WEBVTT - The Apollo Missions 0:00:04.120 --> 0:00:07.160 Get in touch with technology with tech Stuff from how 0:00:07.200 --> 0:00:13.760 stuff works dot com. Hey there, and welcome to tech Stuff. 0:00:13.800 --> 0:00:16.960 I'm your host, Jonathan Strickland. I'm an executive producer over 0:00:17.000 --> 0:00:20.040 at how Stuff Works in a love all things tech, 0:00:20.600 --> 0:00:23.640 and in our last couple of episodes, I looked at 0:00:23.680 --> 0:00:27.400 the earliest spacecraft used by the Soviet Union and the 0:00:27.480 --> 0:00:31.000 United States during the Space Race. I talked about the 0:00:31.040 --> 0:00:34.840 first people in space, the first spacewalk, and the development 0:00:34.880 --> 0:00:38.560 of spacecraft like the Gemini or Jiminy if you prefer, 0:00:39.040 --> 0:00:41.680 which could hold more than one astronaut at a time. 0:00:41.880 --> 0:00:45.360 We're going to continue today by looking to the successor 0:00:45.560 --> 0:00:48.919 to the Gemini program, that would be the Apollo program. 0:00:48.960 --> 0:00:50.480 But before I can do that, I'm going to talk 0:00:50.479 --> 0:00:53.519 a little bit more about Gemini because there's some points 0:00:53.560 --> 0:00:55.440 that I kind of covered at the end of the 0:00:55.520 --> 0:00:57.640 last episode, but I feel we need to go into 0:00:57.640 --> 0:01:01.000 more detailed to understand why they were so warnant. In 0:01:01.040 --> 0:01:04.000 the next episode, I will actually finish up about the 0:01:04.040 --> 0:01:07.200 Apollo program because it turns out a lot happened during that, 0:01:07.600 --> 0:01:09.920 and then we're going to transition to talk about the 0:01:10.080 --> 0:01:14.760 Soyuz spacecraft that would be the Russian successor in the 0:01:14.840 --> 0:01:18.600 Soviet program, and it's a spacecraft that is still being 0:01:18.680 --> 0:01:22.480 used today decades later. So we'll get into that in 0:01:22.520 --> 0:01:25.880 the next episode. Now, part of the reason I had 0:01:25.959 --> 0:01:29.200 to cover the whole space race in this way and 0:01:29.200 --> 0:01:32.240 this kind of jumping around way, is that these various 0:01:32.280 --> 0:01:37.039 projects were not all linear. It's not like Mercury was planned, 0:01:37.200 --> 0:01:40.920 started and ended, and then Jim and I began, and 0:01:40.959 --> 0:01:44.200 then Jim and I went through and ended, and then 0:01:44.200 --> 0:01:48.320 Apollo began. In fact, technically the Apollo mission began before 0:01:48.520 --> 0:01:50.920 GEM and I did. GEM and I ended up being 0:01:50.960 --> 0:01:55.160 necessary in order to test certain technologies and procedures and 0:01:55.240 --> 0:01:58.760 processes that would make Apollo possible. It was a a 0:01:58.880 --> 0:02:03.920 bridge between en Mercury and Apollo. It was decided after 0:02:03.960 --> 0:02:06.400 the fact that we had made this commitment that we 0:02:06.400 --> 0:02:09.359 were going to send astronauts to the Moon now. Project 0:02:09.400 --> 0:02:12.840 Mercury's research and development phase started back in nineteen fifty eight, 0:02:13.040 --> 0:02:16.480 and the operational phase didn't begin until nineteen sixty one, 0:02:16.560 --> 0:02:20.359 and the project essentially concluded in nineteen sixty three. Before 0:02:20.400 --> 0:02:24.240 the first Mercury spacecraft had even launched, NASA was already 0:02:24.320 --> 0:02:27.640 talking about what it would take to design, build, and 0:02:27.760 --> 0:02:31.720 launch spacecraft capable of holding three astronauts and sending them 0:02:31.720 --> 0:02:35.680 to the Moon and bringing them back. This hypothetical craft 0:02:35.720 --> 0:02:38.520 would need to be able to do lots of different stuff, 0:02:39.040 --> 0:02:44.200 and it would become the Apollo program. That enormous leap 0:02:45.000 --> 0:02:49.880 would be a huge, huge jump off of the Mercury spacecraft. 