down to the surface. 69 00:03:47,728 --> 00:03:51,396 You can use some of the air, but it's hard. 70 00:03:53,567 --> 00:03:55,801 Narrator: The red planet's thin atmosphere 71 00:03:55,803 --> 00:04:00,105 is a problem that's been billions of years in the making. 72 00:04:00,107 --> 00:04:01,406 Stricker: Mars doesn't have a large atmosphere 73 00:04:01,408 --> 00:04:04,643 because it's constantly being peeled away 74 00:04:04,645 --> 00:04:07,879 due to the lack of protection of a magnetic field. 75 00:04:10,351 --> 00:04:14,886 Narrator: The solar wind can strip away an atmosphere. 76 00:04:14,888 --> 00:04:18,824 On earth, a liquid metal core creates a magnetic field 77 00:04:18,826 --> 00:04:22,661 which shields the planet and helps maintain the atmosphere. 78 00:04:25,366 --> 00:04:29,134 Mars is different. 79 00:04:29,136 --> 00:04:31,503 4.5 billion years ago, 80 00:04:31,505 --> 00:04:35,574 mars and earth formed from dust and gas in space. 81 00:04:38,712 --> 00:04:42,781 Mars forms where building materials were scarce. 82 00:04:42,783 --> 00:04:46,618 Its growth was stunted. 83 00:04:46,620 --> 00:04:48,987 So mars is much smaller than the earth. 84 00:04:48,989 --> 00:04:51,023 It's a factor of 10 smaller than the earth, 85 00:04:51,025 --> 00:04:54,593 and that factor of 10 in mass is important. 86 00:04:54,595 --> 00:04:58,530 All of that extra mass allows the inside of the earth 87 00:04:58,532 --> 00:05:01,500 to stay warm and to have a core that's rotating, 88 00:05:01,502 --> 00:05:03,001 which generates a magnetic field. 89 00:05:04,772 --> 00:05:08,507 Narrator: 4 billion years ago, the churning heart of mars 90 00:05:08,509 --> 00:05:11,176 started to cool and solidify. 91 00:05:13,280 --> 00:05:18,417 With no hot core, there's no magnetic field being generated. 92 00:05:18,419 --> 00:05:22,020 All of the high-velocity charged particles coming from the sun 93 00:05:22,022 --> 00:05:25,857 pick away at the atmosphere and slowly tear it away. 94 00:05:27,895 --> 00:05:30,529 We know it's losing atmosphere every second 95 00:05:30,531 --> 00:05:31,863 due to the solar wind. 96 00:05:31,865 --> 00:05:34,666 So, you know, bye-bye atmosphere. 97 00:05:39,273 --> 00:05:43,875 ♪ 98 00:05:43,877 --> 00:05:46,445 narrator: With little martian atmosphere to work with, 99 00:05:46,447 --> 00:05:50,315 nasa had to be creative to get its crewless landers 100 00:05:50,317 --> 00:05:52,050 to the martian surface. 101 00:05:52,052 --> 00:05:57,322 ♪ 102 00:05:57,324 --> 00:06:00,592 in 2012, the revolutionary sky crane 103 00:06:00,594 --> 00:06:05,664 landed the curiosity rover using parachutes and retro rockets. 104 00:06:08,535 --> 00:06:11,203 Previous missions have used both a parachute 105 00:06:11,205 --> 00:06:13,572 and something else like a bouncy ball 106 00:06:13,574 --> 00:06:15,841 inflated around the spacecraft. 107 00:06:15,843 --> 00:06:21,513 ♪ 108 00:06:21,515 --> 00:06:24,149 I don't think a human crew is going to be too pleased 109 00:06:24,151 --> 00:06:25,751 if they're gonna be bouncing onto the surface 110 00:06:25,753 --> 00:06:29,020 in an airbag, rolling to a stop, right? 111 00:06:29,022 --> 00:06:34,826 Narrator: To land people on mars, nasa will need some new tricks. 112 00:06:34,828 --> 00:06:39,097 The 2020 rover will overcome the challenge with the advanced 113 00:06:39,099 --> 00:06:43,368 supersonic parachute inflation research experiment, 114 00:06:43,370 --> 00:06:46,438 a.S.P.I.R.E. 115 00:06:46,440 --> 00:06:50,742 It will rapidly slow down the craft 116 00:06:50,744 --> 00:06:53,912 with the force of an airplane jet engine. 117 00:06:56,617 --> 00:06:58,083 This is fine for the rover. 118 00:06:58,085 --> 00:06:59,751 It's actually gonna work no problem. 119 00:06:59,753 --> 00:07:02,854 But it's not going to work for people. 120 00:07:02,856 --> 00:07:05,223 Narrator: A human lander will weigh far more 121 00:07:05,225 --> 00:07:08,393 than the 2,300-pound rover. 122 00:07:08,395 --> 00:07:10,295 Not even supersonic parachutes 123 00:07:10,297 --> 00:07:12,764 could land a crew safely on mars. 124 00:07:15,102 --> 00:07:18,236 Nasa will need a new plan. 125 00:07:18,238 --> 00:07:22,274 One idea is to use the thin martian atmosphere 126 00:07:22,276 --> 00:07:24,209 in a unique way. 127 00:07:24,211 --> 00:07:26,545 There's an idea of coming in really fast, 128 00:07:26,547 --> 00:07:28,480 getting to the thick part of the atmosphere, 129 00:07:28,482 --> 00:07:30,649 and then going horizontal to the ground 130 00:07:30,651 --> 00:07:33,718 and gliding and losing your momentum that way. 131 00:07:37,858 --> 00:07:39,591 Narrator: As the astronauts descend, 132 00:07:39,593 --> 00:07:43,728 they tilt the nose of the lander towards the martian surface 133 00:07:43,730 --> 00:07:46,364 aiming for the thickest part of the atmosphere 134 00:07:46,366 --> 00:07:48,667 close to the ground. 135 00:07:48,669 --> 00:07:51,403 Then they pull up at the last second 136 00:07:51,405 --> 00:07:55,006 using friction from the atmosphere to slow the craft. 137 00:07:57,077 --> 00:08:01,079 Descent engines switch on for the final touchdown. 138 00:08:01,081 --> 00:08:08,353 ♪ 139 00:08:08,355 --> 00:08:09,821 radebaugh: Is this a crazy idea? 140 00:08:09,823 --> 00:08:12,524 I mean, yeah, it's a little bit weird. 141 00:08:12,526 --> 00:08:13,892 I don't know if we'd really think about it, 142 00:08:13,894 --> 00:08:15,260 doing something like this, 143 00:08:15,262 --> 00:08:18,530 but, I mean, you've got to think outside the box sometimes. 144 00:08:18,532 --> 00:08:22,167 Narrator: Right now, nasa's plans for landing a craft on mars 145 00:08:22,169 --> 00:08:24,269 are still on the drawing board. 146 00:08:24,271 --> 00:08:27,873 But even if they can get astronauts onto the surface, 147 00:08:27,875 --> 00:08:32,711 the thin atmosphere isn't done with them yet. 148 00:08:32,713 --> 00:08:35,413 It causes swirling dust storms 149 00:08:35,415 --> 00:08:38,049 that cover the planet's entire surface. 150 00:08:38,051 --> 00:08:39,651 Oluseyi: Mars doesn't just have dust devils. 151 00:08:39,653 --> 00:08:42,354 It has dust hell. 152 00:08:42,356 --> 00:08:47,325 Narrator: And these towering clouds have killed before. 153 00:08:58,038 --> 00:09:03,241 ♪ 154 00:09:03,243 --> 00:09:07,946 narrator: If nasa's astronauts arrive on mars as planned, in 2035, 155 00:09:07,948 --> 00:09:10,649 the settlers will find one of the red planet's 156 00:09:10,651 --> 00:09:13,718 biggest challenges is its dust. 157 00:09:17,124 --> 00:09:18,657 It's sticky, 158 00:09:18,659 --> 00:09:20,725 basically, light from the sun 159 00:09:20,727 --> 00:09:22,661 can give the stuff a static charge 160 00:09:22,663 --> 00:09:24,663 and then it clings to stuff. 