Get in touch with technology with tech Stuff from how stuff works dot com. Hey there, and welcome to tech Stuff. I am your host, Jonathan Strickland. I'm an executive producer with how Stuff Works, and I love all things tech. And we are, in fact continuing our journey into space, or at least the history of space travel. And I know we talked a lot about space. We're gonna be talking more about space for the next few episodes because it's a fascinating topic and I love looking into it and there's so much to talk about. The this episode, we're going to focus on the later Apollo missions, and we will also switch over and talk about the development of the Soyuz spacecraft, the Soviet spacecraft that was intended to be a competitor to Apollo and is a workhorse for space travel now, I mean, it's the only spacecraft spoiler alert that will actually bring people back and forth between the International Space Station. In upcoming episodes, I'll talk more about launch vehicles, which we frequently will refer to as rockets, and I will also talk about the Space Shuttle program, and then after that we will move on to non space related topics. I know it talked a lot about it, but I could have gone into even more detail about the various spacecraft in their subsystems and how they all worked, but I realized that it would be over at kill and I didn't want to go absolutely nuts. So let's pick up where we left off, which was after the return of the Apollo eleven capsule. Now, Apollo eleven wasn't just a phenomenal achievement in science, engineering, astronaut training, although it was definitely all of those things, but it was also effectively the end of the space race that had started when the Soviet Union launched sput Nick into orbit and put that out as the first man made satellite in Earth orbit. The Soviets had won those early victories, Sputnik being the first one, but also they were the first to put a human into orbit. They were the first to put a woman into space, but the Americans had managed to be the first two docs spacecraft in orbit, and no one else was able to put people on the Moon, although the Soviets did try to do that too, and I'll talk more about those efforts later in this episode. Apollo eleven pretty much sealed the deal, and after that success, the space race was effectively over. Symbolically, it would not be over for a few more years, but the Apollo projects still had several more missions before it would end. Apollo eleven was not the end of the Apollo program. Apollo twelve was the second mission to have a lunar landing. The crew would deploy tech called the Apollo Lunar Surface Experiments Package or all SEP a l s EP. This was a collection of geophysical instruments. Apollo eleven had a more modest collection of experiments that they carried. That one was called the Early Apollo Surface Experiments Package or a SEP. That one had two official experiments and then two additional experiments that were not officially part of a SEP. This is where I start looking into NASA records and I say, what's the difference between officially being part of something and not officially being part of something but still going along for the ride of being left on the Moon. But maybe that's just me getting confused by semantics. NASA on Apollo eleven was mostly focused on landing people on the freaking Moon and then getting them back home safely, So science was sort of a secondary priority, right. It was not the highest priority for NASA. For that. For the Apollo eleven mission, they had some scientific experiments they wanted to include, but mostly they just wanted to concentrate on getting people on the Moon and then getting them back home safely. The purpose of all SEP was to monitor the environment of and a region close to the Apollo landing site for at least a year after the end of the visit to the Moon. Apollo seventeens version of all SEP was designed to to operate for two years, and so there The Apollo twelve one was just the first all step. All of the other following Apollo missions would bring similar packages along. Some of them worked for up to eight years before Mission control would shut down all remaining all SEP projects on September nineteen seventy seven, so some far outlasted their their projected useful lifespan. The all SEPs history is pretty darn interesting all in its own right. It's it's just the the list of experiments is fascinating. The projects started way back in March nineteen sixty three, so they knew that the plan was to go to the Moon. Kennedy had made the announcement in nineteen sixty one, But what could we do once we got there, what kind of data would we try to collect? And that began a long series of discussions to select which experiments would be conducted on the Moon's surface, And they had to consider a lot of different factors when they were making these choices, not just what was going to be the most scientifically interesting, that was obviously one of the really important factors, but also what was just going to be practical, because the experiments would need to be relatively simple in design, because there was no chance of sending out a technician to repair a complicated piece of equipment once the lunar module would lift off the Moon. You know, you can't make a service call and have a repairman go to the Moon to fix something. They also could not be too heavy, both for the purposes of planning out the payload for the launch vehicle, but also how you deploy it. How How would you know cause the astronauts the how would they actually take it out of the lunar module, take it to the rights it and set it up it. It was too heavy and too complex. Although really heavy wasn't the big problem. Bulky was the problem. I mean, on the Moon you have one six the Earth's gravity, so it would have to be incredibly heavy to be problematic, but bulky was an issue that and where the weight was distributed was an issue. There were several all steps where astronauts found it difficult to carry them, not because necessarily the weight, but because there was no convenient way to carry them on the Moon's surface. During those discussions, Nassa identified questions that scientists felt we should try to answer with these experiments. So before designing any equipment or deciding what technology to send along, they said, well, what is it exactly do we want to learn, and that that will guide us into designing these experiments. So those questions included stuff like, what is the internal structure of the moon, What is the actual geometric shape of the moon? What is the present inter internal energy regime sam of the Moon? Where where is energy going? Is the Moon shedding energy as it absorbing energy? Was the composition of the lunar surface wasn't made out of cheese? It turns out no, What principal processes were responsible for the present structure of the Moon. Why is the Moon the way it is? Was the present tectonic pattern and distribution of tectonic activity on the Moon are their moon quakes? What are the dominant processes of erosion, transport and deposition of material on the lunar surface? How does this stuff move around? What volatile substances are present on or near the lunar surface? Is there any evidence of organic or proto organic molecules on the Moon? How old is the Moon? And what is the history of dynamic interaction between the Earth and the Moon. A follow eleven's ACEP contained a passive seismic experiment package, so it would measure essentially moon trimmers, and it had four seisometer is that were powered by two solar panels, and that would that would study any moon quakes or vibrations from meteorite impacts, and it would ultimately record somewhere between a hundred and two hundred meteorite impacts during the course of its useful lifespan. The second experiment on the ace UP, the official experiment, was a lunar dust detector that would measure the amount of dust accumulating on the lunar surface and would also monitor damage to solar cells caused by high energy radiation. Because the Moon does not have the same level of protection from radiation as the Earth does. Lacking an atmosphere, it doesn't absorb as much of that radiation outside of the surface. That is in addition to the two official DECEP experiments, they did have two other ones I mentioned earlier. Those were a lunar ranging retro reflector, which is a fancy way of saying a very reflective surface. It was actually an array of one cubes made of fused silica, and this reflect the surface was positioned on the Moon so that if you had a sufficiently powerful laser beam and you knew exactly where that reflective surface was, you could aim the laser beam at the surface and have it reflect back to the Earth. And if you did that with a laser and a sensor, so that you've fired the laser and then you had a sensor there to detect what the time difference was between firing the laser and picking up the reflection, you could get very precise measurements of how far away the Moon was, to a degree of accuracy of up to eight centimeters, which is pretty incredible. You know how close the Moon was within eight centimeters. That experiment was operational until June. The solar wind composition experiment was the second non ACEP experiment deployed by buzz Aldron during Apollo eleven, and it used a panel of alunium foil, which was really pretty much the same stuff is what you would use to wrap up leftovers, and that foil panel was it to collect atomic particles that were emitted by the Sun. That experiment wasn't left on the Moon, so instead they deployed it. They unfolded it and set it up and then left it alone