WEBVTT - TechStuff Tours the Space Shuttle 0:00:00.280 --> 0:00:02.840 Brought to you by the reinvented two thousand twelve camera. 0:00:03.160 --> 0:00:08.880 It's ready. Are you get in touch with technology? With 0:00:09.000 --> 0:00:17.720 tech Stuff from how stuff works dot com. Every Hello again, everyone, 0:00:17.800 --> 0:00:20.040 Welcome to tech stuff. My name is Chris Poulette and 0:00:20.040 --> 0:00:22.200 I am an editor at how stuff works dot com. 0:00:22.200 --> 0:00:24.800 Sitting across from me as always a senior writer, Jonathan 0:00:24.840 --> 0:00:28.080 Strickland by rocket to the Moon, by airplane to the rocket, 0:00:28.200 --> 0:00:30.880 by taxi to the airport, by front door to the taxi, 0:00:31.040 --> 0:00:36.320 by throwing back the blanket hanging down the leg. Okay, 0:00:36.360 --> 0:00:38.800 so we want to start off. This episode was something 0:00:38.800 --> 0:00:41.239 we haven't done in a while, and by that I 0:00:41.240 --> 0:00:49.560 mean some listener mail. This listener mail comes from Megan, 0:00:49.600 --> 0:00:52.519 and Megan says, Hi, guys, I love your podcasts. I 0:00:52.600 --> 0:00:55.160 rely on them as a form of continuing education as 0:00:55.160 --> 0:00:57.280 I work on my own research and writing projects that 0:00:57.320 --> 0:01:00.280 relate to technology. As the data approaches for the launch 0:01:00.320 --> 0:01:02.520 of the final Space Shuttle, I wondered if you would 0:01:02.560 --> 0:01:06.920 consider doing one or a dozen special episodes on space technology. 0:01:07.200 --> 0:01:09.919 One episode just on the Space Shuttle itself would be nice. 0:01:10.080 --> 0:01:12.080 How does it fly? What does it do? How does 0:01:12.120 --> 0:01:14.920 it deliver its payloads? Into space without losing its air pressure. 0:01:15.440 --> 0:01:18.080 And then I snipped a big part of her email 0:01:18.160 --> 0:01:20.760 because it relates to other possible topics we may talk 0:01:20.800 --> 0:01:23.280 about the future. And then I go to thanks and 0:01:23.400 --> 0:01:26.200 keep up the good work, Megan. Yeah. I had to 0:01:26.280 --> 0:01:29.240 keep that last little bit in, but it's good, you know. 0:01:29.319 --> 0:01:33.080 I want to be inclusive. Yes, and Megan did have 0:01:33.200 --> 0:01:35.720 several other suggestions, all of which are wonderful ones, and 0:01:35.720 --> 0:01:37.560 we will probably get to them in the future, but 0:01:37.959 --> 0:01:40.200 we want to concentrate on the Space Shuttle right now. 0:01:40.880 --> 0:01:43.440 Talking about trying to get us to talk about space 0:01:43.480 --> 0:01:46.360 technology is doesn't require a lot of arm twisting, so 0:01:47.000 --> 0:01:50.360 we just have to say, jiminy, yeah, we've already talked 0:01:50.360 --> 0:01:52.680 about some in the past and the older space tech, 0:01:52.800 --> 0:01:56.640 but um, yeah, I think that there are several in 0:01:56.680 --> 0:01:59.560 the future. Let's just say that, yeah. Yeah. And I 0:02:00.120 --> 0:02:03.280 also add that we have a great article on how 0:02:03.360 --> 0:02:05.560 Stuff Works dot Com about the Space Shuttle and it's 0:02:05.600 --> 0:02:10.480 called Brace Yourselves How the Space Shuttle Works. And it's uh, 0:02:10.560 --> 0:02:13.919 it's really really well done. It's a comprehensive, very long, 0:02:14.040 --> 0:02:17.679 very involved article, lots of really great animations and illustrations 0:02:17.680 --> 0:02:21.080 in there. I do highly recommend it um. It's it's 0:02:21.720 --> 0:02:24.120 I would call it one of our classic house stuff 0:02:24.120 --> 0:02:27.600 works articles because it kind of pulls out all the stops. 