0:02:49.919 --> 0:02:53.600 Remember that was a one astronauts spacecraft. It was really 0:02:53.639 --> 0:02:57.960 just designed for orbital flights around the Earth, and it 0:02:58.000 --> 0:03:02.840 was largely a testing ground for technologies and also just 0:03:02.919 --> 0:03:05.720 to to see what we could learn based upon that 0:03:05.880 --> 0:03:09.120 sort of limited use of space travel to go around 0:03:09.160 --> 0:03:12.160 the Earth. Not like that wasn't a difficult enough thing 0:03:12.240 --> 0:03:17.079 to do already, but it was still a small step 0:03:17.160 --> 0:03:21.080 toward what people had eventually planned for the United States 0:03:21.160 --> 0:03:25.000 space program. So the Mercury was a phenomenal achievement. I 0:03:25.040 --> 0:03:28.240 don't want to downplay that. It was amazing that we 0:03:28.280 --> 0:03:31.520 could build a spacecraft that could withstand the rigors of space, 0:03:32.240 --> 0:03:35.640 send someone up there and bring that person back down safely. 0:03:35.800 --> 0:03:38.280 And also there was no need for the astronaut to 0:03:38.360 --> 0:03:43.360 eject from the Mercury capsule. Remember the Soviet cosmonauts on 0:03:43.480 --> 0:03:47.040 the Vostok spacecraft in the Soviet program, they had to 0:03:47.080 --> 0:03:51.040 eject on re entry. They could not just ride the 0:03:51.120 --> 0:03:53.880 vast stalk down to the surface. They would have probably 0:03:53.920 --> 0:03:57.120 been rattled to death if they had done that. But 0:03:57.160 --> 0:04:00.320 the mercury was also extremely limited right it had at 0:04:00.560 --> 0:04:04.520 orbital limitation. It wasn't meant to do anything beyond orbit 0:04:04.560 --> 0:04:06.880 the Earth, and it lacked the capabilities to do the 0:04:06.920 --> 0:04:09.320 stuff the Apollo spacecraft would have to do in order 0:04:09.320 --> 0:04:12.360 to have a successful mission. So that's why the Gemini 0:04:12.400 --> 0:04:15.960 program would slip in between the two. And it also 0:04:16.000 --> 0:04:19.000 provided a training ground for astronauts to learn how to 0:04:19.240 --> 0:04:23.080 endure longer space flights, because that was gonna be an issue. 0:04:23.080 --> 0:04:24.280 If you wanted to go all the way to the 0:04:24.320 --> 0:04:26.120 Moon and back, it was going to take several days, 0:04:26.240 --> 0:04:29.800 not just a few hours or maybe one day of orbit. 0:04:30.480 --> 0:04:33.320 They also learned how to conduct spacewalks, how to navigate 0:04:33.360 --> 0:04:37.000 and pilot a spacecraft in space. That was a big deal, 0:04:37.440 --> 0:04:40.720 and also they needed to learn how to rendezvous and 0:04:40.800 --> 0:04:44.160 doc with other spacecraft. Now I mentioned in the previous 0:04:44.240 --> 0:04:48.160 episode that the first mission to have two spacecraft dock 0:04:48.320 --> 0:04:52.080 in orbit was in a Gemini mission. It was Gemini eight, 0:04:52.440 --> 0:04:56.200 which was piloted by Neil Armstrong and David Scott, and 0:04:56.240 --> 0:04:58.960 I also mentioned that there was an emergency in that 0:04:59.040 --> 0:05:03.680 particular mission and where after the two spacecraft had docked 0:05:03.680 --> 0:05:05.200 there was a problem. But I wanted to talk a 0:05:05.240 --> 0:05:08.719 little bit more about the actual docking process, just to 0:05:08.760 --> 0:05:13.160 kind of give across how complicated this is and how 0:05:13.240 --> 0:05:17.320 much precision is required to make it work. So the 0:05:17.360 --> 0:05:21.320 Gemini spacecraft docked with a vehicle that existed only for 0:05:21.360 --> 0:05:24.640 the purpose of testing the docking technology and the procedures. 0:05:24.960 --> 0:05:28.800 It was called an a Gina Target vehicle, and the 0:05:28.880 --> 0:05:33.880 official designation was g A t V five zero zero 0:05:34.080 --> 0:05:39.200 three for for the Gemini eight. This spacecraft was seven 0:05:39.240 --> 0:05:42.560 point nine three ms long that's about twenty six ft, 0:05:42.800 --> 0:05:45.400 and had a diameter of one point five two ms 0:05:45.520 --> 0:05:48.640 or just a hair under five feet in diameter, and 0:05:48.760 --> 0:05:52.320 had its own flight control electronics at its own guidance systems, 0:05:52.440 --> 0:05:56.640 propulsion system, electrical power. All of this was necessary so 0:05:56.720 --> 0:05:58.960 NASA can make certain the spacecraft was in the proper 0:05:59.080 --> 0:06:03.560 orbit and orientation for a rendezvous and docking mission. On 