for about an hour or so and then collected it and stored it in the Lunar Module, and they brought it back aboard the Man's Service Module on the return trip home, and once they landed, they turned over that experiment to a group of scientists from Switzerland. It was the group of scientists who had actually designed that experiment. The step and the all set packages called the Scientific Equipment Bay aboard the Lunar Module their home until landing on the Moon. This bay, it's kind of like a trunk in a car in a way. It was designed so that would allow for easy unloading on the Moon's surface, so it's height with such that the astronauts didn't have to try and bend far down in those big bulky spacesuits to get that things, they could kind of reach and grab it and pull it out. The bay also had boom arms that would help offload materials, particularly the bulky ones that might require both astronauts to work together. Remember, the lunar module would have two astronauts in it and the command module would have the third astronauts still in orbit around the Moon. Uh This was important to have those boom arms because sometimes the lunar module would land in such a way that it wasn't really level on the Moon's surface. You might land at the edge of a little dip, or one of the legs of the lunar module might sink a little further into the dust on the surface, So they wanted to make sure they had systems in place to help with the unloading in case the lunar module wasn't perfectly level. The general procedure for deploying the all set packages was that you would have to find a spot about a hundred meters to the west of the lunar module and make sure that you were not in the shadow the path of the shadow of the lunar module for sunrise, because solar panels would often be part of those experiments, So you needed to have uh unblocked access to sunlight, and you had to find someplace that was, you know, fairly level, which was always the Finding areas on the Moon that met these criteria wasn't always easy. The all set aboard Apollo twelve and the ones on each of the Apollo missions following until Apollo seventeen included some other pieces of equipment. Central to the experiment was a station that acted as a power source. It was kind of like a a little power generator right in the middle, and it had a radio isotope thermoelectric generator. And yet that means that the experiments were powered by the heat generated by radioactive material undergoing decay. Specifically, they were using plutonium to thirty eight in oxide form. The generator could produce seventy watts of direct current electricity, and all of the generators from Apollo twelve to seventeen are on the Moon, with the exception of one, the generator for Apollo thirteen, which was forced to abandon its mission in the wake of an emergency. That generator is somewhere at the bottom of the Pacific Ocean, so they're somewhere in the Pacific Ocean is a radioisotope thermoelectric generator with plutonium to thirty eight in it. Now that meant that all the experiments, and there were many, that these central stations would provide power to actually drew less electricity than what would be needed to power a seventy five what lightbulb, which is pretty incredible. Experiments included stuff like what was uh included in the Apollo eleven package that that was in many of the other ones as well. But the Apollo twelve siometer experiment not only detected when the lunar module crashed into the Moon upon being jettisoned from the Command Service Module, but found that the Moon vibrated or rang like a bell for more than fifty five minutes after that impact. So this was done on purpose the jettison the lunar module. Everyone else was aboard the Command Service module for the return trip home and it was on crash course with the Moon, and it was specifically done so that they could measure the the seismic activity. So why did it vibrate for so long for nearly an hour? Well, according to Dr Ross Taylor, the reason is because the lunar soil is devoid of moisture, which would literally dampen vibrations. Moisture absorbs vibrations, water absorbs them. In fact, when we talk about the Space Shuttle program, I'll talk about how water was used specifically for that purpose. So without moisture, the vibrations could continue much longer than they would on Earth. Other experiments would look into stuff like the heat flow of the Moon. They found that the interior of the Moon is warmer than the surface, so heat flows from the center of the Moon out towards the surface and then dissipates in space. They also had experiments that had magnetoma meters or magnometers if you prefer, but that I'm almost certain that's not the right way to say it. Magneto. They had the x Man magneto or x Man Villain magneto to study the magnetic field of the Moon. They had ion detectors to measure the number and types of ions on the Moon charged particles on the Moon. Mostly those ions were deposited by the solar wind. Other experiments would look for charged particles or cosmic radiation, and the packages on different Apollo missions contained different experiments. Some would be repeated with follow up missions, so you might have an experiment that's on Apollo fourteen that's also on Apollo sixteen. Others were unique to their specific mission. When we come back, i'll talk about an experiment aboard the Apollo seventeen that gave astronauts a bit of a headache when they were deploying it. But first let's take a quick break to thank our sponsor. So one experiment that did not quite go as planned was the Lunar Surface Gravimeter aboard the Apollo seventeen, and scientists at the University of Maryland designed this experiment, and its purpose was to search for evidence of gravity waves. Gravity waves were something that Einstein had predicted in his theories, but no one at that point had found any actual observable evidence of gravity waves, so this device was supposed to look out for that kind of stuff. It was also meant to study the response of the Moon to the Earth's title poll, and it could also supplement data gathered by the various seismometers that were distributed on the Moon's surface. The business end of the experiment, the part that was that at issue was a spring balance that was incredibly sensitive and it had special mass weights attached to it to provide the proper tension on the spring balance. But while designing this particular piece of technology, the team made a mathematical error and the mass was not correct, so it wasn't actually putting enough tension on the spring. The astronauts try to set the experiment to null when calibrating it, and they so setting it to a neutral position, but they foundly couldn't get the meter to register a neutral position, even though they verified the experiment was on a level surface and that the gimbal inside the device could move freely. Only then did NASA realized there was a tiny but sufficiently irritating error. The mass weights were two percent lighter than what they needed to be in order for the device to operate properly. Making things worse, The sensor was adjustable, so you could adjust for error, but it would only adjust to correct for an error of up to one point five cent, and the mass of the weights was a two percent error, so it was greater than what the device could allow for. So they started using some other methods, and one of those methods turned out to be what we in the tech business would tend to call percussive maintenance, which means an astronaut hit the experiment to make it work better. Seriously from a NASA website about this alsup experiment, Schmidt, which is a reference to Apolo seventeen astronaut Harrison Schmidt, wrapped the exposed top plate on the gimble, rocked the experiment in all directions, re leveled the experiment, working the base well against the surface, and verified the sun shade tilt. These actions were taken to free a mass assembly or a sensor beam that was suspected of being caught or bound, but no change was apparent. The problem was at least partly overcome by applying pressure on the beam with the mass changing mechanism beyond the design point, by addition of all included masses so that it contacted the beam much valuable e v A time as extra vehicular activity. About thirty minutes was spent on the attempt, which is kind of a polite way of saying they wasted half an hour trying to get this darn thing to work. All of this is to say that the missions after Apollo Oven we're meant to further our scientific understanding. Numerous experiments would gather information. Some for years after we left the Moon, astronauts would gather samples of the dust and the rocks on the Moon and bring them back. They deployed equipment starting with Apollo fifteen. They also got to tool around on the Moon's surface with the lunar rover. I could do a full episode just about the lunar rover. The Apollo fifteen was the first of Apollo's missions to spend more than just a few hours on the Moon's surface. In fact, the whole mission for Apollo fifteen lasted about twelve days. The CSM pilot spent nearly as much time in lunar orbit as the entire length of the Apollo eight mission. That was the first Apollo eight mission to orbit the Moon. Apollo seventeen, the last of all the missions, launched on December seven, ninety and returned to Earth on December nineteenth, nineteen seventy two. It would be the last time so far that any humans would set foot on the Moon. Now, when I say the last mission, I do mean the last lunar mission. There was one more Apollo mission that I'll talk about a little bit later. Each of these