161 00:09:24,665 --> 00:09:26,264 So it's not just a matter of, like, you know, 162 00:09:26,266 --> 00:09:29,034 standing on a doormat outside your your space habitat 163 00:09:29,036 --> 00:09:30,468 and shaking yourself off. 164 00:09:30,470 --> 00:09:31,636 Durda: It's gonna get in your space suit. 165 00:09:31,638 --> 00:09:33,305 It's gonna coat your visor. 166 00:09:33,307 --> 00:09:34,639 It's going to cover your solar panels. 167 00:09:36,209 --> 00:09:38,643 Plait: If you get it in your lungs, it's not a good thing. 168 00:09:38,645 --> 00:09:41,379 We have to figure out how to clear this stuff out. 169 00:09:43,150 --> 00:09:46,551 Man: 300 feet. [ speaks indistinctly ] 170 00:09:46,553 --> 00:09:50,055 narrator: Through the '60s and '70s, 171 00:09:50,057 --> 00:09:53,725 apollo astronauts walked on the moon. 172 00:09:53,727 --> 00:09:55,860 When they returned to their landing module, 173 00:09:55,862 --> 00:09:58,330 they brought moon dust back with them. 174 00:10:00,701 --> 00:10:04,436 The lunar dust clogged seals, caused equipment to overheat, 175 00:10:04,438 --> 00:10:07,505 and resulted in false instrument readings. 176 00:10:07,507 --> 00:10:10,709 It even made the astronauts sick. 177 00:10:10,711 --> 00:10:13,912 You don't want to be breathing in fine, dusty material 178 00:10:13,914 --> 00:10:16,615 by itself, you can get things like silicosis. 179 00:10:16,617 --> 00:10:19,284 It's, you know, almost basically a lung cancer 180 00:10:19,286 --> 00:10:21,152 that you can get just from breathing the dust itself. 181 00:10:21,154 --> 00:10:23,855 You don't want to do that. 182 00:10:23,857 --> 00:10:27,592 Narrator: The red planet is covered in sticky dust, 183 00:10:27,594 --> 00:10:32,130 and new research suggests it all came from one place... 184 00:10:35,736 --> 00:10:38,803 ...The medusae fossae formation. 185 00:10:38,805 --> 00:10:41,706 When the 600-mile-long volcanic deposit formed 186 00:10:41,708 --> 00:10:43,408 3 billion years ago, 187 00:10:43,410 --> 00:10:47,512 it was around half the size of the united states, 188 00:10:47,514 --> 00:10:50,382 but the martian winds have eroded this structure 189 00:10:50,384 --> 00:10:53,518 and spread the dust across the entire planet. 190 00:10:56,556 --> 00:10:58,823 When the wind whips up this dust, 191 00:10:58,825 --> 00:11:02,627 it can have disastrous consequences. 192 00:11:02,629 --> 00:11:06,064 Lanza: The real problem is just that all these fine particles 193 00:11:06,066 --> 00:11:08,199 get lofted into the atmosphere, 194 00:11:08,201 --> 00:11:11,169 and it takes a really long time for them to settle back out. 195 00:11:11,171 --> 00:11:13,872 And what the dust does is it just gets up in the sky 196 00:11:13,874 --> 00:11:17,208 and it sits there and sits there and sits there. 197 00:11:17,210 --> 00:11:20,645 Narrator: As more material gets lifted into the atmosphere, 198 00:11:20,647 --> 00:11:24,549 it forms huge dust storms. 199 00:11:24,551 --> 00:11:27,852 The storms are so large they block out the sunlight 200 00:11:27,854 --> 00:11:29,954 and cool the martian surface... 201 00:11:32,225 --> 00:11:34,025 ...Creating a temperature difference 202 00:11:34,027 --> 00:11:36,628 between the ground and atmosphere 203 00:11:36,630 --> 00:11:40,498 that causes winds to increase and the storms to grow. 204 00:11:43,470 --> 00:11:46,905 And nasa's opportunity rover knows firsthand 205 00:11:46,907 --> 00:11:50,675 the dangers of being trapped in one. 206 00:11:50,677 --> 00:11:54,946 Opportunity was a nasa rover sent to mars 207 00:11:54,948 --> 00:11:59,951 to hunt for signs of past water on the surface 208 00:11:59,953 --> 00:12:03,555 and potentially signs of past life. 209 00:12:03,557 --> 00:12:06,458 Lanza: This is a rover that we really worked with so long, 210 00:12:06,460 --> 00:12:08,927 knew so well, and who had come up with 211 00:12:08,929 --> 00:12:13,331 so many amazing new results from mars. 212 00:12:13,333 --> 00:12:15,533 Narrator: June 2018. 213 00:12:15,535 --> 00:12:18,570 Opportunity was 15 years into its mission... 214 00:12:20,340 --> 00:12:24,743 ...When giant clouds of dust appeared on the horizon. 215 00:12:24,745 --> 00:12:30,849 Nasa could only watch as the storm grew and grew. 216 00:12:30,851 --> 00:12:34,719 Once this dust storm coated the entire planet, 217 00:12:34,721 --> 00:12:36,521 it blocked the sun. 218 00:12:36,523 --> 00:12:40,058 And the sun was the source of opportunity's power. 219 00:12:40,060 --> 00:12:42,527 Opportunity works using solar panels, 220 00:12:42,529 --> 00:12:46,631 and so it gradually got less and less and less electricity. 221 00:12:46,633 --> 00:12:49,501 Narrator: For opportunity, there was no escape. 222 00:12:51,772 --> 00:12:53,605 Lost in the darkness, 223 00:12:53,607 --> 00:12:58,209 opportunity's power reserves slowly ran dry. 224 00:12:58,211 --> 00:13:02,213 The rover fell silent. 225 00:13:02,215 --> 00:13:04,749 We thought, well, maybe once the dust storm clears up 226 00:13:04,751 --> 00:13:07,485 the panels can fire up again and we can get it back, 227 00:13:07,487 --> 00:13:11,189 but it just never woke up. 228 00:13:11,191 --> 00:13:14,425 Narrator: If nasa's astronauts do make it to mars, 229 00:13:14,427 --> 00:13:18,296 the storms could damage more than the crew's power supply. 230 00:13:19,599 --> 00:13:21,599 [ thunder crashes ] 231 00:13:21,601 --> 00:13:26,838 when the storms begin to blow, they crackle with electricity. 232 00:13:26,840 --> 00:13:28,773 Just like you can create a static charge 233 00:13:28,775 --> 00:13:30,175 by rubbing your foot on the carpet 234 00:13:30,177 --> 00:13:32,110 or a balloon on your hair, 235 00:13:32,112 --> 00:13:36,514 this happens at large scale in these dust storms on mars. 236 00:13:36,516 --> 00:13:38,516 The sand grains rub up against each other, 237 00:13:38,518 --> 00:13:40,785 and that creates a static charge. 238 00:13:40,787 --> 00:13:44,856 So you get these electrical flows that occur. 239 00:13:44,858 --> 00:13:47,292 Durda: Here on earth, we see this in volcanic eruptions 240 00:13:47,294 --> 00:13:49,894 as the dust, the ash burbling out 241 00:13:49,896 --> 00:13:51,229 of one of these huge eruptions. 242 00:13:51,231 --> 00:13:54,232 You'll see lightning discharges in those volcanic plumes 243 00:13:54,234 --> 00:13:57,101 from this same charge transfer. 