0:02:27.880 --> 0:02:30.480 So we're gonna kind of talk about the space Shuttle, 0:02:30.520 --> 0:02:32.840 and I thought we'd start with maybe sort of a 0:02:32.840 --> 0:02:37.480 brief overview of the history of the program. So you've 0:02:37.480 --> 0:02:40.919 got NASA, you know, they're they've they've had their successful 0:02:41.680 --> 0:02:46.080 launches of getting astronauts into orbit, getting astronauts all the 0:02:46.080 --> 0:02:49.040 way to the Moon and back safely. They've made some 0:02:49.240 --> 0:02:53.920 phenomenal contributions to science um. In around nineteen seventy two, 0:02:53.960 --> 0:02:58.880 President Nixon announced that what he wanted to see what 0:02:58.880 --> 0:03:01.520 what the next up in the space program was going 0:03:01.560 --> 0:03:06.800 to be, was to create a reusable space uh shuttle 0:03:07.000 --> 0:03:11.840 or Space Transportation System st s UM, so that we 0:03:11.840 --> 0:03:14.519 could actually keep using the same vehicle over and over again. 0:03:14.560 --> 0:03:18.360 Because prior to that point, the vehicles we've been using, 0:03:18.360 --> 0:03:22.160 the capsules we've been using we're all one use, used 0:03:22.200 --> 0:03:25.160 one time, and that was all you could use them for. Well, 0:03:25.160 --> 0:03:27.120 you know that that's one of the benefits. You know, 0:03:27.160 --> 0:03:29.280 they're disposable. You can pick one up anytime you're out 0:03:29.280 --> 0:03:30.880 on the road. Right You're right, you just go to 0:03:30.919 --> 0:03:33.359 your costco and hey, you know if I buy them 0:03:33.360 --> 0:03:35.560 in bulk. No, no, that's not how that worked at all. 0:03:35.640 --> 0:03:39.320 It was incredibly expensive to develop the capsules and you 0:03:39.360 --> 0:03:42.680 could only use them one time. So this was an 0:03:42.720 --> 0:03:45.840 idea of creating a space program that would use the 0:03:45.920 --> 0:03:49.480 same vehicle over and over, but there were some trade 0:03:49.480 --> 0:03:52.120 offs that you had to make for that. One of 0:03:52.160 --> 0:03:55.400 those trade offs was that you couldn't necessarily create a 0:03:55.480 --> 0:03:58.880 vehicle that could go into high orbits or to travel 0:03:58.960 --> 0:04:02.160 to distant locations like the Moon or Mars. You could 0:04:02.160 --> 0:04:05.080 only kind of launch into a lower but um part 0:04:05.080 --> 0:04:08.000 of that was this idea of a space Shuttle design 0:04:08.080 --> 0:04:13.000 that could return by gliding down to the Earth's surface, 0:04:13.040 --> 0:04:16.840 as opposed to you know, plummeting and then uh launching 0:04:16.839 --> 0:04:19.800 out a parachute and then kind of drifting down into 0:04:19.800 --> 0:04:23.120 the ocean for retrieval. So the design meant that they 0:04:23.120 --> 0:04:25.880 had to reconcile the fact that we would not be 0:04:26.000 --> 0:04:28.799 using this same sort of vehicle to go to places 0:04:28.839 --> 0:04:32.920 like the Moon or Mars. So this was a calculated 0:04:32.920 --> 0:04:37.080 decision on NASA's part to kind of change the focus 0:04:37.120 --> 0:04:40.640 of the space program. It was now no longer. Just well, 0:04:40.839 --> 0:04:45.560 it was never just about being the first to the moon, 0:04:45.720 --> 0:04:47.440 but that was a big part of it, right, The 0:04:47.440 --> 0:04:53.360 space race was in part a competition. Yeah, that that's true. 0:04:53.400 --> 0:04:59.480 The UH USSR Soviet Union was, of course. And this 0:04:59.520 --> 0:05:02.520 won't be a surprise to probably anybody who listens to 0:05:02.600 --> 0:05:04.760 this podcast, but yeah, we we've talked about the space 0:05:04.839 --> 0:05:08.279 race before between um, the United States and the USSR, 0:05:08.320 --> 0:05:11.680 And you know, it escalated from the time of sput Nick. 0:05:12.000 --> 0:05:16.000 You know, the the evolved the beeps UM up to 0:05:16.040 --> 0:05:18.320 the point where they decided they wanted to go to 0:05:18.360 --> 0:05:20.080 the Moon and it was a competition to see who 0:05:20.120 --> 0:05:24.120 could go and and set foot on the moon first. Um. 0:05:24.279 --> 0:05:27.320 And you know it went from you know, who can 0:05:27.560 --> 0:05:30.880 orbit the Moon or orbit the Earth first? And then 0:05:31.160 --> 0:05:34.200 you know who can have you know, set foot on 0:05:34.240 --> 0:05:36.960 the moon and then there this this presented greater challenges 0:05:37.000 --> 0:05:39.919 because the science involved. The idea of doing science and 0:05:40.000 --> 0:05:43.680 space UM is very compelling because there are things that 0:05:43.760 --> 0:05:45.960 you can do in outer space that you can't do 0:05:46.800 --> 0:05:49.560 uh and within the Earth's gravity, like lots of flippies. 