missions were really important, and I could do a full episode about any single one of them. Now, before I transition to talk about the say Us, I thought it would be good to at least talk a little bit about Apollo thirteen and what happened there, because it had the famous malfunction, the subject of many documentaries and films, including the film Apollo thirteen. The mission, which carried astronauts John Swiggert, Fred Hayes, and James Lovell, had a bumpy start. Literally a few minutes after lift off, the astronauts felt a little vibration in the command Service module. The Launch Vehicles center engine shut down two minutes earlier than planned, but the four remaining engines were able to fire for a little bit more than half a minute longer than planned in order to compensate for that early burnout, and the S four B stage had to prepare hell the spacecraft and extra nine seconds as well. But despite all that, everything else seemed to be going really smoothly, so much so that forty six hours into the mission, so nearly two days into the mission, ground control said that the spacecraft was in such good shape and everything was going so smoothly, it was frankly pretty darn boring. Just a little before the fifty six hour of the mission, and oxygen tank in the service module blew up. A second oxygen tank failed, the command module lost electricity, water, and light, and that's when we get the famous phrase, Houston, we've had a problem here, which typically gets paraphrases Houston, we have a problem. The crew would move into the lunar module. Remember with these lunar missions, right after going into orbit, the Command Service module would detach from the S four B and would rendezvous with the S four B two dock with the lunar module on the end of the CSM, So you have the lunar module kind of kind of balanced on the end of the CSM for the rest of the journey to the Moon. So it was already connected to the CSM. So they had this this lunar module where the life support systems were still working. But it wasn't ideal to move everyone in there because the lunar module was meant to support two crew members for less than two days, and instead there would need to be three crew members aboard this lunar module for four days. They also had to cut way back on water consumption because the water was important, not just for them to drink, but also to be used as a cooling system for the various systems aboard the spacecraft. And as a result, because they had to cut so far back on water, they all became severely dehydrated. In fact, collectively the crew would lose thirty one and a half pounds during this mission, almost all of it water weight. So at one point Level had to resort to using the Sun as a navigational star. He had to align the attitude of the lunar module according to the directions he received from ground control, which is pretty phenomenal to think about navigating by the stars when you're out in space. The conditions in that spacecraft were admittedly really tough. The temperature sank down to about thirty eight degrees fahrenheit that's about three degrees celsius, and no one was sure if the command module would power up properly. And the command module was absolutely necessary because that was the spacecraft that was outfitted for re entry. The heat shielding and everything that was on the command module, not the lunar module, so they were still connected at this point. There's a lot of condensation inside the command module. When it became time for them to to transfer back over. That raised a lot of concerns about possible short circuits. When they were powering up the command module, they thought, well, there's a lot of water pooling on the surface. There's probably water underneath the panels as well, which could make a short circuit issue. The astronauts were able to jettison the service module from the command module, and they were able to use the lunar module's propulsion system to pull away from the service module to a safe distance so that it wouldn't collide with the rest of the craft. And then before re entry, they moved back into the command module, strapped themselves in, they jettisoned the lunar module, and they re entered the art atmosphere. So all of that was amazing. It was phenomenal that they were able to achieve this. The parachute deployed as it was supposed to, they splashed down in the South Pacific Ocean on April seventeenth, nineteen seventy, and that the astronauts and ground control were able to solve these critical problems dynamically. They were able to improvise using various systems that were available to them. They didn't have the full suite of capabilities of the spacecraft available. They had to make do, and their challenge was very real and very critical. It could have ended in tragedy. So this is one of the greatest stories of achievement I've ever read about. When you're talking about, you know, figuring out how to make use of what you've got left in order to to make it out of a terrible situation. So keep in mind, like getting to the Moon was an incredible challenge, right, that was insane in some ways, and it involved years of careful planning and calculations. Getting the crew of Apollo thirteen home in one piece meant that scientists and engineers had to work out creative solutions with limited options in just a couple of days. They didn't have months to plan this out. They had to do it in hours, and they did it. The ultimate cause of the explosion was determined to be a problem with the heaters and the oxygen tanks. Uh The command module had been upgraded to provide sixty five volts of direct current power to these heaters. The older design of the command module had only provided twenty eight volts, so this was a step up and voltage, but the problem was the thermostatic switches on the heaters had not been modified to accept that higher voltage. They were still designed for the volts, so the operation of the heaters ended up creating an overheating problem, and that ended up affecting the wire ring surrounding the heaters, and that in turn degraded the teflon installation around the oxygen tanks and made it possible for that explosion to happen. There was one final flight of the Apollo program that was not part of the lunar missions. It didn't get a number like Apollo seventeen, and that was the Apollo Soyuz mission because it involved a rendezvous and docking with a Soviet Soyuz spacecraft, which happened in nineteen So I figure it's time I take a quick trip over to the USSR to talk about the development and technology of the Soyus, a spacecraft that we still depend upon decades later. But before I do that, let's take another quick break to thank our sponsors. If you've listened to my earlier episodes about the Soviet space program, you know it started with the relatively primitive Vostok spacecraft, which had extremely limited capabilities in space, and then you had the vosh Kod spacecraft, which was like a souped up Vostok, and the Voshkod lacked the carrying capacity to supply a crew of two or three cosmonauts with enough air, water, and food to make a trip to the Moon and back feasible. So the Soviet Union needed a new approach. Those earlier spacecraft really meant to try and get the Soviet Union up into space ahead of the Americans, and to do things like simple, relatively simple docking maneuvers. I use the word simple in relative terms because it's actually incredibly complicated. But it was more of a display of the principle of docking than any useful application of it. Anyway. That was all meant as almost like propaganda or political warfare. But to get to the Moon was going to require more than just these quick fixes. Complicating matters, however, was that the lead designer of Soviet spacecraft, Sergei kor Lev, had died on January fourteenth, nineteen sixty six. Kor Lev was the heart and soul of the Soviet space program. He was very much in charge of design, the lead designer, and he had battled with politicians during much of the space race, he was trying to balance the unrealistic deadlines and the low budgets he was being given by politicians with what he could actually accomplish. He died during a surgical procedure, and his successor, Vasily Mission, had to pick up the pieces, and there was still a lot of political pressure to get the Soviets to the Moon before the Americans. But at this point the Soviets were kind of getting a little bit behind the Americans, especially with launch vehicles, which I'll talk about in the next episode. Originally, the plan was to create a spacecraft that could concern list of three large segments, and each segment would be put into orbit on a different launch vehicle or rocket, and then assembled in orbit by cosmonauts. One stage would contain the crew compartment, while the other two would hold the propulsion system and the fuel tankers. But ultimately the Soviets decided that approach was impractical. Obviously, if there was anything that went wrong with any one of those launches, it would mess up the entire thing, so they scaled it back. Originally, they scaled it back as a two part spacecraft, so it would still need two different launch vehicles, and then ultimately they just said this also probably wasn't the best idea and decided to go with a single launch vehicle spacecraft design. So it was a spacecraft that would only need one launch to get into space and that and that it would just be a complete spacecraft top to bottom. The spacecraft had been updated several times, but in general here's how it shakes out. Because the general design of the Sayers space craft has remained consistent, the