0:06:03.560 --> 0:06:07.400 one end of this target vehicle there was a cone 0:06:07.440 --> 0:06:11.159 shaped section, so this was the part where the Gemini 0:06:11.240 --> 0:06:15.679 spacecraft would dock into. It's kind of a a cone 0:06:15.760 --> 0:06:19.839 area and it conformed to the shape of the nose 0:06:20.200 --> 0:06:24.000 of the Gemini spacecraft. So you bring the Gemini spacecraft 0:06:24.040 --> 0:06:28.120 in nose first, and it would dock into this cone 0:06:28.160 --> 0:06:31.680 shaped section of the target vehicle. And then once you're 0:06:31.720 --> 0:06:34.839 in place, docking latches would close to secure the two 0:06:34.880 --> 0:06:38.880 spacecraft together. The target vehicle could then engage its propulsion 0:06:38.960 --> 0:06:42.360 systems after it docked, and that would mean that NASA 0:06:42.560 --> 0:06:45.559 back on ground could change the orbit of the pair 0:06:45.640 --> 0:06:49.920 of docked spacecraft using the target vehicle's engines. So imagine 0:06:49.960 --> 0:06:54.760 for a moment how monumentally challenging this is to do. 0:06:55.360 --> 0:06:57.119 And this is going to require us to talk about 0:06:57.120 --> 0:06:59.800 some math. Now, it's pretty simple math when you get 0:06:59.800 --> 0:07:02.440 down to it. The formula is not terribly complicated, but 0:07:02.520 --> 0:07:05.560 it is mass that has to do with some pretty 0:07:05.600 --> 0:07:10.320 wicked numbers. First, the two spacecraft are in orbit around 0:07:10.360 --> 0:07:13.640 the Earth. So to stay in orbit, to to get 0:07:13.680 --> 0:07:19.960 into an orbit around a celestial body, that satellite, that 0:07:20.200 --> 0:07:25.560 spacecraft has to maintain orbital velocity. This is the velocity 0:07:25.600 --> 0:07:30.160 required to keep a steady orbit at a specific distance 0:07:30.280 --> 0:07:35.280 away from a celestial body and that amount that that's 0:07:35.280 --> 0:07:39.960 that velocity, that speed if you prefer which is less precise, 0:07:40.040 --> 0:07:43.200 but we'll go with speed. It's very common term. The 0:07:43.280 --> 0:07:47.560 speed depends upon the mass of the body you're orbiting, 0:07:48.240 --> 0:07:50.760 so in this case it would be the Earth uh. 0:07:50.800 --> 0:07:55.080 And also the radius that or the distance between you 0:07:55.240 --> 0:07:59.120 and the center of that mass. There's also a gravitational 0:07:59.160 --> 0:08:03.000 constant that you have to factor into this, that's universal. 0:08:03.280 --> 0:08:08.080 The universal gravitational constant is the same number wherever you are. UH. 0:08:08.280 --> 0:08:13.600 In case you're curious, the universal constant gravitational constant is 0:08:13.800 --> 0:08:18.000 six point six seven three times ten to the power 0:08:18.040 --> 0:08:23.480 of negative eleven Newton meter squared per kilogram squared. And 0:08:23.800 --> 0:08:26.640 that number is what you would multiply by the mass 0:08:26.640 --> 0:08:28.600 of the body you're orbiting, so the mass of the Earth. 0:08:29.040 --> 0:08:32.600 Then you would divide that product. You know, you multiply 0:08:32.600 --> 0:08:35.320 those two numbers together, you get a product. You divide 0:08:35.320 --> 0:08:38.360 that by the distance between you and the center of 0:08:38.400 --> 0:08:42.440 the Earth. Then once you take that solution, you would 0:08:42.480 --> 0:08:45.280 take the square root of that and that would give 0:08:45.320 --> 0:08:48.240 you your orbital velocity, how fast you need to go 0:08:48.280 --> 0:08:51.440 in order to maintain your orbit. So if you were 0:08:51.440 --> 0:08:55.800 trying to orbit the Earth at four kilometers above the surface, 0:08:56.400 --> 0:09:00.760 how fast would you need to go? What would your 0:09:01.000 --> 0:09:04.400 orbital speed need to be so that you would maintain 0:09:04.880 --> 0:09:09.719 that orbital distance from the Earth. Well, the Earth has 0:09:09.760 --> 0:09:12.800 a mass of five point nine eight times ten to 0:09:12.880 --> 0:09:17.640 the twenty four power rams and the gravitational constant, as 0:09:17.640 --> 0:09:20.120 I mentioned earlier, is that six point six seven three 0:09:20.160 --> 0:09:23.400 