244 00:13:57,103 --> 00:13:59,470 Stricker: If you're in a place with a lot of electrostatic discharge, 245 00:13:59,472 --> 00:14:01,339 that means sparks are going to fly, 246 00:14:01,341 --> 00:14:05,777 which is really terrible for operating instruments. 247 00:14:05,779 --> 00:14:07,478 Narrator: To survive on mars, 248 00:14:07,480 --> 00:14:12,483 the settlers are going to need a protective shelter. 249 00:14:12,485 --> 00:14:15,820 The keyword to living on mars is protection -- 250 00:14:15,822 --> 00:14:17,755 protection from the cold, 251 00:14:17,757 --> 00:14:19,557 protection from the lack of atmosphere, 252 00:14:19,559 --> 00:14:22,293 protection from the radiation from space. 253 00:14:25,298 --> 00:14:27,432 Narrator: Nasa could build shelters, 254 00:14:27,434 --> 00:14:32,370 but martian history offers them a shortcut. 255 00:14:32,372 --> 00:14:34,372 Millions of years ago, 256 00:14:34,374 --> 00:14:38,409 the planet's volcanoes erupted huge amounts of lava. 257 00:14:42,716 --> 00:14:44,148 Radebaugh: But the silver lining is that, 258 00:14:44,150 --> 00:14:46,351 as the lava was flowing away, 259 00:14:46,353 --> 00:14:49,020 it did that through underground tubes. 260 00:14:49,022 --> 00:14:50,622 And then as the lava evacuated away, 261 00:14:50,624 --> 00:14:52,557 it left behind empty caverns, 262 00:14:52,559 --> 00:14:54,292 just like this really big lava tube 263 00:14:54,294 --> 00:14:57,295 that we're standing in right now. 264 00:14:57,297 --> 00:15:00,665 Narrator: Martian gravity is a third as strong as earth's 265 00:15:00,667 --> 00:15:04,135 thanks to the red planet's lower mass. 266 00:15:04,137 --> 00:15:06,671 So when martian lava flows underground, 267 00:15:06,673 --> 00:15:08,239 it meets less resistance 268 00:15:08,241 --> 00:15:11,609 and can carve out monstrous cave systems, 269 00:15:11,611 --> 00:15:14,012 natural astronaut shelters 270 00:15:14,014 --> 00:15:17,115 hidden away from the dust storms. 271 00:15:17,117 --> 00:15:20,451 If you actually then seal them, you can fill them with air. 272 00:15:20,453 --> 00:15:23,054 You've got a great place to live. 273 00:15:23,056 --> 00:15:26,858 These tunnels are ready-made for people to move into. 274 00:15:26,860 --> 00:15:29,994 We already have the keys. 275 00:15:29,996 --> 00:15:33,364 Narrator: But a lava tube may not be everyone's idea 276 00:15:33,366 --> 00:15:35,667 of home sweet home. 277 00:15:35,669 --> 00:15:38,169 Because they're a natural feature, 278 00:15:38,171 --> 00:15:39,904 you can't pick and choose where they are. 279 00:15:39,906 --> 00:15:42,573 You have to go to where they already exist. 280 00:15:45,545 --> 00:15:47,211 Narrator: Building their own shelters 281 00:15:47,213 --> 00:15:50,748 gives the astronauts more choices, 282 00:15:50,750 --> 00:15:53,484 and they can be built by robots 283 00:15:53,486 --> 00:15:57,121 before the settlers even arrive. 284 00:15:57,123 --> 00:15:59,891 Plait: And we could even send 3-d printers. 285 00:15:59,893 --> 00:16:02,727 I'm talking about something that actually uses the rock there 286 00:16:02,729 --> 00:16:04,696 and makes something like concrete, 287 00:16:04,698 --> 00:16:07,999 and it could build structures for us to live in. 288 00:16:08,001 --> 00:16:10,668 Narrator: Even with shelters, the settlers will still need 289 00:16:10,670 --> 00:16:14,005 to eat, breathe, and drink. 290 00:16:14,007 --> 00:16:17,475 But there is no food, no breathable oxygen, 291 00:16:17,477 --> 00:16:20,244 and no liquid water on mars. 292 00:16:20,246 --> 00:16:23,214 So even though mars is the closest friendly environment 293 00:16:23,216 --> 00:16:24,882 to life that there is to the earth, 294 00:16:24,884 --> 00:16:26,985 it's really not all that friendly. 295 00:16:26,987 --> 00:16:30,321 Narrator: Without easy access to the essentials of life, 296 00:16:30,323 --> 00:16:33,624 will settling on mars be possible? 297 00:16:44,637 --> 00:16:48,506 ♪ 298 00:16:48,508 --> 00:16:51,309 narrator: Humans have evolved to life on earth. 299 00:16:53,947 --> 00:16:58,950 We have oxygen to breathe, water to drink, and food to eat -- 300 00:16:58,952 --> 00:17:01,252 everything we need to survive. 301 00:17:04,657 --> 00:17:06,157 Compared to earth, 302 00:17:06,159 --> 00:17:10,194 life on mars is a recipe for disaster. 303 00:17:10,196 --> 00:17:13,197 If you look at it as a human being who wants to live there, 304 00:17:13,199 --> 00:17:14,799 yeah, this is an alien world 305 00:17:14,801 --> 00:17:17,435 that's going to try to kill you at every step. 306 00:17:17,437 --> 00:17:19,370 Stricker: It's far away. It's cold. 307 00:17:19,372 --> 00:17:21,005 There are just so many reasons why 308 00:17:21,007 --> 00:17:23,975 we really wouldn't be happy campers on mars. 309 00:17:23,977 --> 00:17:25,209 So why on earth are we talking 310 00:17:25,211 --> 00:17:27,578 about sending people there? 311 00:17:27,580 --> 00:17:31,049 Well, the next closest planet, venus, it's way worse. 312 00:17:31,051 --> 00:17:33,451 Its surface is super hot. 313 00:17:33,453 --> 00:17:36,287 It's got horrible chemicals in the atmosphere. 314 00:17:36,289 --> 00:17:37,488 So in comparison, 315 00:17:37,490 --> 00:17:39,724 mars looks like a great, great place to visit. 316 00:17:39,726 --> 00:17:42,794 It's close, it's relatively earthlike, 317 00:17:42,796 --> 00:17:44,829 and although there are many challenges 318 00:17:44,831 --> 00:17:48,199 they're challenges that we could overcome. 319 00:17:48,201 --> 00:17:49,500 Narrator: To settle on mars, 320 00:17:49,502 --> 00:17:53,404 nasa's astronauts need a few essentials. 321 00:17:53,406 --> 00:17:56,474 If we want to live there, short term or long term, 322 00:17:56,476 --> 00:17:58,042 you know, what do you need physically? 323 00:17:58,044 --> 00:18:02,814 Well, you need air. You need water. You need food. 324 00:18:02,816 --> 00:18:05,683 Those are all things that we can bring with us, 325 00:18:05,685 --> 00:18:11,622 but it's a lot easier if they exist there on mars. 326 00:18:11,624 --> 00:18:14,425 Narrator: The settlers will need to grow their own food, 327 00:18:14,427 --> 00:18:19,163 but the martian ground is poisonous. 328 00:18:19,165 --> 00:18:20,865 Mars' dust looks really benign. 329 00:18:20,867 --> 00:18:23,468 It looks kind of like dust you would find in southern utah. 330 00:18:23,470 --> 00:18:24,969 But it turns out it contains 331 00:18:24,971 --> 00:18:27,271 a lot of something called perchlorate, 332 00:18:27,273 --> 00:18:30,308 and these materials are really toxic to human life. 333 00:18:30,310 --> 00:18:32,543 [ thunder crashing ] 334 00:18:32,545 --> 00:18:36,080 narrator: Perchlorates are chemicals formed by electricity 335 00:18:36,082 --> 00:18:39,016 produced in martian dust storms. 