0:05:50.920 --> 0:05:54.000 Well yeah that too, but yeah, I mean this is 0:05:54.040 --> 0:05:56.960 the the also from what I understand, tang tastes best 0:05:58.000 --> 0:05:59.799 if you're in if you're in a low Earth orbit. 0:06:00.080 --> 0:06:02.920 And yes, contrary to popular myth, tang was not created 0:06:03.000 --> 0:06:05.920 for the Space program. It just happens to be very 0:06:05.920 --> 0:06:09.279 handy in this in this content. But um, but yeah, 0:06:09.320 --> 0:06:11.840 I mean this was, this was we're talking about this 0:06:12.160 --> 0:06:15.960 as the early seventies, fresh on the heels of uh, 0:06:16.000 --> 0:06:19.120 you know, the Apollo program. Yes, um, so this is 0:06:19.160 --> 0:06:22.360 really the next step exactly. And so NASA then awarded 0:06:22.400 --> 0:06:27.040 the prime contract for the Shuttle to Rockwell International, and 0:06:27.880 --> 0:06:30.200 Rockwell International had to come up with different ways of 0:06:30.240 --> 0:06:34.560 creating some reusable materials, including things like the tiles that 0:06:34.600 --> 0:06:38.039 help absorb heat upon re entry. That was a big thing, right, 0:06:38.120 --> 0:06:40.679 you know. It wasn't just that, uh that it needed 0:06:40.680 --> 0:06:43.839 to be able to fly to the surface of the 0:06:43.839 --> 0:06:46.359 Earth safely, but it had to have something that would 0:06:47.040 --> 0:06:50.359 absorb and redistribute heat in a way that would protect 0:06:50.360 --> 0:06:53.360 the people inside and could be used over and over again, 0:06:53.360 --> 0:06:54.880 as opposed to something that could only do it the 0:06:54.920 --> 0:06:57.320 one time. Right, if you if you go see one 0:06:57.320 --> 0:07:00.640 of the capsules from the earlier space missions and say 0:07:00.880 --> 0:07:04.080 the Smithsonian Institution, for example, and you actually look at 0:07:04.080 --> 0:07:07.960 the heat shield on the bottom of the capsule and 0:07:08.000 --> 0:07:12.400 how burned it looks from re entry. It's it creates 0:07:12.400 --> 0:07:14.960 an impression because that's a it's an awful lot of 0:07:14.960 --> 0:07:19.160 friction coming back home. You said the word friction, did, Yeah, 0:07:19.320 --> 0:07:22.600 what's we'll we'll address that when we get into re entry. 0:07:22.920 --> 0:07:26.320 But before you guys right in about friction, just let 0:07:26.480 --> 0:07:28.480 I want to let you know I will address that. 0:07:30.000 --> 0:07:32.560 But you're kinda have to wait. Should we take that? No, No, 0:07:32.720 --> 0:07:34.800 we need to keep that in because it's important. It's 0:07:34.800 --> 0:07:38.560 important because it's it's sort of shorthand right from talking 0:07:38.600 --> 0:07:40.920 about the heat that's generated. But it's a little more 0:07:41.000 --> 0:07:43.520 complicated than that. And don't worry people, we will talk 0:07:43.520 --> 0:07:45.840 about it. We're just gonna talk about that when we 0:07:45.880 --> 0:07:48.200 talk about the shuttle re entering the Earth. Samus here, 0:07:48.680 --> 0:07:53.400 So the the first shuttle that was ever built, you 0:07:53.440 --> 0:07:55.000 know the you know the name of the very first 0:07:55.000 --> 0:07:57.440 shuttle ever built that was not designed to go into space. 0:07:57.560 --> 0:07:59.160 It was just the first one that was built to 0:07:59.200 --> 0:08:02.200 test the flying capability, right, Yes, yes, As a matter 0:08:02.240 --> 0:08:04.840 of fact, I have some history on each of the 0:08:04.880 --> 0:08:08.520 spacecraft involved. Um and I remember this because I actually 0:08:08.600 --> 0:08:11.760 have I still have it a lunchbox with this space 0:08:11.800 --> 0:08:15.440 particular spacecraft on it. What was from one from my 0:08:15.720 --> 0:08:19.440 younger days. Um, and that would be the Enterprise OV 0:08:19.680 --> 0:08:23.360 one oh one. Yes, this is a and And you 0:08:23.400 --> 0:08:27.200 may wonder is this in reference to the the long 