times ten to the power of minus eleven. So if 0:09:23.440 --> 0:09:26.360 we multiply both of those together, that gives us the 0:09:26.400 --> 0:09:30.800 product of three point nine nine zero four five four 0:09:31.240 --> 0:09:35.319 times ten to the four power. That's our product. Okay, 0:09:35.320 --> 0:09:38.160 so that's the top of our fraction. Right, let's talk 0:09:38.200 --> 0:09:42.120 about distance. That's the bottom of our fraction. The Earth's 0:09:42.240 --> 0:09:46.120 radius is six thousand, three kilometers and your four hundred 0:09:46.160 --> 0:09:49.800 kilometers higher than that because you're four kilometers above the surface. 0:09:50.240 --> 0:09:51.960 So you have to take both of those numbers and 0:09:52.000 --> 0:09:55.559 add them together. Let's also convert it to meters. It 0:09:55.600 --> 0:09:57.560 will make life easier for us in the long run. 0:09:58.160 --> 0:10:02.359 That would give us six million, seven hundred eighty thousand meters. 0:10:02.400 --> 0:10:05.760 That's the distance between you and the center of the Earth. 0:10:06.600 --> 0:10:09.760 So that's the bottom of our fraction. We divide our 0:10:09.800 --> 0:10:13.360 earlier product by this number six million, seven hundred eighty thousand. 0:10:13.720 --> 0:10:17.720 That gives us the very easy to describe number fifty 0:10:17.880 --> 0:10:21.360 eight million, eight hundred fifty six thousand, two hundred fifty 0:10:21.440 --> 0:10:25.679 three point six eight seven three. So that's our our 0:10:25.960 --> 0:10:29.120 answer there. Then we have to take the square root 0:10:29.160 --> 0:10:31.760 of that. Taking the square root of that will give 0:10:31.880 --> 0:10:34.880 us our velocity. If you take the square root and 0:10:34.880 --> 0:10:37.160 then you have to round up a little bit, it 0:10:37.320 --> 0:10:41.320 is approximately seven thousand, six hundred seventy two meters per second, 0:10:41.400 --> 0:10:43.440 So that's the speed you have to maintain to stay 0:10:43.440 --> 0:10:47.000 in orbit. That's about four point seven seven miles per second, 0:10:47.480 --> 0:10:51.000 or seventeen thousand, one hundred seventy two miles per hour. 0:10:51.240 --> 0:10:54.880 So you've got these two spacecraft traveling at four hundred 0:10:54.920 --> 0:10:57.400 kilometers above the surface of the Earth. They're traveling at 0:10:57.520 --> 0:11:03.120 seventeen thousand, one seventy two miles per hour each. Then 0:11:03.200 --> 0:11:04.760 you want the two of them to meet up in 0:11:04.840 --> 0:11:10.000 space and dock with one another, which is terrifying. Right. Also, 0:11:10.559 --> 0:11:14.120 because you're in space, you're in an environment where if 0:11:14.160 --> 0:11:18.160 you damage your spacecraft it was it's gonna lead to 0:11:18.800 --> 0:11:22.400 catastrophic decompression. And you're going to have a really bad 0:11:22.440 --> 0:11:25.120 time of it. You can't afford to make any mistakes. 0:11:25.160 --> 0:11:27.680 You have to have this be very, very precise. The 0:11:27.720 --> 0:11:30.600 equation also tells us by the way that the closer 0:11:30.640 --> 0:11:33.240 you are to the Earth, the faster you have to 0:11:33.320 --> 0:11:37.440 travel in order to maintain orbital velocity. That also means 0:11:37.760 --> 0:11:41.160 that you'll make several full orbits around the Earth within 0:11:41.200 --> 0:11:44.360 a single Earth day. You're actually you're going around the 0:11:44.360 --> 0:11:47.880 Earth faster than the Earth's rotation. But the further out 0:11:47.920 --> 0:11:51.720 you go, the less velocity you need to maintain your orbit. 0:11:52.160 --> 0:11:54.480 So if you're pretty far out there, and we're talking 0:11:56.280 --> 0:12:00.120 miles above the Earth, your orbital speed only needs to 0:12:00.120 --> 0:12:04.959 be about six thousand eighty miles per hour, significantly less 0:12:04.960 --> 0:12:08.000 than that seventeen thousand I was talking about earlier. If 0:12:08.040 --> 0:12:10.960 it's at that speed, you will make one full orbit 0:12:11.000 --> 0:12:13.720 of the Earth every twenty four hours, which means that 0:12:13.800 --> 0:12:18.320 if you are located above the equator, you'll essentially be 0:12:18.400 --> 0:12:21.960 in a locked position relative to the Earth. You will 0:12:22.000 --> 0:12:26.120 stay above that that point on the Earth, and you 0:12:26.120 --> 0:12:29.319 will maintain your position relative to the Earth because the 0:12:29.360 --> 0:12:34.120 Earth and you are traveling at a way where the 0:12:34.120 --> 0:12:37.280 Earth's rotation and your orbit are staying in alignment the 0:12:37.440 --> 0:12:41.920 entire time. That's where you get into that geo stationary orbit. 