336 00:18:39,018 --> 00:18:43,921 And they make up about 1% of the martian soil 337 00:18:43,923 --> 00:18:45,590 which doesn't sound like much, 338 00:18:45,592 --> 00:18:48,092 but this could be a significant problem 339 00:18:48,094 --> 00:18:51,929 for any humans living on the surface of the red planet. 340 00:18:51,931 --> 00:18:56,234 Narrator: Food grown in the martian dirt will absorb the perchlorates, 341 00:18:56,236 --> 00:19:00,471 posing a health hazard for the astronauts. 342 00:19:00,473 --> 00:19:02,773 But that's not all. 343 00:19:02,775 --> 00:19:05,510 Direct exposure to the toxic soil 344 00:19:05,512 --> 00:19:07,979 will make astronauts very sick. 345 00:19:10,416 --> 00:19:11,849 One of the effects that perchlorates 346 00:19:11,851 --> 00:19:15,887 have biologically in our bodies is to sort of mess with 347 00:19:15,889 --> 00:19:19,490 and alter the function of our thyroid glands. 348 00:19:19,492 --> 00:19:23,094 Narrator: Astronauts would get rashes and feel nauseous. 349 00:19:23,096 --> 00:19:27,932 Extended exposure to the dirt could even kill them. 350 00:19:27,934 --> 00:19:29,300 And mars is not the sort of place 351 00:19:29,302 --> 00:19:32,103 where you would ever want to get seriously ill, 352 00:19:32,105 --> 00:19:34,305 millions of miles from all the hospitals 353 00:19:34,307 --> 00:19:36,774 and health care of the earth. 354 00:19:38,711 --> 00:19:42,613 Narrator: There are ideas of how to clean the poisonous soil 355 00:19:42,615 --> 00:19:44,749 using water or bacteria, 356 00:19:44,751 --> 00:19:48,186 but the technology is not yet ready. 357 00:19:48,188 --> 00:19:52,623 The first settlers will need to find a safer way to grow food, 358 00:19:52,625 --> 00:19:57,395 and nasa has the solution -- hydroponics. 359 00:19:57,397 --> 00:19:59,564 Hydroponics will provide all the food 360 00:19:59,566 --> 00:20:02,300 a martian settler might need. 361 00:20:02,302 --> 00:20:07,471 Instead of growing in soil, the settlers grow crops in water 362 00:20:07,473 --> 00:20:10,708 so all you need to do is bring the seeds or the plants 363 00:20:10,710 --> 00:20:13,711 and then have them grow right there in water. 364 00:20:13,713 --> 00:20:17,248 But if we decide to grow our crops hydroponically on mars, 365 00:20:17,250 --> 00:20:18,482 then we still have this problem 366 00:20:18,484 --> 00:20:22,220 of needing lots and lots of water. 367 00:20:22,222 --> 00:20:24,655 Narrator: Before astronauts water their plants, 368 00:20:24,657 --> 00:20:27,558 they'll need water to drink, 369 00:20:27,560 --> 00:20:33,564 and mars hasn't had running water for millions of years. 370 00:20:33,566 --> 00:20:34,966 We've all seen the movies of people 371 00:20:34,968 --> 00:20:37,235 stranded in different places and having to survive 372 00:20:37,237 --> 00:20:39,403 and they can last for months without food. 373 00:20:39,405 --> 00:20:42,940 But a human cannot last beyond three days without water. 374 00:20:47,547 --> 00:20:50,281 Narrator: Astronauts on the international space station 375 00:20:50,283 --> 00:20:57,421 recycle water from bathing, breath, urine, and sweat, 376 00:20:57,423 --> 00:21:01,926 but they still need 1,500 gallons sent up each year. 377 00:21:01,928 --> 00:21:04,762 Each delivery weighs over six tons. 378 00:21:07,133 --> 00:21:09,233 Transporting water to mars 379 00:21:09,235 --> 00:21:12,303 will add a lot of weight to the manifest. 380 00:21:12,305 --> 00:21:14,672 You have to use fuel to launch it 381 00:21:14,674 --> 00:21:16,540 but then you also have to use more fuel 382 00:21:16,542 --> 00:21:18,276 to launch the weight of the other fuel, 383 00:21:18,278 --> 00:21:20,244 and so on and so on. 384 00:21:20,246 --> 00:21:23,781 You have to keep to an absolute minimum 385 00:21:23,783 --> 00:21:26,484 the amount of weight you try to launch from earth. 386 00:21:26,486 --> 00:21:29,987 Narrator: So if nasa wants to set up residence on mars, 387 00:21:29,989 --> 00:21:34,125 astronauts will need to find a water source. 388 00:21:34,127 --> 00:21:38,029 Even though no liquid water exists on the planet's surface, 389 00:21:38,031 --> 00:21:41,365 there are other places to look. 390 00:21:41,367 --> 00:21:43,834 It turns out there is a lot of water on mars. 391 00:21:43,836 --> 00:21:46,170 It's trapped underneath the ground beneath the dirt 392 00:21:46,172 --> 00:21:47,905 and the soils at high latitudes. 393 00:21:47,907 --> 00:21:51,676 It's also found in huge volumes up at the polar ice caps. 394 00:21:54,447 --> 00:21:56,080 Plait: Ice -- you melt, and it becomes water. 395 00:21:56,082 --> 00:21:57,481 You can drink it. Yay. 396 00:21:57,483 --> 00:21:59,483 You can grow plants and do things like that. 397 00:21:59,485 --> 00:22:02,386 In fact, if you were to melt all of mars' polar ice, 398 00:22:02,388 --> 00:22:06,957 then you would be able to cover the globe in water 399 00:22:06,959 --> 00:22:11,429 plait: So ice is an extremely important thing to have access to. 400 00:22:11,431 --> 00:22:15,299 So if we do go to mars to explore and live there, 401 00:22:15,301 --> 00:22:20,404 following the ice is the way it's going to go. 402 00:22:20,406 --> 00:22:23,274 Narrator: Even if nasa's astronauts can turn the martian ice 403 00:22:23,276 --> 00:22:28,045 into drinking water, without another resource, 404 00:22:28,047 --> 00:22:31,882 settlers will be dead in three minutes -- 405 00:22:31,884 --> 00:22:34,785 oxygen to breathe. 406 00:22:34,787 --> 00:22:37,621 There is oxygen on mars, but it's not in the air. 407 00:22:37,623 --> 00:22:38,856 You can't breathe it. 408 00:22:38,858 --> 00:22:42,426 It's bound up in the dirt and combined with iron 409 00:22:42,428 --> 00:22:47,198 to make iron oxide, giving it its characteristic red color. 410 00:22:47,200 --> 00:22:49,266 And so we need to bring it with us, 411 00:22:49,268 --> 00:22:50,935 and that's a huge amount to bring, 412 00:22:50,937 --> 00:22:55,373 or we need to make it at mars, and that's really difficult. 413 00:22:55,375 --> 00:22:59,076 Narrator: We can deliver oxygen to the I.S.S., 414 00:22:59,078 --> 00:23:01,812 but the trip to mars is long 415 00:23:01,814 --> 00:23:05,883 so there will be few supply missions. 416 00:23:05,885 --> 00:23:08,085 Once you're on mars, you can't pull out your app 417 00:23:08,087 --> 00:23:10,821 and order an oxygen delivery to your door. 418 00:23:10,823 --> 00:23:13,224 You got to take it with you, and that's a lot of oxygen. 