details are very very different because obviously technology has advanced considerably since the nineteen sixties. The spacecraft is about twenty three feet or seven meters long. Like the Apollo spacecraft, it consists of three modules, right, the Pollo spacecraft has the command module, the service module, and the lunar module. Well, the sail Us has the orbital module. That one is sort of spherical in shape. It's at one end of the spacecraft, the section UH. The the spherical section has the docking mechanism that would allow the soil Us to dock with other spacecraft or space stations. UH. The Russians put up a couple of space stations in orbit and also participated with the International Space Station. So this is the part of the spacecraft that would dock with those facilities. It also has the living facilities for orbital phases of missions. Behind the orbital module, so if you had it standing up on end, it would be the next section down uh is what is called the descent module. It's kind of shaped like a bell and it has a space for three people. It's used during ascent, descent, and landing, so going up, coming down, and actually when it lands on the ground. Behind this section is a cylindrical module called the service module, which has propulsion, life support, electrical systems for the spacecraft. All of those are located in that section. The first Sawyer's mission with a crew ended tragically. It was supposed to involve to spacecraft. You're supposed to have the Saya's one and the Sawyers two, and the two spacecraft were meant to dock in orbit, and this would have happened in April nineteen sixty seven, about a year after the Gemini eight docked with an unmanned a Gina target vehicle. So while the Americans had already shown a successful orbital rendezvous and sucking, this would actually be a an example of two crude spacecraft to spacecrafts with people in them docking together. Uh. The docking system aboard the Soyus relied on an automatic system, so it didn't require pilot and put the way the Gemini and Apollo ones did with the Soya's two grounded because of whether the Soyuz one was to just return to Earth the day after it launched, so the Sayers two never takes off the Soyas one is in orbit and then is supposed to return the next day. But the parachute for the Soyuz one failed to deploy and cosmonaut Colonel Vladimir Komarov died in the resulting crash. Along with a parachute, the Soyus capsule also had a solid fuel rocket that was intended to ignite one meter before landing to help with a soft landing, since like the Volskad, the Soyus was meant to land on solid ground, which would make it a little less ring. Actually, when you watch video or film, I should say, of the Sawyus landing for the h COD landing, it looks pretty scary because there's a big flash just before it lands. It looks like there's an explosion, but in fact that's the solid fuel rocket that at the last second is giving just that little bit of not a little bit, a considerable amount of thrust in order to reduce the impact of landing. Saya's two was an unmanned craft, and saw Us three, which had a crew, were then meant to conduct the first automatic docking procedure in orbit in October ninety eight. The two spacecraft ended up getting really close to each other, but they did not dock. Saw Us four and five would dock in orbit in January nine. The Sawyers five had a full three cosmonaut crew, the Sawyer's four only had a pilot named Vladimir Shat The Love and the two craft would dock together and two crew members from the Sayus five would transfer over to the Soyas four, and both spacecraft returned to Earth safely. Now, while the Soviets planned to use the Sayers to go to the Moon, they were going to rely on a very similar strategy to Apollo, with a lunar landing module that would put the cosmonauts on the Moon and then return them to rendezvous with the Soyas spacecraft in the lunar orbit. The success of the Apollo eleven mission in nineteen sixty nine effectively made the Soviets cancel those plans because it was gonna be very expensive, very difficult. They had not yet completed the design of the lunar module, and it just didn't make sense to keep going after a goal that the Americans had already achieved. But the Soyus lived on just not as a spacecraft to take people to the Moon, but to take people to orbit. Sure, there was one other Soyo's catastrophe that resulted in the death of an entire crew. This one was was pretty scary and and and sad as well. It happened on June ninety one, and it with the Says eleven. The crew had successfully docked with the Salut one. The Saliot one was the very first space station in Earth orbit. This was also the first successful docking procedure. The Sawyers ten, the mission immediately before Sawyer's eleven, was supposed to dock with the Salut one, but had to abandon the mission after some technical malfunctions had prevented docking. So the crew of the Sayers eleven successfully docked with the space station. They board the space station to actually stay on the space station for twenty three days, but then they disconnect because there was a some technical malfunctions that led to an electrical fire aboard the space station, so for safety, the crew got back aboard their spacecraft, the Sawyers eleven. They disconnected from the space station, they piloted the craft to re enter the Earth's atmosphere. Then we're not entirely certain exactly how things went from there, but the capsule landed, parachute deployed. Everything went as planned, but when the retrieval crew got to the capsule, they found that all three crew members inside had died. An investigation concluded that a pressure valve at some point during re entry had failed and that resulted in a loss of cabin pressure, and the crew were not wearing pressurized suits. The Soviets had decided that pressurized suits would not be necessary with the Soyas, and that tragedy ended up changing the minds of the Soviets, and from that point forward, all Soviet crews were required to wear pressure suits during missions. But because the crew was not wearing them in this one, they died from the rapid depressurization. And I alluded to this earlier, but back in nine there was a special joint mission between the United States and the Soviet Union space agencies. The U S would send up an Apollo Command Service module only given the designation of follow. Some people in the media would informally refer to it as Apollo eighteen, but that was not the official designation. In fact, there had been a planned Apollo eighteen mission, but that had already been canceled. The Saya's spacecraft was technically connected to a mission called Saya's nineteen in the Soviet Union. This was the final flight of an Apollo spacecraft, and the docking pilot for the craft was Donald K. Deek Slayton. He was one of the Mercury Seven, one of the original astronauts picked for the Mercury program. He was the one who was grounded for health reasons when they found an irregularity in his heartbeat, and he finally got the clearance to fly again, so he got to go up into space on the final Apollo mission. The Apollo spacecraft was fitted with a special docking mechanism to make it compatible with the Soya's spacecraft, and the two craft docked on July seventeenth, ninety The crews were able to meet with each other. They shook hands with one another, and that symbolically brought the space race to an end, though again you could argue quite convincingly that the moon landing had effectively done that a few years earlier. Both crews were able to return home safely, although on the return trip home the Apollo crew ended up being exposed to an oxidizer that's really toxic. It's nitrogen tetrox side, and there was a switch that had been left open when it should have been closed, according to the crew. The crew member who claimed responsibility said he did he failed to hear the commander called that out on a checklist, and it was his fault that the the switches were not closed. All three were able to recover. They spent a couple of weeks in a hospital in Honolulu, so not the worst place in the world, although I guess if you're in a hospital room, it's not like you're really enjoying the surroundings. So Sayers was not going to go to the Moon, and instead the focus was on the orbital version of the Sayers. Like the seven K O K variation of the craft. There have been a lot of variations of the Soyos over time. Like I said, there's been a lot of updates, upgrades, variants, but the basic design has remained pretty consistent, just with updated subsystems and materials. For several years. After the space Shuttle program was shut shuttered in two thousand eleven, the Sayers was the only spacecraft capable of docking with the International Space Station that would still be in service to this day. It's the only spacecraft that has is allowed to take people to and from the space station. Space x is Dragon two capsule will eventually be able to do that, assuming everything continues to go well for that program, but for right now, the say Us is the only way up or down if you happen to be a human. Today, the space x Dragon capsule is able to dock with the space station, but only for taking stuff up or bringing stuff back down, stuff being non organic, so we're talking like experiments and things. Uh. Space x is still work with NASA to develop a version of that capsule that will be piloted by a crew. Also, the space station has a Saya's spacecraft docked with it all the time that can be used as an emergency lifeboat, so there's an emergency Soyo's capsule attached to the International