0:12:42.880 --> 0:12:45.880 If you have a satellite geo stationary orbit, it is 0:12:45.960 --> 0:12:49.560 at this very high orbit and it's essentially somewhere near 0:12:49.600 --> 0:12:52.840 the equator, so it can maintain its relative position above 0:12:52.920 --> 0:12:55.920 the Earth. By the way, you need that velocity to 0:12:55.960 --> 0:12:59.960 be right, because if you go slower than orbital velocity, 0:13:00.360 --> 0:13:03.760 your orbit will gradually decay and you will get drawn 0:13:03.880 --> 0:13:06.959 towards the planet, which will ultimately mean re entering the 0:13:07.080 --> 0:13:11.640 Art's atmosphere and landing or burning up. If you're going 0:13:11.840 --> 0:13:16.160 faster than orbital velocity, you will gradually move further out 0:13:16.320 --> 0:13:20.960 from the planet, assuming that you are capable of keeping 0:13:20.960 --> 0:13:23.880 that that speed, and if you're going fast enough, you'll 0:13:23.880 --> 0:13:27.160 attain escape velocity from the planet's gravitational pull and you'll 0:13:27.200 --> 0:13:29.720 just go off into space somewhere. Now, the reason I 0:13:29.760 --> 0:13:32.960 even cover this so thoroughly is that the Apollo missions 0:13:33.440 --> 0:13:37.880 and the soil Use spacecraft both have docking capabilities. In fact, 0:13:38.120 --> 0:13:43.240 for Apollo's lunar missions, docking was absolutely necessary, as it 0:13:43.320 --> 0:13:46.160 was how the lunar landing module was able to rendezvous 0:13:46.200 --> 0:13:49.520 and reconnect with the rest of the spacecraft, which would 0:13:49.559 --> 0:13:52.719 remain in lunar orbit. Now, when I come back, i'll 0:13:52.760 --> 0:13:55.800 talk more about the Apollo program and the amazing achievement 0:13:55.800 --> 0:13:58.760 of putting astronauts on the Moon. But first let's take 0:13:58.880 --> 0:14:09.880 a quick break and thank our sponsor. The Apollo spacecraft, 0:14:10.200 --> 0:14:14.160 when you're looking at the actual lunar missions, was essentially 0:14:14.360 --> 0:14:18.600 a three part craft. Only one of those parts, called 0:14:18.640 --> 0:14:22.120 the Command module, was designed to land back on Earth 0:14:22.120 --> 0:14:26.000 in a retrievable fashion. The three parts were the Command 0:14:26.080 --> 0:14:29.360 module that was the section with all the flight controls. 0:14:29.400 --> 0:14:32.440 That's where the crew would sit during takeoff and normal 0:14:32.480 --> 0:14:36.800 operations and landing. Then there was the Service module. This 0:14:36.880 --> 0:14:39.400 was kind of like the the big container that had 0:14:39.440 --> 0:14:44.200 all the propulsion systems and spacecraft support systems, had an 0:14:44.200 --> 0:14:47.560 engine on it for firing. Those two parts of the 0:14:47.600 --> 0:14:50.800 spacecraft would remain together for most of the mission, and 0:14:50.840 --> 0:14:54.720 the third segment was the lunar module, which would have 0:14:54.880 --> 0:15:00.160 to dock with the Command Service Module or cs UM. 0:15:00.400 --> 0:15:03.200 They would often group these two modules together and just 0:15:03.200 --> 0:15:05.840 call them CSM. The lunar module would have to dock 0:15:05.920 --> 0:15:09.480 with CSM in space, then separate once it was in 0:15:09.640 --> 0:15:13.680 lunar orbit land on the Moon, lift off from the Moon, 0:15:14.600 --> 0:15:19.560 rendezvous with the CSM REDOC, and then the astronauts would 0:15:19.600 --> 0:15:22.160 move back over to the c s M, whereupon they 0:15:22.160 --> 0:15:25.800 would jettison the lunar module and travel back home. Thus, 0:15:25.920 --> 0:15:28.960 that's why that's why the Gemini docking procedure was so important. 