0:08:27.600 --> 0:08:33.360 loved science fiction series Star Trek. Yes, it is the 0:08:33.400 --> 0:08:35.840 inner the Shuttle Enterprise, which was not designed to go 0:08:35.840 --> 0:08:39.480 into space. It was only to test the the gliding 0:08:39.559 --> 0:08:43.640 and flying capabilities of the Shuttle to UH, to see 0:08:43.720 --> 0:08:47.440 make sure that the design actually worked. Um, that's all 0:08:47.480 --> 0:08:50.080 it did. So they launched it from a Boeing seven 0:08:50.160 --> 0:08:55.400 forty seven and it successfully flew and landed safely at 0:08:55.480 --> 0:08:59.600 the Edwards Air Force Space Yes, and it actually rolled out. 0:08:59.760 --> 0:09:01.880 If think about it, we were talking about the early seventies, 0:09:01.920 --> 0:09:04.400 they didn't waste any time. The Enterprise rolled out on 0:09:04.480 --> 0:09:08.640 September seventeenth, nineteen seventy six, So it was it didn't 0:09:08.679 --> 0:09:11.480 take years and years and years to develop. I also 0:09:11.520 --> 0:09:13.079 want to say, is just as an aside. I know 0:09:13.120 --> 0:09:14.920 we've got a lot to cover, but it ended up 0:09:14.960 --> 0:09:18.920 being sort of a recursive thing since the Enterprise space 0:09:18.920 --> 0:09:22.680 Shuttle was mentioned in Star Trek as being the first Enterprise, 0:09:23.520 --> 0:09:28.360 So it's that I find that amusing. So uh, there 0:09:28.400 --> 0:09:31.280 were other the The actual shuttles that were used in 0:09:31.440 --> 0:09:36.480 space uh flights were the Columbia, the Discovery, the Atlantis, 0:09:36.640 --> 0:09:41.080 the Challenger, and then later the Endeavor. Now the Columbia, Discovery, Atlantis, 0:09:41.120 --> 0:09:44.960 and Challenger were the original four shuttles. Yep. The Columbia 0:09:45.000 --> 0:09:47.760 was rolled out in seventy nine, Challenger in eighty two, 0:09:47.800 --> 0:09:51.160 Discovery in eighty three, Atlantis and eighty five, and Endeavor 0:09:51.160 --> 0:09:54.800 in ninety one. And the very first space Shuttle flight 0:09:55.320 --> 0:09:58.079 as in going into lower thorbit was in nineteen eight one, 0:09:58.120 --> 0:10:02.520 and it was the Columbia. Yes. Uh. Now, again these 0:10:02.559 --> 0:10:05.080 were all designed to go into low Earth or a bit. 0:10:05.200 --> 0:10:07.240 And I thought it might be interesting to kind of 0:10:07.240 --> 0:10:11.200 take sort of a an audio tour of the Shuttle. 0:10:11.240 --> 0:10:12.640 In other words, we're just going to kind of talk 0:10:12.679 --> 0:10:15.360 about the different parts of the Space Shuttle. And and 0:10:15.520 --> 0:10:19.120 this is um I kind of took it from pre launch, 0:10:19.960 --> 0:10:23.760 So this is the the whole kit and caboodle. One 0:10:23.880 --> 0:10:25.840 might say, it's not just the orbiter. And now that's 0:10:25.840 --> 0:10:27.480 what most of us think about when we think about 0:10:27.480 --> 0:10:29.800 the Space Shuttle. You think of the orbiter, which is 0:10:29.840 --> 0:10:32.280 the one that looks kind of like a funky airplane. 0:10:32.840 --> 0:10:35.319 But the the if you're talking about the whole Space Shuttle, 0:10:35.320 --> 0:10:40.000 you're talking about three major sections. Your solid rocket fuel boosters, 0:10:40.640 --> 0:10:43.319 which do the lion share of the work when you're 0:10:43.320 --> 0:10:46.640 talking about launch, they do. They provide seventy of the 0:10:46.679 --> 0:10:51.400 thrust that's needed to lift off the launch pad. So 0:10:51.440 --> 0:10:55.000 you're thinking, like, well, if the solid rocket fuel boosters 0:10:55.040 --> 0:10:59.520 are doing sev of the work, where's the other coming from. 0:10:59.760 --> 0:11:02.839 That's actually coming from the orbiter's engines. But we'll get 0:11:02.880 --> 0:11:07.400 into that. So the solid rocket fuel boosters are using 0:11:07.520 --> 0:11:09.840 a They use a solid rocket motor. It has a 0:11:09.880 --> 0:11:13.680 propellant that's uh uh. It's also got an igniter and 0:11:13.720 --> 0:11:16.400 a nozzle, so the nozzle courses where it directs the 0:11:16.440 --> 0:11:21.400 gases out so that it creates thrust. The fuel it 0:11:21.600 --> 0:11:24.440 uses is it consists of. While the fuel part is 0:11:24.440 --> 0:11:29.719 the atomized aluminum has oxidizers in the form of ammonium percolate. 