419 00:23:14,961 --> 00:23:17,061 Narrator: Nasa astronauts will need a way 420 00:23:17,063 --> 00:23:19,830 to make oxygen on the red planet, 421 00:23:19,832 --> 00:23:22,933 and the space agency is working on a solution. 422 00:23:26,406 --> 00:23:30,241 When their 2020 rover arrives on mars, it will carry out 423 00:23:30,243 --> 00:23:35,513 the mars oxygen in-situ resource utilization experiment, 424 00:23:35,515 --> 00:23:38,282 or m.O.X.I.E. 425 00:23:38,284 --> 00:23:42,686 M.O.X.I.E. Will take carbon dioxide from the martian air. 426 00:23:42,688 --> 00:23:47,858 And use electricity to split that co2 and release oxygen 427 00:23:47,860 --> 00:23:51,262 that astronauts could breathe in the future. 428 00:23:51,264 --> 00:23:54,665 Narrator: This test will create oxygen on another planet 429 00:23:54,667 --> 00:23:56,300 for the first time, 430 00:23:56,302 --> 00:24:00,604 but m.O.X.I.E. Can't make enough for a crewed mission to mars. 431 00:24:00,606 --> 00:24:02,039 M.O.X.I.E. Will be able to make 432 00:24:02,041 --> 00:24:06,610 about half a pound of oxygen per day, 433 00:24:06,612 --> 00:24:11,549 which is only enough to keep a human alive for about six hours. 434 00:24:11,551 --> 00:24:15,352 Narrator: Nasa needs to significantly scale up the technology 435 00:24:15,354 --> 00:24:19,323 to support a whole crew on mars. 436 00:24:19,325 --> 00:24:24,562 But even if the astronauts can survive on the red planet, 437 00:24:24,564 --> 00:24:27,832 can they actually reach it? 438 00:24:27,834 --> 00:24:31,535 Radebaugh: This is a long trip in a bathtub with three other people. 439 00:24:31,537 --> 00:24:33,237 It's really challenging. 440 00:24:33,239 --> 00:24:35,039 I think we're still asking ourselves this question, 441 00:24:35,041 --> 00:24:36,273 how will we do it? 442 00:24:50,189 --> 00:24:53,324 ♪ 443 00:24:53,326 --> 00:24:57,995 narrator: Nasa plans to put boots on mars. 444 00:24:57,997 --> 00:25:01,999 To achieve this, you need to carry a lot of stuff. 445 00:25:03,636 --> 00:25:06,337 Sutter: You need oxygen, you need medical supplies, 446 00:25:06,339 --> 00:25:08,239 you need food, you need stores of water, 447 00:25:08,241 --> 00:25:11,208 you need some fuel if you want to come back, 448 00:25:11,210 --> 00:25:16,547 and all this has to be packed into an incredibly tiny volume. 449 00:25:18,351 --> 00:25:21,252 Narrator: Nasa's solution -- orion, 450 00:25:21,254 --> 00:25:27,024 a 28-ton spacecraft nearly twice the mass of a school bus. 451 00:25:27,026 --> 00:25:29,159 The rocket that launches orion 452 00:25:29,161 --> 00:25:33,931 will need to produce millions of pounds of thrust, 453 00:25:33,933 --> 00:25:36,066 and that is a problem. 454 00:25:36,068 --> 00:25:37,801 If we decided tomorrow, like, 455 00:25:37,803 --> 00:25:40,571 "hey, you know what? Let's go to mars." 456 00:25:40,573 --> 00:25:41,839 we can't. 457 00:25:41,841 --> 00:25:43,707 We don't have powerful-enough rockets to do it. 458 00:25:45,778 --> 00:25:49,446 Narrator: In 1969, nasa's saturn v rocket 459 00:25:49,448 --> 00:25:52,049 fired apollo astronauts to the moon 460 00:25:52,051 --> 00:25:55,486 with 7.6 million pounds of thrust. 461 00:25:55,488 --> 00:25:59,590 That's the power of more than 34 jumbo jets. 462 00:25:59,592 --> 00:26:03,794 A saturn v could have sent astronauts to mars. 463 00:26:03,796 --> 00:26:07,431 Not anymore. We stopped making them. 464 00:26:07,433 --> 00:26:09,867 Narrator: To break free from earth's gravity, 465 00:26:09,869 --> 00:26:14,071 the space rocket must travel at 25,000 miles an hour. 466 00:26:15,308 --> 00:26:16,640 To achieve that, 467 00:26:16,642 --> 00:26:20,711 nasa is building the most powerful rocket in the world. 468 00:26:20,713 --> 00:26:23,280 The space launch system, or s.L.S., is the rocket 469 00:26:23,282 --> 00:26:26,183 that's being designed to carry orion off of earth 470 00:26:26,185 --> 00:26:28,218 and beyond low earth orbit. 471 00:26:28,220 --> 00:26:31,388 Sutter: And the philosophy is, "hey, remember those big rockets 472 00:26:31,390 --> 00:26:33,857 that we used to make back in the '60s and stuff? 473 00:26:33,859 --> 00:26:36,894 Let's do that again but more so." 474 00:26:39,231 --> 00:26:40,397 radebaugh: It's really big. 475 00:26:40,399 --> 00:26:42,166 It's larger than the saturn v rocket 476 00:26:42,168 --> 00:26:44,702 that was built to carry the apollo spacecraft 477 00:26:44,704 --> 00:26:49,006 and is therefore going to be the largest rocket built. 478 00:26:49,008 --> 00:26:51,542 Narrator: The space launch system will be taller 479 00:26:51,544 --> 00:26:53,243 than the statue of liberty. 480 00:26:53,245 --> 00:26:56,046 Its gargantuan engines will thrust the rocket 481 00:26:56,048 --> 00:26:57,715 through the atmosphere 482 00:26:57,717 --> 00:27:01,685 with the horsepower of 160,000 corvettes, 483 00:27:01,687 --> 00:27:05,990 producing 8.8 million pounds of thrust. 484 00:27:05,992 --> 00:27:11,128 The s.L.S. Will be able to blast the orion capsule into space 485 00:27:11,130 --> 00:27:14,264 and send it on its way to mars. 486 00:27:17,136 --> 00:27:21,171 Unfortunately, the rocket has fallen behind schedule. 487 00:27:21,173 --> 00:27:26,010 Its maiden test flight was set for December of 2017. 488 00:27:26,012 --> 00:27:30,714 Now it's scheduled for the end of 2020. 489 00:27:30,716 --> 00:27:34,551 Critics see the s.L.S. As a waste of money, 490 00:27:34,553 --> 00:27:38,689 with the project reported to be billions of dollars over budget. 491 00:27:41,460 --> 00:27:44,428 It's still hoped nasa's space-launch system 492 00:27:44,430 --> 00:27:49,400 will go to mars in the 2030s. 493 00:27:49,402 --> 00:27:52,436 But even though the red planet is our neighbor, 494 00:27:52,438 --> 00:27:56,607 the timing of our visit will be complicated. 495 00:27:56,609 --> 00:27:58,208 Plait: If you're planning a family vacation 496 00:27:58,210 --> 00:28:00,277 and you want to get in the car, it's easy, right? 497 00:28:00,279 --> 00:28:02,646 You look at a map and you say I live in city "a" 498 00:28:02,648 --> 00:28:03,847 and I want to go to city "b" 499 00:28:03,849 --> 00:28:05,883 and I'll just take the highways there." 500 00:28:05,885 --> 00:28:07,017 well, great. 501 00:28:07,019 --> 00:28:09,486 Now imagine that city "a" is moving this way 502 00:28:09,488 --> 00:28:10,854 at 50 miles per hour, 503 00:28:10,856 --> 00:28:13,791 and this city is moving this way at 200 miles per hour. 504 00:28:13,793 --> 00:28:14,925 Now what do you do? 505 00:28:14,927 --> 00:28:17,227 Well, that is a very small problem 506 00:28:17,229 --> 00:28:19,730 compared to getting to another planet. 