0:15:29.000 --> 0:15:32.480 It was sort of a proof that this strategy was 0:15:32.520 --> 0:15:35.520 going to work because the strategy of getting astronauts on 0:15:35.680 --> 0:15:40.400 and off the Moon depended upon that capability. The Command 0:15:40.480 --> 0:15:45.080 Service Module UH would pretty much stay connected up until 0:15:45.320 --> 0:15:47.680 you get to where it was time to re enter 0:15:48.120 --> 0:15:51.960 the r atmosphere, whereupon the command module would jettison the 0:15:52.000 --> 0:15:54.960 service module and it would just become that sort of 0:15:55.800 --> 0:15:59.200 cone shaped spacecraft that we're all familiar with. The heat 0:15:59.240 --> 0:16:02.040 shield was on the bottom of that section, and that's 0:16:02.080 --> 0:16:05.280 what would point toward the Earth while the spacecraft would 0:16:05.280 --> 0:16:09.240 reenter Ther's atmosphere. Now, the three modules attached to an 0:16:09.320 --> 0:16:13.160 upper stage of a rocket in a special housing. The 0:16:13.200 --> 0:16:17.440 stage was called the S four B. The CSM would 0:16:17.800 --> 0:16:21.440 separate from this special casing that was attached to the 0:16:21.640 --> 0:16:24.680 S four B, and the lunar module would still be 0:16:24.840 --> 0:16:28.360 inside that casing, which then would kind of have the 0:16:28.440 --> 0:16:32.240 walls flange outward. People referred to it as looking like 0:16:32.280 --> 0:16:35.280 an angry alligator, although it was an angry alligator with 0:16:36.160 --> 0:16:40.360 four jaws, not too which is really terrifying. And then 0:16:40.520 --> 0:16:43.960 the CSM, the Command Service module, could dock with a 0:16:44.040 --> 0:16:47.400 lunar module which would then detach from the S four B, 0:16:48.320 --> 0:16:50.720 and then you would have your Apollos spacecraft that could 0:16:50.760 --> 0:16:53.280 continue on toward the Moon, whereas the S four B 0:16:53.840 --> 0:17:00.560 would then inject itself into a trajectory, either a solar 0:17:00.600 --> 0:17:04.320 trajectory for the early missions or later on a lunar 0:17:04.359 --> 0:17:11.359 trajectory where the Annassa was really testing impact spacecraft impact 0:17:11.440 --> 0:17:15.040 with the Moon. They had a lot of UH sensors 0:17:15.080 --> 0:17:19.240 aboard the S four B that would give them data 0:17:19.359 --> 0:17:22.720 about impacting it with the Moon. They just made sure 0:17:22.760 --> 0:17:24.960 that obviously that the S four B was going to 0:17:25.080 --> 0:17:27.119 hit a part of the Moon that was nowhere close 0:17:27.160 --> 0:17:29.880 to where the astronauts were going to be. Before there 0:17:29.920 --> 0:17:34.800 were any astronauts in any Apollo spacecraft, NASA held a 0:17:34.840 --> 0:17:38.840 series of unscrewed missions. They were called the Apollo Saturn 0:17:39.040 --> 0:17:42.879 uncrewed missions. The first three of these carried a designation 0:17:42.880 --> 0:17:46.320 that began with a S. So the first of those 0:17:46.480 --> 0:17:49.399 was the A S two oh one, the second was 0:17:49.440 --> 0:17:51.840 called A S two o two, and the third a 0:17:52.040 --> 0:17:54.000 S two oh three, although I should point out A 0:17:54.200 --> 0:17:59.159 S two oh three launched before a S two oh two. Uh, 0:17:59.320 --> 0:18:02.360 they were close together in launch, but two or three 0:18:02.440 --> 0:18:06.000 technically went up first. They also were meant to test 0:18:06.280 --> 0:18:10.080 different things. It wasn't like NASA was just repeating the 0:18:10.080 --> 0:18:12.120 same test over and over. Each test had its own 0:18:12.119 --> 0:18:16.800 mission objectives. They were designed to test the operation of 0:18:16.840 --> 0:18:19.680 the launch vehicles and make sure that they could launch 0:18:19.760 --> 0:18:22.800 the load of an Apollo spacecraft into orbit. You know, 0:18:22.920 --> 0:18:25.280 make sure that the thing you have, the rocket you 0:18:25.280 --> 0:18:29.000 have built, can actually carry the payloads safely up into space. 