0:11:30.240 --> 0:11:32.959 It's got a catalyst the form of iron oxide powder. 0:11:33.000 --> 0:11:36.280 It's got a binder agent which I don't even think 0:11:36.320 --> 0:11:38.920 I could even pronounce, and then there's a curing agent 0:11:39.080 --> 0:11:43.360 which is an epoxy resin, and this material altogether makes 0:11:43.360 --> 0:11:48.080 a solid rocket fuel. And this stuff weighs a lot, 0:11:48.360 --> 0:11:50.920 and you know that it's one of the one of 0:11:50.960 --> 0:11:53.360 the big challenges with space flight is the fact that 0:11:53.440 --> 0:11:57.000 your fuel weighs so much. Um. In order to to 0:11:57.080 --> 0:12:00.520 launch something of a particular mass into space, you need 0:12:00.559 --> 0:12:02.040 a lot of fuel to get there. Well, the more 0:12:02.080 --> 0:12:04.000 fuel you add, the more weight you add, so you 0:12:04.000 --> 0:12:05.800 you have this problem where you've got to get the 0:12:05.920 --> 0:12:09.720 right ratio of fuel to counteract not just the weight 0:12:09.760 --> 0:12:12.240 of the vehicle, but the weight of the fuel as well. 0:12:13.120 --> 0:12:16.400 According to NASA, the Space Shuttle, if you wanted to 0:12:16.640 --> 0:12:18.720 put it on a scale, you need a pretty big scale. 0:12:18.840 --> 0:12:22.920 It weighs more than two point zero four million kilograms 0:12:23.080 --> 0:12:26.800 or four and a half million pounds at launch, and 0:12:26.960 --> 0:12:29.720 uh it uses in in eight and a half minutes 0:12:30.280 --> 0:12:33.600 after launch. It uses more than one point five nine 0:12:33.679 --> 0:12:37.439 million kilograms or three point five million pounds of propellant. Yeah, 0:12:37.440 --> 0:12:43.240 it's slightly less fuel efficient than a hummer. Yes, but 0:12:43.320 --> 0:12:47.680 hummer doesn't use solid fuel. No, no, no, But I 0:12:47.720 --> 0:12:50.559 wanted to mention something else that this this solid rocket 0:12:50.600 --> 0:12:54.200 fuel booster, it's actually jointed it's not it's not one 0:12:54.280 --> 0:12:56.040 solid piece. And if you were to ever actually take 0:12:56.040 --> 0:12:57.800 a look at one of these and just see the 0:12:57.840 --> 0:13:00.920 scale of it, how huge it is, you would understand 0:13:00.920 --> 0:13:03.640 there's no building in of one piece. Would not be 0:13:03.840 --> 0:13:09.880 it would not be a practical Well, they use O rings, 0:13:10.000 --> 0:13:12.720 rubber O rings seals to seal the two sections or 0:13:12.760 --> 0:13:16.120 the multiple sections together. Right, Basically, they're they're sort of 0:13:16.160 --> 0:13:20.280 like gaskets. Yes, so these are meant to create uh 0:13:20.280 --> 0:13:25.040 an airtight seal around the solid rocket boosters. Well, it 0:13:25.120 --> 0:13:27.640 was it was one of these O rings that caused 0:13:27.640 --> 0:13:30.800 the problem that led to the Challenger disasters. We wanted 0:13:30.840 --> 0:13:32.760 to talk a little bit about the disasters that have 0:13:32.760 --> 0:13:35.800 happened in the Space Shuttle program. Well, the Challenger disaster 0:13:35.880 --> 0:13:38.320 was a very famous one. And what happened was that 0:13:38.400 --> 0:13:41.800 when the day of that launch it was unusually cold. 0:13:42.280 --> 0:13:45.680 The cold weather had made the the rubber O rings 0:13:45.760 --> 0:13:48.199 shrink a little bit, so they were no longer properly 0:13:48.360 --> 0:13:52.439 sealing the joints. But in the solid rocket booster upon launch, 0:13:52.520 --> 0:13:55.760 some of the hot gases, I mean we're talking incredibly 0:13:55.840 --> 0:13:57.959 hot gases from the that were being emitted by the 0:13:58.000 --> 0:14:01.280 solid rocket booster were escaping through the joints because the 0:14:01.320 --> 0:14:04.520 O rings were no longer sealing them properly. Some of 0:14:04.520 --> 0:14:08.040 these cut through like a blowtorch. They cut through the 0:14:08.080 --> 0:14:11.160 exterior of the external fuel tank, which is the next 0:14:11.160 --> 0:14:13.719 section we'll be talking about in a second. And the 0:14:13.760 --> 0:14:16.240 external fuel tank has two different kinds of fuel in it, 0:14:16.280 --> 0:14:20.080 as liquid oxygen and liquid hydrogen. Well, the hot gases 0:14:20.280 --> 0:14:23.960 from the solid rocket booster ended up igniting the liquid 0:14:24.040 --> 0:14:28.800 hydrogen inside the external fuel tank, which then promptly exploded. 