Space station, and if there is ever an emergency that requires evacuation, the crew can climb into the Saya's capsule and detach and head home. Um NASA and SpaceX do have a contract for up to six crude flights again crude as a manned not you know, c R E W E D, not c R U D, but they have a contract for up to six of those to this space station. Once that Dragon two capsule is cleared for such duties, and then the Sayers will be just a little less special. The current version of the Sayers has the designation Saya's MS. That one entered service in July. It still has the three module design of its predecessors, so it isn't dramatically different, at least in basic construction, but it does have modern power systems, communication systems, navigation systems, computers, all that kind of thing. Everything has been updated from that perspective. There's also a black box like system inside of it that records voice and data during descent phases, so if anything does ever go catastrophically wrong, the retrieval crew could have a chance of retrieving the black box and studying the data to find out what happened and of course, there's no longer a Soviet Union, says MS now falls under the jurisdiction of the Russian Federal Space Agency. So that's a big difference from when the Sayers was first created, and that kind of concludes my overview of the Apollo missions and the Saya's space spacecraft. I am still amazed the spacecraft that was designed in the nineteen sixties is still being used regularly today, although granted it is obviously updated versions of that same spacecraft. So this was a great journey for me. I learned a lot as I looked into this, and in our next episode, we're gonna dive into the scary world of rocket science. We're gonna talk about these launch vehicles that have been used with various spacecraft, and I'm really going to focus on the launch vehicles for the spacecraft that carried people. I'm not gonna look at a whole lot of the like there were. There have been dozens of launch vehicles, some of which have been used only to put things like satellites and stuff up. I say only there's still in an incredible achievement. But I'm going to focus mainly on the ones that were used to put people up into space. That will be our next episode. But if you have a suggestion for a future episode, maybe it has nothing to do with space, send me an email. 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Get in touch with technology with tech Stuff from how stuff works dot com. Hey there, and welcome to tech Stuff. I am your host, Jonathan Strickland. I'm an executive producer with how Stuff Works, and I love all things tech. And we are, in fact continuing our journey into space, or at least the history of space travel. And I know we talked a lot about space. We're gonna be talking more about space for the next few episodes because it's a fascinating topic and I love looking into it and there's so much to talk about. The this episode, we're going to focus on the later Apollo missions, and we will also switch over and talk about the development of the Soyuz spacecraft, the Soviet spacecraft that was intended to be a competitor to Apollo and is a workhorse for space travel now, I mean, it's the only spacecraft spoiler alert that will actually bring people back and forth between the International Space Station. In upcoming episodes, I'll talk more about launch vehicles, which we frequently will refer to as rockets, and I will also talk about the Space Shuttle program, and then after that we will move on to non space related topics. I know it talked a lot about it, but I could have gone into even more detail about the various spacecraft in their subsystems and how they all worked, but I realized that it would be over at kill and I didn't want to go absolutely nuts. So let's pick up where we left off, which was after the return of the Apollo eleven capsule. Now, Apollo eleven wasn't just a phenomenal achievement in science, engineering, astronaut training, although it was definitely all of those things, but it was also effectively the end of the space race that had started when the Soviet Union launched sput Nick into orbit and put that out as the first man made satellite in Earth orbit. The Soviets had won those early victories, Sputnik being the first one, but also they were the first to put a human into orbit. They were the first to put a woman into space, but the Americans had managed to be the first two docs spacecraft in orbit, and no one else was able to put people on the Moon, although the Soviets did try to do that too, and I'll talk more about those efforts later in this episode. Apollo eleven pretty much sealed the deal, and after that success, the space race was effectively over. Symbolically, it would not be over for a few more years, but the Apollo projects still had several more missions before it would end. Apollo eleven was not the end of the Apollo program. Apollo twelve was the second mission to have a lunar landing. The crew would deploy tech called the Apollo Lunar Surface Experiments Package or all SEP a l s EP. This was a collection of geophysical instruments. Apollo eleven had a more modest collection of experiments that they carried. That one was called the Early Apollo Surface Experiments Package or a SEP. That one had two official experiments and then two additional experiments that were not officially part of a SEP. This is where I start looking into NASA records and I say, what's the difference between officially being part of something and not officially being part of something but still going along for the ride of being left on the Moon. But maybe that's just me getting confused by semantics. NASA on Apollo eleven was mostly focused on landing people on the freaking Moon and then getting them back home safely, So science was sort of a secondary priority, right. It was not the highest priority for NASA. For that. For the Apollo eleven mission, they had some scientific experiments they wanted to include, but mostly they just wanted to concentrate on getting people on the Moon and then getting them back home safely. The purpose of all SEP was to monitor the environment of and a region close to the Apollo landing site for at least a year after the end of the visit to the Moon. Apollo seventeens version of all SEP was designed to to operate for two years, and so there The Apollo twelve one was just the first all step. All of the other following Apollo missions would bring similar packages along. Some of them worked for up to eight years before Mission control would shut down all remaining all SEP projects on September nineteen seventy seven, so some far outlasted their their projected useful lifespan. The all SEPs history is pretty darn interesting all in its own right. It's it's just the the list of experiments is fascinating. The projects started way back in March nineteen sixty three, so they knew that the plan was to go to the Moon. Kennedy had made the announcement in nineteen sixty one, But what could we do once we got there, what kind of data would we try to collect? And that began a long series of discussions to select which experiments would be conducted on the Moon's surface, And they had to consider a lot of different factors when they were making these choices, not just what was going to be the most scientifically interesting, that was obviously one of the really important factors, but also what was just going to be practical, because the experiments would need to be relatively simple in design, because there was no chance of sending out a technician to repair a complicated piece of equipment once the lunar module would lift off the Moon. You know, you can't make a service call and have a repairman go to the Moon to fix something. They also could not be too heavy, both for the purposes of planning out the payload for the launch vehicle, but also how you deploy it. How How would you know cause the astronauts the how would they actually take it out of the lunar module, take it to the rights it and set it up it. It was too heavy and too complex. Although really heavy wasn't the big problem. Bulky was the problem. I mean, on the Moon you have one six the Earth's gravity, so it would have to be incredibly heavy to be problematic, but bulky was an issue that and where the weight was distributed was an issue. There were several all steps where astronauts found it difficult to carry them, not because necessarily the weight, but because there was no convenient way to carry them on the Moon's surface. During those discussions, Nassa identified questions that scientists felt we should try to answer with these experiments. So before designing any equipment or deciding what technology to send along, they said, well, what is it exactly do we want to learn, and that that will guide us into designing these experiments. So those questions included stuff like, what is the internal structure of the moon, What is the actual geometric shape of the moon? What is the present inter internal energy regime sam of the Moon? Where where is energy going? Is the Moon shedding energy as it absorbing energy? Was the composition of the lunar surface wasn't made out of cheese? It turns out no, What principal processes were responsible for the present structure of the Moon. Why is the Moon the way it is? Was the present tectonic pattern and distribution of tectonic activity on the Moon are their moon quakes? What are the dominant processes of erosion, transport and deposition of material on the lunar surface? How does this stuff move around? What volatile substances are present on or near