0:18:29.080 --> 0:18:32.040 That's a big deal. And in an upcoming episode, I'm 0:18:32.040 --> 0:18:35.840 going to focus more on rockets and launch vehicles and 0:18:35.840 --> 0:18:38.920 talk about the science and technology behind those, So we'll 0:18:38.920 --> 0:18:42.240 save all of that discussion for later. The mission objective 0:18:42.520 --> 0:18:45.240 for the first of these, the A S two oh one, 0:18:45.640 --> 0:18:48.760 is described by NASA like this. This is a quote 0:18:48.960 --> 0:18:54.320 from their website. Achieved structural integrity and compatibility of launch 0:18:54.440 --> 0:18:58.919 vehicle as well as launch loads demonstrated separation of first 0:18:58.960 --> 0:19:02.439 and second stages of Saturn l e S and boost 0:19:02.520 --> 0:19:06.439 protective cover from the Command and Service Module or CSM. 0:19:06.600 --> 0:19:11.639 Demonstrated separation of CSM from Instrument Unit, spacecraft and Lunar 0:19:11.720 --> 0:19:16.800 Module adapter, as well as CM separation from the s M. 0:19:16.920 --> 0:19:21.400 Verified operations of Saturn propulsion guidance and control and electrical 0:19:21.440 --> 0:19:26.359 subsystems partially achieved verification of spacecraft subsystems and heat shield 0:19:26.440 --> 0:19:29.280 for re entry from Low Earth orbit due to loss 0:19:29.359 --> 0:19:34.520 of data during maximum heating. Demonstrated operation of mission support facilities. 0:19:34.720 --> 0:19:37.040 So what does that mean, Well, it meant that they 0:19:37.040 --> 0:19:39.920 were testing the launch vehicle making sure that the rocket 0:19:39.920 --> 0:19:45.440 was separating properly in order to get the spacecraft into space. 0:19:45.960 --> 0:19:48.760 So the rocket had several sections and each section needed 0:19:48.760 --> 0:19:51.320 to separate cleanly from the others in order for this 0:19:51.400 --> 0:19:55.520 process to work. They also made sure that the command 0:19:55.560 --> 0:19:58.600 module and the service module would separate properly because the 0:19:58.640 --> 0:20:00.600 command module had to be on its own in order 0:20:00.640 --> 0:20:04.120 for re entry that happened safely. And then they were 0:20:04.160 --> 0:20:07.600 testing out some of the spacecraft subsystems. But as they 0:20:07.600 --> 0:20:12.000 mentioned in the mission over objective and mission Briefing, UH 0:20:12.119 --> 0:20:14.879 This did not go without a hitch. There was a 0:20:14.920 --> 0:20:18.840 loss of some data due to heating, so they didn't 0:20:19.119 --> 0:20:22.760 It's it's not necessarily the case that the systems didn't work, 0:20:23.080 --> 0:20:24.800 but we didn't have the data to know one way 0:20:24.880 --> 0:20:28.000 or the other because of this heating issue. AS two 0:20:28.000 --> 0:20:32.280 A one launched on February nineteen sixty six, and it 0:20:32.400 --> 0:20:35.399 was a short mission. It lasted only thirty seven minutes 0:20:35.600 --> 0:20:41.000 from liftoff to touchdown. The mission had several technical malfunctions, 0:20:41.119 --> 0:20:45.240 including three serious ones, which is why engineers do unmanned 0:20:45.280 --> 0:20:47.720 tests in the first place, to identify and solve those 0:20:47.760 --> 0:20:51.639 problems before human lives are ever at stake. This was 0:20:51.680 --> 0:20:54.680 a suborbital mission. It did not go into orbit. It 0:20:54.720 --> 0:20:57.639 went up to a very high altitude, but it was 0:20:57.680 --> 0:21:03.160 a sub orbital test. The following mission, on August nineteen 0:21:03.280 --> 0:21:07.439 sixty six, this is a S two oh two, was 0:21:07.520 --> 0:21:10.760 the first to test the fuel cell power system that 0:21:10.800 --> 0:21:13.639 would power the spacecraft. Now I've talked about fuel cells 0:21:14.080 --> 0:21:16.840 in other episodes. I've got another episode I have planned 0:21:16.840 --> 0:21:19.280 where I'm going to talk more about fuel cells, so 0:21:19.280 --> 0:21:20.760 I'm not going to go into it here. It's a 0:21:20.760 --> 0:21:24.960 really interesting technology, but we'll cover it more in a 0:21:25.000 --> 0:21:27.000 future episode, and if you really want to learn more, 0:21:27.080 --> 0:21:29.359 you can look at the tech Stuff archives and find 0:21:29.359 --> 0:21:32.879 an old episode where we talk about fuel cells. Like 0:21:33.080 --> 0:21:35.720 the a S two oh one mission, the two oh 0:21:35.760 --> 0:21:39.639 two was also suborbital. This one lasted ninety three minutes 0:21:39.680 --> 0:21:42.639 from liftoff to touchdown, and it proved the design of 0:21:42.680 --> 0:21:46.520 the heat shield for the spacecraft worked as was intended. 