0:14:28.880 --> 0:14:31.720 That was what caused the explosion on the Challenger flight. 0:14:32.160 --> 0:14:36.840 So it was after that the spatial program actually stopped 0:14:36.880 --> 0:14:39.920 for a few years after the Challenger disaster while NASA 0:14:40.200 --> 0:14:43.280 was investigating the disaster and trying to determine what was 0:14:43.360 --> 0:14:48.080 the cause and how would the organization prevents such a 0:14:48.120 --> 0:14:52.760 thing from happening in the future. So ultimately you could 0:14:52.840 --> 0:14:55.640 say that the rubber O rings in the the solid 0:14:55.720 --> 0:14:59.600 rocket fuel booster was they were to blame for at 0:14:59.680 --> 0:15:02.640 least that part of the Challenger to that disaster, the 0:15:03.120 --> 0:15:09.880 whole initial um emergency that then lead to the tragedy. Yeah, 0:15:09.920 --> 0:15:13.840 and it it those engines do get hot. They according 0:15:13.880 --> 0:15:17.440 again according to NASA. The temperatures inside the engines themselves 0:15:18.560 --> 0:15:23.720 reach more than six thousand degrees fahrenheit around three three thousand, 0:15:23.200 --> 0:15:28.320 three fifteen point six degrees celsius. Yeah, so that's you know, 0:15:29.840 --> 0:15:33.280 any any leak, it can be very catastrophic in a 0:15:33.400 --> 0:15:35.640 very very short span of time, as we have seen. Right. 0:15:36.240 --> 0:15:39.160 So that's our first section that we wanted to talk about. Next, 0:15:39.200 --> 0:15:41.280 we have the external fuel tank. Now, this is the 0:15:42.120 --> 0:15:45.560 big kind of rocket looking thing that sticks to the 0:15:45.640 --> 0:15:49.600 shuttle even after they they jettison the rocket boosters. By 0:15:49.600 --> 0:15:51.520 the way, in order to jettison these things, they have 0:15:51.560 --> 0:15:56.680 these explosive charges between the sections that that when they explode, 0:15:57.000 --> 0:16:01.600 they break the the the links between one element in 0:16:01.600 --> 0:16:03.560 the next, which, of course that means that you have 0:16:03.640 --> 0:16:05.240 to also be very careful with that because I mean, 0:16:05.280 --> 0:16:07.840 anytime you're using explosives near a whole lot of fuel, 0:16:07.960 --> 0:16:10.720 clearly you've got to take a lot of precautions. Well, 0:16:10.800 --> 0:16:14.200 external fuel tank stores liquid hydrogen liquid oxygen, as I said, 0:16:15.000 --> 0:16:21.000 and that's what provides fuel to the orbiters three main engines. Uh, 0:16:21.040 --> 0:16:23.640 and it's uh, there's there's a six to one ratio 0:16:24.000 --> 0:16:27.040 for liquid hydrogen to liquid oxygen so there's far more 0:16:27.080 --> 0:16:31.960 liquid hydrogen on than the than oxygen. The external fuel 0:16:31.960 --> 0:16:34.080 tank is a hundred fifty eight feet long, which about 0:16:34.120 --> 0:16:36.640 forty eight ms, and it's got a diameter of twenty 0:16:36.640 --> 0:16:39.960 seven point six ft or about eight point four meters, 0:16:40.000 --> 0:16:44.920 And when it's empty, it weighs a feather light seventy 0:16:44.920 --> 0:16:50.760 eight thousand pounds or thirty five thousand four UM, and 0:16:50.800 --> 0:16:55.120 it holds one point six million pounds of propellant, which 0:16:55.120 --> 0:16:59.160 again seven nineteen thous so it's got a total volume 0:16:59.200 --> 0:17:03.640 of around five and twenty six thousand gallons or two 0:17:03.640 --> 0:17:07.360 million liters. So yeah, it holds. It holds a lot 0:17:07.400 --> 0:17:10.720 of fuel UM and it's it's made out of aluminium 0:17:10.760 --> 0:17:14.520 and aluminium composite materials. It's got the two tanks. The 0:17:14.560 --> 0:17:17.080 