507 00:28:19,732 --> 00:28:21,398 The timeline of a mars mission, 508 00:28:21,400 --> 00:28:22,666 the scheduling, if you will, 509 00:28:22,668 --> 00:28:24,368 is all governed by celestial mechanics, 510 00:28:24,370 --> 00:28:25,569 the orbits of the planets. 511 00:28:25,571 --> 00:28:27,971 It's not just you pick a time to go to mars 512 00:28:27,973 --> 00:28:29,940 randomly whenever you feel like going. 513 00:28:29,942 --> 00:28:31,075 You've literally got to wait 514 00:28:31,077 --> 00:28:33,911 for the planets to be aligned, right? 515 00:28:33,913 --> 00:28:36,246 Thaller: On average, the distance from the earth to mars 516 00:28:36,248 --> 00:28:38,615 is about 140 million miles. 517 00:28:38,617 --> 00:28:40,117 But this is changing all the time 518 00:28:40,119 --> 00:28:42,653 because we are both plants that are orbiting the sun. 519 00:28:42,655 --> 00:28:45,723 So about the closest that earth ever comes to mars 520 00:28:45,725 --> 00:28:48,559 is a distance of about 35 million miles. 521 00:28:51,997 --> 00:28:54,498 Durda: But on other times when we're on the opposite side 522 00:28:54,500 --> 00:28:55,766 of the sun from mars, 523 00:28:55,768 --> 00:28:59,002 it can be as much as 250 million miles. 524 00:28:59,004 --> 00:29:00,204 Narrator: Launching near the time 525 00:29:00,206 --> 00:29:05,409 of mars' closest approach shortens the journey 526 00:29:05,411 --> 00:29:08,746 so nasa can save on fuel and resources, 527 00:29:08,748 --> 00:29:12,683 boosting the mission's chances of success, 528 00:29:12,685 --> 00:29:18,555 but this planetary alignment only happens every 26 months. 529 00:29:18,557 --> 00:29:21,725 So if nasa misses a launch window, 530 00:29:21,727 --> 00:29:25,429 it'll have to wait over two years for another go. 531 00:29:25,431 --> 00:29:28,766 But simply picking the right time isn't enough. 532 00:29:32,338 --> 00:29:35,873 Mars and the earth are both orbiting the sun. 533 00:29:35,875 --> 00:29:40,844 So orion can't fly in a straight line to mars. 534 00:29:40,846 --> 00:29:45,949 Instead, it'll use what's known as a hohmann transfer. 535 00:29:45,951 --> 00:29:49,686 What we want to do is sort of put ourselves on our spacecraft 536 00:29:49,688 --> 00:29:51,421 in orbit around the sun 537 00:29:51,423 --> 00:29:54,124 so we might start right here on earth, 538 00:29:54,126 --> 00:29:55,826 launch our spacecraft, 539 00:29:55,828 --> 00:29:59,797 and, essentially, we just make a nice, gentle arc 540 00:29:59,799 --> 00:30:02,199 that's arcing around the sun 541 00:30:02,201 --> 00:30:05,002 so that it can naturally slide into this orbit 542 00:30:05,004 --> 00:30:07,504 and then end up on mars. 543 00:30:07,506 --> 00:30:11,141 Narrator: The journey will take around 10 months. 544 00:30:11,143 --> 00:30:14,144 To get there quicker means burning more fuel, 545 00:30:14,146 --> 00:30:16,446 which is not an option. 546 00:30:16,448 --> 00:30:20,083 The hohmann transfer keeps fuel usage low 547 00:30:20,085 --> 00:30:22,152 by putting the craft in an orbit 548 00:30:22,154 --> 00:30:25,823 that gradually intersects with the orbit of mars 549 00:30:25,825 --> 00:30:29,326 before being captured by the red planet's gravity. 550 00:30:31,030 --> 00:30:34,865 But the crew will need to get their direction just right. 551 00:30:34,867 --> 00:30:36,800 Durda: The way the orbits work, 552 00:30:36,802 --> 00:30:39,303 you've got to aim a little bit different direction 553 00:30:39,305 --> 00:30:41,538 from where mars appears to be now. 554 00:30:41,540 --> 00:30:44,341 You got to aim for where it's going to be when you get there. 555 00:30:44,343 --> 00:30:46,643 This has to happen so that it can naturally slide 556 00:30:46,645 --> 00:30:50,113 into this orbit and then end up on mars. 557 00:30:50,115 --> 00:30:51,348 If we miss that precision, 558 00:30:51,350 --> 00:30:54,384 then we just could end up hurtling out into space. 559 00:30:56,655 --> 00:30:59,289 Narrator: Even if nasa hit their target. 560 00:30:59,291 --> 00:31:03,527 The crew still has a long 10-month journey in space. 561 00:31:04,563 --> 00:31:08,565 The human body is just simply not designed 562 00:31:08,567 --> 00:31:10,834 for long-duration space travel. 563 00:31:10,836 --> 00:31:13,570 Narrator: Space travel can destroy bones, 564 00:31:13,572 --> 00:31:17,074 weaken heart muscles, and even mess with the mind. 565 00:31:18,878 --> 00:31:22,579 Could a cruise survive the journey to the red planet? 566 00:31:34,093 --> 00:31:37,728 ♪ 567 00:31:37,730 --> 00:31:42,065 narrator: Nasa plans to put humans on mars in the 2030s. 568 00:31:44,670 --> 00:31:48,138 Rocket technology will be pushed to its limits. 569 00:31:50,209 --> 00:31:55,646 But the greatest hurdle is our own fragile bodies 570 00:31:55,648 --> 00:31:58,916 out there in a spacecraft between the planets, 571 00:31:58,918 --> 00:32:00,117 all bets are off. 572 00:32:00,119 --> 00:32:04,321 It's going to be a dangerous trip. 573 00:32:04,323 --> 00:32:07,424 Irwin: Both hands down to about the fourth rung up. 574 00:32:07,426 --> 00:32:10,327 Narrator: When astronaut james irwin stood on the moon, 575 00:32:10,329 --> 00:32:12,896 his heart beat irregularly. 576 00:32:15,334 --> 00:32:17,834 Back on earth, irwin suffered heart attacks, 577 00:32:17,836 --> 00:32:21,171 which eventually proved fatal. 578 00:32:21,173 --> 00:32:24,174 A 2016 study found that apollo lunar astronauts 579 00:32:24,176 --> 00:32:27,377 are four to five times more likely to die 580 00:32:27,379 --> 00:32:29,680 from cardiovascular disease 581 00:32:29,682 --> 00:32:35,252 than astronauts who never left earth's orbit. 582 00:32:35,254 --> 00:32:39,690 One cause could be deep-space radiation. 583 00:32:39,692 --> 00:32:41,658 And the radiation in outer space 584 00:32:41,660 --> 00:32:45,128 won't just be damaging the heart muscles 585 00:32:45,130 --> 00:32:46,964 but also the nervous system 586 00:32:46,966 --> 00:32:49,866 and astronauts' brains in outer space. 587 00:32:52,071 --> 00:32:54,938 Narrator: Astronauts heading to mars will face radiation 588 00:32:54,940 --> 00:32:58,342 created in the core of stars. 589 00:32:58,344 --> 00:33:02,045 Some comes from our sun when solar ejections 590 00:33:02,047 --> 00:33:05,282 throw out streams of deadly charged particles. 591 00:33:05,284 --> 00:33:11,254 ♪ 592 00:33:11,256 --> 00:33:16,159 there are also cosmic rays from outside the solar system. 