0:21:47.119 --> 0:21:49.160 The two oh three unmanned mission, the one that took 0:21:49.200 --> 0:21:51.720 place in between two oh one and two or three, 0:21:52.320 --> 0:21:55.520 was actually an orbital mission. It went all the way 0:21:55.560 --> 0:21:57.720 up into orbit. So you might say, well, why is 0:21:57.760 --> 0:22:01.880 this one designated two oh three when one it happened 0:22:02.600 --> 0:22:05.720 before to oh two, and why did it go into 0:22:05.800 --> 0:22:08.280 orbit when two o two didn't. Well, two oh three 0:22:08.400 --> 0:22:12.240 did not carry a command module or a service module 0:22:12.359 --> 0:22:14.720 or a lunar module. The main purpose of two oh 0:22:14.720 --> 0:22:17.159 three was to test the propulsion system that would boost 0:22:17.160 --> 0:22:20.720 an Apollo spacecraft from Earth orbit to insert it into 0:22:20.840 --> 0:22:24.520 a learned lunar orbit. So the S four B was 0:22:24.560 --> 0:22:28.359 a very important component here, but the actual spacecraft was 0:22:28.440 --> 0:22:32.120 not included in this. And now to get to what 0:22:32.280 --> 0:22:36.320 was originally designated as a S two oh four. This 0:22:36.400 --> 0:22:39.840 is one of the tragedies of the U S space program. 0:22:39.880 --> 0:22:43.720 There have been a few, and this was a pretty 0:22:43.760 --> 0:22:45.720 This was a terrible one. It wasn't a pretty bad one. 0:22:45.760 --> 0:22:49.440 This was a terrible one. It happened on January nine. 0:22:50.960 --> 0:22:54.439 This was supposed to be the first manned mission on 0:22:54.480 --> 0:22:57.520 an Apollo spacecraft, and it was intended to be a 0:22:57.560 --> 0:23:00.800 suborbital flight, so it wasn't meant to go into Earth orbit. 0:23:00.840 --> 0:23:02.760 It was meant to go up to space and come 0:23:02.840 --> 0:23:06.240 right back down again. I was supposed to test Apollos 0:23:06.480 --> 0:23:11.000 systems with actual human beings aboard, and the astronauts aboard 0:23:11.080 --> 0:23:14.000 were Virgil Grisom, he had been one of the original 0:23:14.040 --> 0:23:18.600 Mercury seven astronauts, Edward White, who was the first American 0:23:18.640 --> 0:23:21.919 to walk in space during the Gemini four mission, and 0:23:22.119 --> 0:23:26.400 Roger Chaffee, who had served on the ground on various missions, 0:23:26.400 --> 0:23:29.439 but this was his first chance to fly in a 0:23:29.480 --> 0:23:32.879 mission as an astronaut. They were inside the command module 0:23:33.480 --> 0:23:36.960 when during a pre flight test, a fire swept through 0:23:37.160 --> 0:23:41.200 the module and all three astronauts lost their lives. This 0:23:41.800 --> 0:23:47.920 was a terrible tragedy. NASA immediately started an investigation into 0:23:47.920 --> 0:23:51.199 the accident and suspended all crude missions for more than 0:23:51.240 --> 0:23:54.960 a year. As a result, they did continue working on 0:23:55.280 --> 0:24:00.440 uncrude tests, testing the lunar module, in particular, by they 0:24:00.440 --> 0:24:05.800 were absolutely concerned. They wanted to make absolutely certain that 0:24:05.840 --> 0:24:09.280 they eliminated the possibility as best they could of such 0:24:09.320 --> 0:24:12.879 an accident happening again, and it was a terrible loss. 0:24:13.280 --> 0:24:17.080 Later in nineteen sixty seven, Dr. Georgie Muller, who was 0:24:17.119 --> 0:24:21.640 the Associate Administrator for Manned space Flight at NASA, announced 0:24:21.880 --> 0:24:24.880 that the mission was retroactively going to be named the 0:24:25.040 --> 0:24:28.720 Apollo one, so it's no longer a S two O four. 0:24:29.520 --> 0:24:35.040 It was Apollo one. The next unscrewed mission was Apollo four, 0:24:35.640 --> 0:24:38.879 and that happened on November nine, nineteen sixty seven. Also 0:24:38.960 --> 0:24:40.680 at this time, I think it's interesting to point out 0:24:40.680 --> 0:24:43.920