the lunar surface? Is there any evidence of organic or proto organic molecules on the Moon? How old is the Moon? And what is the history of dynamic interaction between the Earth and the Moon. A follow eleven's ACEP contained a passive seismic experiment package, so it would measure essentially moon trimmers, and it had four seisometer is that were powered by two solar panels, and that would that would study any moon quakes or vibrations from meteorite impacts, and it would ultimately record somewhere between a hundred and two hundred meteorite impacts during the course of its useful lifespan. The second experiment on the ace UP, the official experiment, was a lunar dust detector that would measure the amount of dust accumulating on the lunar surface and would also monitor damage to solar cells caused by high energy radiation. Because the Moon does not have the same level of protection from radiation as the Earth does. Lacking an atmosphere, it doesn't absorb as much of that radiation outside of the surface. That is in addition to the two official DECEP experiments, they did have two other ones I mentioned earlier. Those were a lunar ranging retro reflector, which is a fancy way of saying a very reflective surface. It was actually an array of one cubes made of fused silica, and this reflect the surface was positioned on the Moon so that if you had a sufficiently powerful laser beam and you knew exactly where that reflective surface was, you could aim the laser beam at the surface and have it reflect back to the Earth. And if you did that with a laser and a sensor, so that you've fired the laser and then you had a sensor there to detect what the time difference was between firing the laser and picking up the reflection, you could get very precise measurements of how far away the Moon was, to a degree of accuracy of up to eight centimeters, which is pretty incredible. You know how close the Moon was within eight centimeters. That experiment was operational until June. The solar wind composition experiment was the second non ACEP experiment deployed by buzz Aldron during Apollo eleven, and it used a panel of alunium foil, which was really pretty much the same stuff is what you would use to wrap up leftovers, and that foil panel was it to collect atomic particles that were emitted by the Sun. That experiment wasn't left on the Moon, so instead they deployed it. They unfolded it and set it up and then left it alone for about an hour or so and then collected it and stored it in the Lunar Module, and they brought it back aboard the Man's Service Module on the return trip home, and once they landed, they turned over that experiment to a group of scientists from Switzerland. It was the group of scientists who had actually designed that experiment. The step and the all set packages called the Scientific Equipment Bay aboard the Lunar Module their home until landing on the Moon. This bay, it's kind of like a trunk in a car in a way. It was designed so that would allow for easy unloading on the Moon's surface, so it's height with such that the astronauts didn't have to try and bend far down in those big bulky spacesuits to get that things, they could kind of reach and grab it and pull it out. The bay also had boom arms that would help offload materials, particularly the bulky ones that might require both astronauts to work together. Remember, the lunar module would have two astronauts in it and the command module would have the third astronauts still in orbit around the Moon. Uh This was important to have those boom arms because sometimes the lunar module would land in such a way that it wasn't really level on the Moon's surface. You might land at the edge of a little dip, or one of the legs of the lunar module might sink a little further into the dust on the surface, So they wanted to make sure they had systems in place to help with the unloading in case the lunar module wasn't perfectly level. The general procedure for deploying the all set packages was that you would have to find a spot about a hundred meters to the west of the lunar module and make sure that you were not in the shadow the path of the shadow of the lunar module for sunrise, because solar panels would often be part of those experiments, So you needed to have uh unblocked access to sunlight, and you had to find someplace that was, you know, fairly level, which was always the Finding areas on the Moon that met these criteria wasn't always easy. The all set aboard Apollo twelve and the ones on each of the Apollo missions following until Apollo seventeen included some other pieces of equipment. Central to the experiment was a station that acted as a power source. It was kind of like a a little power generator right in the middle, and it had a radio isotope thermoelectric generator. And yet that means that the experiments were powered by the heat generated by radioactive material undergoing decay. Specifically, they were using plutonium to thirty eight in oxide form. The generator could produce seventy watts of direct current electricity, and all of the generators from Apollo twelve to seventeen are on the Moon, with the exception of one, the generator for Apollo thirteen, which was forced to abandon its mission in the wake of an emergency. That generator is somewhere at the bottom of the Pacific Ocean, so they're somewhere in the Pacific Ocean is a radioisotope thermoelectric generator with plutonium to thirty eight in it. Now that meant that all the experiments, and there were many, that these central stations would provide power to actually drew less electricity than what would be needed to power a seventy five what lightbulb, which is pretty incredible. Experiments included stuff like what was uh included in the Apollo eleven package that that was in many of the other ones as well. But the Apollo twelve siometer experiment not only detected when the lunar module crashed into the Moon upon being jettisoned from the Command Service Module, but found that the Moon vibrated or rang like a bell for more than fifty five minutes after that impact. So this was done on purpose the jettison the lunar module. Everyone else was aboard the Command Service module for the return trip home and it was on crash course with the Moon, and it was specifically done so that they could measure the the seismic activity. So why did it vibrate for so long for nearly an hour? Well, according to Dr Ross Taylor, the reason is because the lunar soil is devoid of moisture, which would literally dampen vibrations. Moisture absorbs vibrations, water absorbs them. In fact, when we talk about the Space Shuttle program, I'll talk about how water was used specifically for that purpose. So without moisture, the vibrations could continue much longer than they would on Earth. Other experiments would look into stuff like the heat flow of the Moon. They found that the interior of the Moon is warmer than the surface, so heat flows from the center of the Moon out towards the surface and then dissipates in space. They also had experiments that had magnetoma meters or magnometers if you prefer, but that I'm almost certain that's not the right way to say it. Magneto. They had the x Man magneto or x Man Villain magneto to study the magnetic field of the Moon. They had ion detectors to measure the number and types of ions on the Moon charged particles on the Moon. Mostly those ions were deposited by the solar wind. Other experiments would look for charged particles or cosmic radiation, and the packages on different Apollo missions contained different experiments. Some would be repeated with follow up missions, so you might have an experiment that's on Apollo fourteen that's also on Apollo sixteen. Others were unique to their specific mission. When we come back, i'll talk about an experiment aboard the Apollo seventeen that gave astronauts a bit of a headache when they were deploying it. But first let's take a quick break to thank our sponsor. So one experiment that did not quite go as planned was the Lunar Surface Gravimeter aboard the Apollo seventeen, and scientists at the University of Maryland designed this experiment, and its purpose was to search for evidence of gravity waves. Gravity waves were something that Einstein had predicted in his theories, but no one at that point had found any actual observable evidence of gravity waves, so this device was supposed to look out for that kind of stuff. It was also meant to study the response of the Moon to the Earth's title poll, and it could also supplement data gathered by the various seismometers that were distributed on the Moon's surface. The business end of the experiment, the part that was that at issue was a spring balance that was incredibly sensitive and it had special mass weights attached to it to provide the proper tension on the spring balance. But while designing this particular piece of technology, the team made a mathematical error and the mass was not correct, so it wasn't actually putting enough tension on the spring. The astronauts try to set the experiment to null when calibrating it, and they so setting it to a neutral position, but they foundly couldn't get the meter to register a neutral position, even though they verified the experiment was on a level surface and that the gimbal inside the device could move freely. Only then did NASA realized there was a tiny but sufficiently irritating error. The mass weights were two percent lighter than what they needed to be in order for the device to operate properly. Making things worse, The sensor was adjustable, so you could adjust for error, but it would only adjust