forward tank is the one for the oxygen, the aft 0:17:17.200 --> 0:17:21.280 tank is for hydrogen, and then there's an inner tank 0:17:21.359 --> 0:17:26.320 region that separates the two from each other. So this 0:17:26.320 --> 0:17:30.240 this UH propellant, it flows, It flows through a um 0:17:30.600 --> 0:17:35.960 seventeen in diameter feed linet cimeters. I always have to 0:17:35.960 --> 0:17:37.600 try and do that because I keep forgetting that we 0:17:37.640 --> 0:17:39.360 have so many people from around the world who listen 0:17:39.400 --> 0:17:42.879 to our podcast and we're used to using these outmoded 0:17:43.320 --> 0:17:46.159 methods of measurement, and everyone else is much more forward 0:17:46.160 --> 0:17:50.040 thinking than we are. Then we uh So the fuel 0:17:50.080 --> 0:17:53.520 flows through this this diameter or the diameter this feed 0:17:53.520 --> 0:17:57.680 line and goes to the shuttle's main engines and then 0:17:57.800 --> 0:18:00.200 the oxygen. By the way, if you if you want 0:18:00.240 --> 0:18:04.160 to know how fast the the the fuel flows through 0:18:04.160 --> 0:18:07.240 this line. The auction flows through at a rate of 0:18:07.280 --> 0:18:11.439 around seventeen thousand, six hundred gallons per minute, which is 0:18:11.600 --> 0:18:15.320 sixty six thousand, six hundred liters per minute. Strangely enough, 0:18:15.320 --> 0:18:18.800 we still use minutes in both systems of measurement. Uh. 0:18:18.880 --> 0:18:22.640 Then hydrogen, though, flows at forty seven thousand, four hundred 0:18:22.720 --> 0:18:25.600 gallons per minute, or a hundred seventy nine thousand liters 0:18:25.600 --> 0:18:30.760 per minute, so quite fast indeed. Yeah, well, I mean seriously, 0:18:30.880 --> 0:18:34.080 you could if you were using water instead of fuel, 0:18:34.119 --> 0:18:37.720 the shuttles engines could drain a regular size swimming pool 0:18:38.160 --> 0:18:42.199 uh in about seconds. Yeah, which, and if you were 0:18:42.280 --> 0:18:44.200 using water instead of fuel, that would be the most 0:18:44.240 --> 0:18:48.520 awesome water park ever, although you could probably only go once. 0:18:48.920 --> 0:18:52.040 So the the fuel, they burn the fuel in the 0:18:52.080 --> 0:18:56.960 prechamber to create high pressure and then the heat and 0:18:57.000 --> 0:19:01.239 the pressure from the gases drive turbopump, and then the 0:19:01.240 --> 0:19:06.119 fuels burned in the main combustion chamber. They direct the 0:19:06.240 --> 0:19:08.840 gases out of the nozzle at around six thousand miles 0:19:08.840 --> 0:19:12.560 per hour ten thousand kilometers per hour, and that means 0:19:12.560 --> 0:19:17.600 that each of the three engines can generate around three 0:19:18.520 --> 0:19:23.359 thousand to four seventy thousand pounds of thrust. Uh. And 0:19:24.480 --> 0:19:28.399 so that's you know, that's what's providing that other of 0:19:28.520 --> 0:19:32.640 thrust when the Shuttle is going to launch. Um. Now, 0:19:32.720 --> 0:19:38.040 the the external tank is covered with a spray on 0:19:38.359 --> 0:19:42.680 foam installation, which leads us to a discussion, a brief 0:19:42.680 --> 0:19:48.640 discussion about the second Space Shuttle disaster, and uh, this 0:19:48.720 --> 0:19:51.439 is the Columbia disaster. Now, you may remember when the 0:19:51.440 --> 0:19:54.399 Columbia was coming in in two thousand three, when it 0:19:54.440 --> 0:19:57.200 was coming up for the descent towards Earth, it broke 0:19:57.240 --> 0:20:03.040 apart on re entry. Well, the investigation led to the 0:20:03.080 --> 0:20:07.199 discovery that that the likely cause of that was that 0:20:07.359 --> 0:20:10.840 a piece of this foam installation broke off of the 0:20:10.880 --> 0:20:15.960 external tank during launch and struck the orbiter and that's 0:20:16.000 --> 0:20:19.160 what weakened the orbiter and caused it to break apart 0:20:19.240 --> 0:20:22.360 upon re entry. And one of the most controversial things 0:20:22.400 --> 0:20:26.080 about the the orbiter itself has been the heat resistant tiles. 