593 00:33:16,161 --> 00:33:20,764 Created in supernovas, the death of giant stars, 594 00:33:20,766 --> 00:33:23,500 these energetic particles 595 00:33:23,502 --> 00:33:27,137 race through the galaxy at close to the speed of light. 596 00:33:27,139 --> 00:33:29,673 And you don't want to be exposed to too many of them. 597 00:33:29,675 --> 00:33:32,309 In low doses, it's not a problem at all, really. 598 00:33:32,311 --> 00:33:35,312 But in high enough doses, these things penetrate ourselves 599 00:33:35,314 --> 00:33:37,748 and damage our dna and over the long term 600 00:33:37,750 --> 00:33:41,952 can cause really bad damage to human bodies in space. 601 00:33:44,757 --> 00:33:50,627 Narrator: The longer you stay in space, the greater the danger. 602 00:33:50,629 --> 00:33:52,095 Durda: Remember, our missions to the moon 603 00:33:52,097 --> 00:33:53,663 were on the order of a week or two. 604 00:33:53,665 --> 00:33:56,400 A mission to mars, at the minimum, 605 00:33:56,402 --> 00:33:58,201 is going to be something like two 606 00:33:58,203 --> 00:34:00,904 or two-and-a-half years, probably. 607 00:34:00,906 --> 00:34:07,144 Narrator: These cosmic bullets can cause mutations and even cancer. 608 00:34:07,146 --> 00:34:11,281 New research from 2019 suggests space radiation 609 00:34:11,283 --> 00:34:13,183 will cause memory loss 610 00:34:13,185 --> 00:34:17,687 in one to three astronauts on a mission to mars. 611 00:34:17,689 --> 00:34:18,889 Darnell: And it's not just a problem 612 00:34:18,891 --> 00:34:21,024 of forgetting where you've left your keys. 613 00:34:21,026 --> 00:34:23,627 Trying to come back in through the airlock, you do not want 614 00:34:23,629 --> 00:34:26,163 to be forgetting emergency procedures. 615 00:34:26,165 --> 00:34:28,565 So we're going to have to really consider, 616 00:34:28,567 --> 00:34:30,934 how do we mitigate the effects of this radiation 617 00:34:30,936 --> 00:34:34,204 to make it possible for people to go to mars 618 00:34:34,206 --> 00:34:37,441 and actually spend some time without being ill? 619 00:34:37,443 --> 00:34:41,745 Narrator: So the ship needs to protect the astronauts. 620 00:34:41,747 --> 00:34:43,146 Plait: Well, you think, "well, I would just, 621 00:34:43,148 --> 00:34:45,315 I don't know, build a spaceship out of really thick lead. 622 00:34:45,317 --> 00:34:47,517 Like, well, that weighs a lot, and it turns out 623 00:34:47,519 --> 00:34:50,253 lead doesn't protect you from this kind of radiation. 624 00:34:50,255 --> 00:34:52,289 You need something else. 625 00:34:52,291 --> 00:34:53,723 Well, there is something else 626 00:34:53,725 --> 00:34:55,125 that protects you from this radiation, 627 00:34:55,127 --> 00:34:56,693 and that's water. 628 00:34:56,695 --> 00:34:58,061 We need to bring lots and lots of water 629 00:34:58,063 --> 00:34:59,863 to drink and cook with. 630 00:34:59,865 --> 00:35:02,566 And if we just place that water in a layer 631 00:35:02,568 --> 00:35:06,203 around our spacecraft, that can absorb the cosmic rays. 632 00:35:06,205 --> 00:35:08,872 You might think, well, you're drinking the very water 633 00:35:08,874 --> 00:35:12,409 that using to stop the radiation that's causing damage to us 634 00:35:12,411 --> 00:35:14,344 won't the water be dangerous to drink it? 635 00:35:14,346 --> 00:35:16,146 It doesn't really work quite like that. 636 00:35:16,148 --> 00:35:19,616 You're just taking one high-speed subatomic particle 637 00:35:19,618 --> 00:35:21,351 and changing it into another one 638 00:35:21,353 --> 00:35:22,986 as it gets captured by the water. 639 00:35:22,988 --> 00:35:24,821 Water's still gonna be safe to drink, fortunately. 640 00:35:27,025 --> 00:35:30,594 Narrator: But even if nasa can shield its astronauts from radiation... 641 00:35:32,731 --> 00:35:36,399 ...Space causes other health issues. 642 00:35:36,401 --> 00:35:39,736 Your bones are starting to demineralize. 643 00:35:39,738 --> 00:35:41,071 They're getting weak. 644 00:35:41,073 --> 00:35:44,474 You're getting arthritis even in the prime of your life. 645 00:35:44,476 --> 00:35:47,043 Narrator: Weightlessness during a 10-month journey 646 00:35:47,045 --> 00:35:49,679 will thin the astronauts' bones. 647 00:35:49,681 --> 00:35:51,615 Muscles will waste away, 648 00:35:51,617 --> 00:35:55,952 making walking on landing difficult. 649 00:35:55,954 --> 00:35:57,087 We've evolved. 650 00:35:57,089 --> 00:36:00,457 We've grown up on a planet with gravity. 651 00:36:00,459 --> 00:36:03,193 And as soon as you're an astronaut in outer space 652 00:36:03,195 --> 00:36:05,195 floating around in weightlessness, 653 00:36:05,197 --> 00:36:06,963 it looks like a lot of fun 654 00:36:06,965 --> 00:36:12,102 but, actually, your body is deteriorating from the inside. 655 00:36:12,104 --> 00:36:16,740 Narrator: Astronauts need assistance to walk when returning to earth. 656 00:36:16,742 --> 00:36:20,010 If nasa's mars crew arrive on the red planet 657 00:36:20,012 --> 00:36:23,513 in a poor physical state, they won't be able to function. 658 00:36:23,515 --> 00:36:25,549 [ indistinct talking ] 659 00:36:29,421 --> 00:36:32,155 intense exercise regimes in space 660 00:36:32,157 --> 00:36:35,959 would help the crew stay fit and healthy. 661 00:36:35,961 --> 00:36:37,360 But we're in the dark 662 00:36:37,362 --> 00:36:40,697 about the full impact of extended space travel. 663 00:36:44,603 --> 00:36:46,203 On a mission to mars, 664 00:36:46,205 --> 00:36:50,173 bodies will be pushed to the extreme. 665 00:36:50,175 --> 00:36:52,142 To say that sending humans to mars 666 00:36:52,144 --> 00:36:54,611 is a challenge would be an understatement. 667 00:36:54,613 --> 00:36:57,414 We could be ahead of ourselves. 668 00:36:57,416 --> 00:36:59,549 Plait: Eventually we're going to lose people doing this, 669 00:36:59,551 --> 00:37:01,551 and that's something we have to face. 670 00:37:01,553 --> 00:37:04,854 The question is, is it worth it? 671 00:37:04,856 --> 00:37:08,325 Narrator: But there may not be a choice. 672 00:37:08,327 --> 00:37:11,094 We know that, over time, 673 00:37:11,096 --> 00:37:13,330 this planet is not going to be habitable. 674 00:37:13,332 --> 00:37:14,598 So we really should consider 675 00:37:14,600 --> 00:37:17,367 if there are places we can go outside of earth. 676 00:37:29,982 --> 00:37:34,184 ♪ 677 00:37:34,186 --> 00:37:36,019 narrator: Nasa's mission to mars 678 00:37:36,021 --> 00:37:39,189 will be the toughest undertaking in its history. 679 00:37:39,191 --> 00:37:43,059 The launch from earth will be a monumental challenge... 