to correct for an error of up to one point five cent, and the mass of the weights was a two percent error, so it was greater than what the device could allow for. So they started using some other methods, and one of those methods turned out to be what we in the tech business would tend to call percussive maintenance, which means an astronaut hit the experiment to make it work better. Seriously from a NASA website about this alsup experiment, Schmidt, which is a reference to Apolo seventeen astronaut Harrison Schmidt, wrapped the exposed top plate on the gimble, rocked the experiment in all directions, re leveled the experiment, working the base well against the surface, and verified the sun shade tilt. These actions were taken to free a mass assembly or a sensor beam that was suspected of being caught or bound, but no change was apparent. The problem was at least partly overcome by applying pressure on the beam with the mass changing mechanism beyond the design point, by addition of all included masses so that it contacted the beam much valuable e v A time as extra vehicular activity. About thirty minutes was spent on the attempt, which is kind of a polite way of saying they wasted half an hour trying to get this darn thing to work. All of this is to say that the missions after Apollo Oven we're meant to further our scientific understanding. Numerous experiments would gather information. Some for years after we left the Moon, astronauts would gather samples of the dust and the rocks on the Moon and bring them back. They deployed equipment starting with Apollo fifteen. They also got to tool around on the Moon's surface with the lunar rover. I could do a full episode just about the lunar rover. The Apollo fifteen was the first of Apollo's missions to spend more than just a few hours on the Moon's surface. In fact, the whole mission for Apollo fifteen lasted about twelve days. The CSM pilot spent nearly as much time in lunar orbit as the entire length of the Apollo eight mission. That was the first Apollo eight mission to orbit the Moon. Apollo seventeen, the last of all the missions, launched on December seven, ninety and returned to Earth on December nineteenth, nineteen seventy two. It would be the last time so far that any humans would set foot on the Moon. Now, when I say the last mission, I do mean the last lunar mission. There was one more Apollo mission that I'll talk about a little bit later. Each of these missions were really important, and I could do a full episode about any single one of them. Now, before I transition to talk about the say Us, I thought it would be good to at least talk a little bit about Apollo thirteen and what happened there, because it had the famous malfunction, the subject of many documentaries and films, including the film Apollo thirteen. The mission, which carried astronauts John Swiggert, Fred Hayes, and James Lovell, had a bumpy start. Literally a few minutes after lift off, the astronauts felt a little vibration in the command Service module. The Launch Vehicles center engine shut down two minutes earlier than planned, but the four remaining engines were able to fire for a little bit more than half a minute longer than planned in order to compensate for that early burnout, and the S four B stage had to prepare hell the spacecraft and extra nine seconds as well. But despite all that, everything else seemed to be going really smoothly, so much so that forty six hours into the mission, so nearly two days into the mission, ground control said that the spacecraft was in such good shape and everything was going so smoothly, it was frankly pretty darn boring. Just a little before the fifty six hour of the mission, and oxygen tank in the service module blew up. A second oxygen tank failed, the command module lost electricity, water, and light, and that's when we get the famous phrase, Houston, we've had a problem here, which typically gets paraphrases Houston, we have a problem. The crew would move into the lunar module. Remember with these lunar missions, right after going into orbit, the Command Service module would detach from the S four B and would rendezvous with the S four B two dock with the lunar module on the end of the CSM, So you have the lunar module kind of kind of balanced on the end of the CSM for the rest of the journey to the Moon. So it was already connected to the CSM. So they had this this lunar module where the life support systems were still working. But it wasn't ideal to move everyone in there because the lunar module was meant to support two crew members for less than two days, and instead there would need to be three crew members aboard this lunar module for four days. They also had to cut way back on water consumption because the water was important, not just for them to drink, but also to be used as a cooling system for the various systems aboard the spacecraft. And as a result, because they had to cut so far back on water, they all became severely dehydrated. In fact, collectively the crew would lose thirty one and a half pounds during this mission, almost all of it water weight. So at one point Level had to resort to using the Sun as a navigational star. He had to align the attitude of the lunar module according to the directions he received from ground control, which is pretty phenomenal to think about navigating by the stars when you're out in space. The conditions in that spacecraft were admittedly really tough. The temperature sank down to about thirty eight degrees fahrenheit that's about three degrees celsius, and no one was sure if the command module would power up properly. And the command module was absolutely necessary because that was the spacecraft that was outfitted for re entry. The heat shielding and everything that was on the command module, not the lunar module, so they were still connected at this point. There's a lot of condensation inside the command module. When it became time for them to to transfer back over. That raised a lot of concerns about possible short circuits. When they were powering up the command module, they thought, well, there's a lot of water pooling on the surface. There's probably water underneath the panels as well, which could make a short circuit issue. The astronauts were able to jettison the service module from the command module, and they were able to use the lunar module's propulsion system to pull away from the service module to a safe distance so that it wouldn't collide with the rest of the craft. And then before re entry, they moved back into the command module, strapped themselves in, they jettisoned the lunar module, and they re entered the art atmosphere. So all of that was amazing. It was phenomenal that they were able to achieve this. The parachute deployed as it was supposed to, they splashed down in the South Pacific Ocean on April seventeenth, nineteen seventy, and that the astronauts and ground control were able to solve these critical problems dynamically. They were able to improvise using various systems that were available to them. They didn't have the full suite of capabilities of the spacecraft available. They had to make do, and their challenge was very real and very critical. It could have ended in tragedy. So this is one of the greatest stories of achievement I've ever read about. When you're talking about, you know, figuring out how to make use of what you've got left in order to to make it out of a terrible situation. So keep in mind, like getting to the Moon was an incredible challenge, right, that was insane in some ways, and it involved years of careful planning and calculations. Getting the crew of Apollo thirteen home in one piece meant that scientists and engineers had to work out creative solutions with limited options in just a couple of days. They didn't have months to plan this out. They had to do it in hours, and they did it. The ultimate cause of the explosion was determined to be a problem with the heaters and the oxygen tanks. Uh The command module had been upgraded to provide sixty five volts of direct current power to these heaters. The older design of the command module had only provided twenty eight volts, so this was a step up and voltage, but the problem was the thermostatic switches on the heaters had not been modified to accept that higher voltage. They were still designed for the volts, so the operation of the heaters ended up creating an overheating problem, and that ended up affecting the wire ring surrounding the heaters, and that in turn degraded the teflon installation around the oxygen tanks and made it possible for that explosion to happen. There was one final flight of the Apollo program that was not part of the lunar missions. It didn't get a number like Apollo seventeen, and that was the Apollo Soyuz mission because it involved a rendezvous and docking with a Soviet Soyuz spacecraft, which happened in nineteen So I figure it's time I take a quick trip over to the USSR to talk about the development and technology of the Soyus, a spacecraft that we still depend upon decades later. But before I do that, let's take another quick break to thank our sponsors. If you've listened to my earlier episodes about the Soviet space program, you know it started with the relatively primitive Vostok spacecraft, which had extremely limited capabilities in space, and then you had the vosh Kod spacecraft, which was like a souped up Vostok, and the Voshkod lacked the carrying capacity to supply a crew of two or three cosmonauts with enough air, water, and food to make a trip to the Moon and back feasible. So the Soviet Union needed a new approach. Those