0:20:26.680 --> 0:20:28.520 I mean even from the very beginning. I remember those 0:20:28.520 --> 0:20:31.639 discussions when I was a kid, and um, you know 0:20:31.760 --> 0:20:36.160 those they're they're made of a type of foam, uh basically, 0:20:36.240 --> 0:20:38.399 and and they're they're delicate. I mean, even on the 0:20:38.480 --> 0:20:40.920 very first missions they would notice that some of them 0:20:40.960 --> 0:20:44.160 would fall out. Um. And they've done a lot of 0:20:44.680 --> 0:20:46.320 you know, made made a lot of changes to the 0:20:46.359 --> 0:20:51.200 tiles over the years, but um, they are still all 0:20:51.240 --> 0:20:53.480 things considered, even though they are very heat resistant, I 0:20:53.480 --> 0:20:57.600 mean we're talking thousands and thousands of degrees and um, 0:20:57.640 --> 0:21:01.959 because they do on re entry hit about three thousand 0:21:01.960 --> 0:21:07.199 degrees fahrenheit actually comes back into the atmosphere forty eight 0:21:07.240 --> 0:21:10.520 degrees celsius. So I mean, even though they are amazingly 0:21:10.520 --> 0:21:13.000 heat resistant, they are remarkably fragile for all of that. 0:21:13.080 --> 0:21:15.639 So they have to be very careful, um with that. 0:21:15.680 --> 0:21:20.720 And now they on on flights subsequent to Columbia's um accident, 0:21:21.000 --> 0:21:23.639 they have been very careful to check the outside of 0:21:23.640 --> 0:21:26.840 the spacecraft before re entry. Yeah, and there have been 0:21:27.200 --> 0:21:31.200 spatial launch delays when they've discovered even the smallest of 0:21:31.200 --> 0:21:33.879 of flaws which you know, as far as we know, 0:21:33.960 --> 0:21:37.199 could have potentially have saved the lives of other astronauts. Yes, 0:21:37.560 --> 0:21:41.120 it's of course it's impossible to know, you know which 0:21:41.119 --> 0:21:43.960 ones would have successfully landed and which ones wouldn't. But 0:21:44.200 --> 0:21:46.840 it's much better to know that they've they've gone through 0:21:46.880 --> 0:21:50.959 these sort of procedures in order to maintain astronauts safety. 0:21:51.760 --> 0:21:57.080 I mean, these these accidents were tragic and multiple ways. Uh. 0:21:57.240 --> 0:22:00.240 First of all, and in my opinion, most importantly meant 0:22:00.280 --> 0:22:03.480 the loss of lives, and and that is truly a 0:22:03.520 --> 0:22:08.440 tragic thing. Uh. It also in a more superficial way, really, 0:22:08.480 --> 0:22:11.760 when you look at the big picture, men a setback 0:22:11.840 --> 0:22:15.760 in the space program um, which you know that's a 0:22:15.840 --> 0:22:18.240 problem as well, and we've had a lot of advances 0:22:18.280 --> 0:22:23.880 in technology due to the Space program. So I admire 0:22:24.040 --> 0:22:27.440 the fact that NASA has taken these incredible precautions, which 0:22:28.040 --> 0:22:30.960 when you're excited about a launch and you've planned a 0:22:31.040 --> 0:22:34.360 trip down to Florida to watch a launch, UH, can 0:22:34.400 --> 0:22:36.720 be frustrating, you know, you go down there and then 0:22:37.080 --> 0:22:40.400 the launch is delayed because of this. But it's that's 0:22:40.480 --> 0:22:44.160 much better than the alternative obviously. So now we're moving 0:22:44.200 --> 0:22:47.080 on to the orbiter. We talked about the solid fuel 0:22:47.160 --> 0:22:50.440 rocket boosters and the external tank. The orbiter is next. 0:22:51.160 --> 0:22:52.880 So the orbiters, of course what we think of when 0:22:52.880 --> 0:22:55.119 we when we talk about the space Shuttle. That's the 0:22:55.800 --> 0:23:00.440 very iconic shuttle. UM it has a like I said, 0:23:00.480 --> 0:23:04.240 three main engines, it's got an orbital maneuvering system. It is. 0:23:04.560 --> 0:23:06.840 Each of the orbiter engines, by the way, as fourteen 0:23:06.880 --> 0:23:09.879 ft long or four point three meters and seven and 0:23:09.920 --> 0:23:12.240 a half feet in diameter or two point three meters, 0:23:12.800 --> 0:23:16.280 and each engine weighs six thousand, seven hundred pounds or 0:23:16.359 --> 0:23:23.040 around three thousand and they are it's hard to get 0:23:23.040 --> 0:23:25.600