680 00:37:45,197 --> 00:37:49,466 ...The journey to mars filled with danger, 681 00:37:49,468 --> 00:37:52,736 and survival on the red planet will be a test 682 00:37:52,738 --> 00:37:55,505 unlike anything nasa has faced before. 683 00:37:55,507 --> 00:37:58,441 It's easy to make a bullet list 684 00:37:58,443 --> 00:38:00,577 of of why going to mars is hard. 685 00:38:00,579 --> 00:38:02,312 And that's going to be a long list, 686 00:38:02,314 --> 00:38:04,948 and those bullet points are going to be scary. 687 00:38:04,950 --> 00:38:08,385 A lot of these are serious problems. 688 00:38:08,387 --> 00:38:12,122 Narrator: Nasa's mission to mars needs to be a success. 689 00:38:14,526 --> 00:38:17,127 Earth is in danger 690 00:38:17,129 --> 00:38:20,263 from climate change 691 00:38:20,265 --> 00:38:22,198 to asteroid strikes 692 00:38:22,200 --> 00:38:23,933 to nuclear destruction. 693 00:38:26,371 --> 00:38:28,972 We need an escape plan. 694 00:38:28,974 --> 00:38:31,408 Radebaugh: Earth may just need a lifeboat in the future. 695 00:38:31,410 --> 00:38:34,077 We are growing very quickly, 696 00:38:34,079 --> 00:38:37,347 and we're using a lot of our resources. 697 00:38:37,349 --> 00:38:39,482 We're changing the planet. 698 00:38:39,484 --> 00:38:41,685 Walsh: We're looking for a lifeboat. 699 00:38:41,687 --> 00:38:45,388 Maybe mars is the closest, best chance we've got. 700 00:38:47,426 --> 00:38:48,825 Narrator: Despite the challenges, 701 00:38:48,827 --> 00:38:52,729 nasa's goal is to send the orion spacecraft to mars 702 00:38:52,731 --> 00:38:54,064 in the 2030s. 703 00:38:56,234 --> 00:38:59,703 But to do that, we need a rehearsal. 704 00:38:59,705 --> 00:39:01,371 Durda: I'd love to see us go to mars. 705 00:39:01,373 --> 00:39:02,772 I would love to go myself. 706 00:39:02,774 --> 00:39:04,507 But it might be nice to have a little bit of practice 707 00:39:04,509 --> 00:39:06,176 before we try it. 708 00:39:09,581 --> 00:39:14,351 Narrator: Where better to practice than a destination closer to home. 709 00:39:14,353 --> 00:39:19,222 The ultimate aim is to get humans to mars, and one approach 710 00:39:19,224 --> 00:39:23,259 is to first have a goal of getting humans back to the moon. 711 00:39:23,261 --> 00:39:27,163 Narrator: Orion will first make the shorter trip to the moon. 712 00:39:29,501 --> 00:39:32,769 Lanza: There are a lot of advantages to using the moon. 713 00:39:32,771 --> 00:39:35,872 We can test out different scenarios for operations 714 00:39:35,874 --> 00:39:38,274 we can also test out technologies 715 00:39:38,276 --> 00:39:42,579 much more close to home, and so if something were to go awry, 716 00:39:42,581 --> 00:39:44,214 we can much more easily intervene. 717 00:39:44,216 --> 00:39:45,515 It's a little bit safer. 718 00:39:45,517 --> 00:39:47,217 If we send people to mars, 719 00:39:47,219 --> 00:39:48,985 you know, it's going to be a lot harder for us 720 00:39:48,987 --> 00:39:50,820 to help them if they need it. 721 00:39:55,260 --> 00:39:57,560 Narrator: Nasa's orion moon missions will be far more 722 00:39:57,562 --> 00:39:59,763 than just a training exercise. 723 00:40:01,867 --> 00:40:06,136 They'll use them to build a lunar outpost called gateway, 724 00:40:06,138 --> 00:40:10,407 a space station in orbit around the moon. 725 00:40:10,409 --> 00:40:12,308 It's actually a lot easier to do that 726 00:40:12,310 --> 00:40:13,710 than trying to build something on earth 727 00:40:13,712 --> 00:40:16,646 and get it out of earth orbit. 728 00:40:16,648 --> 00:40:20,517 Narrator: Six planned missions will build and maintain 729 00:40:20,519 --> 00:40:24,621 a space station in orbit around the moon. 730 00:40:24,623 --> 00:40:27,223 It will be a proving ground for the technology 731 00:40:27,225 --> 00:40:31,394 and the science that will help us get to the red planet. 732 00:40:31,396 --> 00:40:34,397 And once nasa has ironed out any problems, 733 00:40:34,399 --> 00:40:37,901 the real mission can begin. 734 00:40:37,903 --> 00:40:41,871 Gateway won't simply be a small step for man. 735 00:40:41,873 --> 00:40:46,109 It'll be a springboard to another planet. 736 00:40:46,111 --> 00:40:49,112 When we first sent humans to another planetary body, 737 00:40:49,114 --> 00:40:52,182 it was the moon, and we had never done that before. 738 00:40:52,184 --> 00:40:54,350 So now we've got the moon under our belt. 739 00:40:54,352 --> 00:40:57,887 We know something about how to send people to another planet. 740 00:40:57,889 --> 00:41:01,357 We don't yet have all the technologies that we might need 741 00:41:01,359 --> 00:41:04,327 to send humans to mars, but we're well on our way. 742 00:41:06,364 --> 00:41:09,632 Narrator: As nasa begins its journey to the red planet, 743 00:41:09,634 --> 00:41:11,601 not everyone is on board. 744 00:41:13,605 --> 00:41:15,805 A lot of people think of mars as our lifeboat 745 00:41:15,807 --> 00:41:17,974 just in case we screw things up on earth, 746 00:41:17,976 --> 00:41:21,244 but we really need to take care of our own planet. 747 00:41:21,246 --> 00:41:24,113 If you want to go there and explore 748 00:41:24,115 --> 00:41:26,516 or build a base, more power to you. 749 00:41:26,518 --> 00:41:27,984 But I'm going to stay 750 00:41:27,986 --> 00:41:30,854 where it's a little bit more green and blue. 751 00:41:30,856 --> 00:41:36,226 ♪ 752 00:41:36,228 --> 00:41:39,729 narrator: Even so, nasa is already building rockets 753 00:41:39,731 --> 00:41:41,798 and testing the technology. 754 00:41:41,800 --> 00:41:47,770 The stage is set for humankind's greatest adventure. 755 00:41:47,772 --> 00:41:50,940 I think we will send humans to mars. 756 00:41:50,942 --> 00:41:53,610 It's just a really, really, really big problem 757 00:41:53,612 --> 00:41:55,745 that we have to figure out how to solve. 758 00:41:55,747 --> 00:41:58,314 But we're good at solving problems. 759 00:41:58,316 --> 00:42:00,750 Given the human mind and how curious we are 760 00:42:00,752 --> 00:42:03,853 and how much we like to climb the next mountain 761 00:42:03,855 --> 00:42:07,156 and achieve the next challenge, mars is right there. 762 00:42:07,158 --> 00:42:08,558 Radebaugh: There is something in the human psyche 763 00:42:08,560 --> 00:42:11,928 that will send us to mars despite all of the challenges. 764 00:42:11,930 --> 00:42:15,698 And so for sure we will go to mars. 765 00:42:15,700 --> 00:42:17,934 Stricker: Even though it's extremely difficult to go to mars, 766 00:42:17,936 --> 00:42:19,736 the answer is always yes 767 00:42:19,738 --> 00:42:21,704 if somebody asks me if we should go 768 00:42:21,706 --> 00:42:23,840 because that's the ultimate goal.