earlier spacecraft really meant to try and get the Soviet Union up into space ahead of the Americans, and to do things like simple, relatively simple docking maneuvers. I use the word simple in relative terms because it's actually incredibly complicated. But it was more of a display of the principle of docking than any useful application of it. Anyway. That was all meant as almost like propaganda or political warfare. But to get to the Moon was going to require more than just these quick fixes. Complicating matters, however, was that the lead designer of Soviet spacecraft, Sergei kor Lev, had died on January fourteenth, nineteen sixty six. Kor Lev was the heart and soul of the Soviet space program. He was very much in charge of design, the lead designer, and he had battled with politicians during much of the space race, he was trying to balance the unrealistic deadlines and the low budgets he was being given by politicians with what he could actually accomplish. He died during a surgical procedure, and his successor, Vasily Mission, had to pick up the pieces, and there was still a lot of political pressure to get the Soviets to the Moon before the Americans. But at this point the Soviets were kind of getting a little bit behind the Americans, especially with launch vehicles, which I'll talk about in the next episode. Originally, the plan was to create a spacecraft that could concern list of three large segments, and each segment would be put into orbit on a different launch vehicle or rocket, and then assembled in orbit by cosmonauts. One stage would contain the crew compartment, while the other two would hold the propulsion system and the fuel tankers. But ultimately the Soviets decided that approach was impractical. Obviously, if there was anything that went wrong with any one of those launches, it would mess up the entire thing, so they scaled it back. Originally, they scaled it back as a two part spacecraft, so it would still need two different launch vehicles, and then ultimately they just said this also probably wasn't the best idea and decided to go with a single launch vehicle spacecraft design. So it was a spacecraft that would only need one launch to get into space and that and that it would just be a complete spacecraft top to bottom. The spacecraft had been updated several times, but in general here's how it shakes out. Because the general design of the Sayers space craft has remained consistent, the details are very very different because obviously technology has advanced considerably since the nineteen sixties. The spacecraft is about twenty three feet or seven meters long. Like the Apollo spacecraft, it consists of three modules, right, the Pollo spacecraft has the command module, the service module, and the lunar module. Well, the sail Us has the orbital module. That one is sort of spherical in shape. It's at one end of the spacecraft, the section UH. The the spherical section has the docking mechanism that would allow the soil Us to dock with other spacecraft or space stations. UH. The Russians put up a couple of space stations in orbit and also participated with the International Space Station. So this is the part of the spacecraft that would dock with those facilities. It also has the living facilities for orbital phases of missions. Behind the orbital module, so if you had it standing up on end, it would be the next section down uh is what is called the descent module. It's kind of shaped like a bell and it has a space for three people. It's used during ascent, descent, and landing, so going up, coming down, and actually when it lands on the ground. Behind this section is a cylindrical module called the service module, which has propulsion, life support, electrical systems for the spacecraft. All of those are located in that section. The first Sawyer's mission with a crew ended tragically. It was supposed to involve to spacecraft. You're supposed to have the Saya's one and the Sawyers two, and the two spacecraft were meant to dock in orbit, and this would have happened in April nineteen sixty seven, about a year after the Gemini eight docked with an unmanned a Gina target vehicle. So while the Americans had already shown a successful orbital rendezvous and sucking, this would actually be a an example of two crude spacecraft to spacecrafts with people in them docking together. Uh. The docking system aboard the Soyus relied on an automatic system, so it didn't require pilot and put the way the Gemini and Apollo ones did with the Soya's two grounded because of whether the Soyuz one was to just return to Earth the day after it launched, so the Sayers two never takes off the Soyas one is in orbit and then is supposed to return the next day. But the parachute for the Soyuz one failed to deploy and cosmonaut Colonel Vladimir Komarov died in the resulting crash. Along with a parachute, the Soyus capsule also had a solid fuel rocket that was intended to ignite one meter before landing to help with a soft landing, since like the Volskad, the Soyus was meant to land on solid ground, which would make it a little less ring. Actually, when you watch video or film, I should say, of the Sawyus landing for the h COD landing, it looks pretty scary because there's a big flash just before it lands. It looks like there's an explosion, but in fact that's the solid fuel rocket that at the last second is giving just that little bit of not a little bit, a considerable amount of thrust in order to reduce the impact of landing. Saya's two was an unmanned craft, and saw Us three, which had a crew, were then meant to conduct the first automatic docking procedure in orbit in October ninety eight. The two spacecraft ended up getting really close to each other, but they did not dock. Saw Us four and five would dock in orbit in January nine. The Sawyers five had a full three cosmonaut crew, the Sawyer's four only had a pilot named Vladimir Shat The Love and the two craft would dock together and two crew members from the Sayus five would transfer over to the Soyas four, and both spacecraft returned to Earth safely. Now, while the Soviets planned to use the Sayers to go to the Moon, they were going to rely on a very similar strategy to Apollo, with a lunar landing module that would put the cosmonauts on the Moon and then return them to rendezvous with the Soyas spacecraft in the lunar orbit. The success of the Apollo eleven mission in nineteen sixty nine effectively made the Soviets cancel those plans because it was gonna be very expensive, very difficult. They had not yet completed the design of the lunar module, and it just didn't make sense to keep going after a goal that the Americans had already achieved. But the Soyus lived on just not as a spacecraft to take people to the Moon, but to take people to orbit. Sure, there was one other Soyo's catastrophe that resulted in the death of an entire crew. This one was was pretty scary and and and sad as well. It happened on June ninety one, and it with the Says eleven. The crew had successfully docked with the Salut one. The Saliot one was the very first space station in Earth orbit. This was also the first successful docking procedure. The Sawyers ten, the mission immediately before Sawyer's eleven, was supposed to dock with the Salut one, but had to abandon the mission after some technical malfunctions had prevented docking. So the crew of the Sayers eleven successfully docked with the space station. They board the space station to actually stay on the space station for twenty three days, but then they disconnect because there was a some technical malfunctions that led to an electrical fire aboard the space station, so for safety, the crew got back aboard their spacecraft, the Sawyers eleven. They disconnected from the space station, they piloted the craft to re enter the Earth's atmosphere. Then we're not entirely certain exactly how things went from there, but the capsule landed, parachute deployed. Everything went as planned, but when the retrieval crew got to the capsule, they found that all three crew members inside had died. An investigation concluded that a pressure valve at some point during re entry had failed and that resulted in a loss of cabin pressure, and the crew were not wearing pressurized suits. The Soviets had decided that pressurized suits would not be necessary with the Soyas, and that tragedy ended up changing the minds of the Soviets, and from that point forward, all Soviet crews were required to wear pressure suits during missions. But because the crew was not wearing them in this one, they died from the rapid depressurization. And I alluded to this earlier, but back in nine there was a special joint mission between the United States and the Soviet Union space agencies. The U S would send up an Apollo Command Service module only given the designation of follow. Some people in the media would informally refer to it as Apollo eighteen, but that was not the official designation. In fact, there had been a planned Apollo eighteen mission, but that had already been canceled. The Saya's spacecraft was technically connected to a mission called Saya's nineteen in the Soviet Union. This was the final flight of an Apollo spacecraft, and the docking pilot for the craft was Donald K. Deek Slayton. He was one of the Mercury Seven, one of the original astronauts picked for the Mercury program. He was the one who was grounded for health reasons when they found an irregularity in his heartbeat, and he finally got the clearance to fly again, so he got to go up into space on the final Apollo mission. The Apollo spacecraft was fitted with a special docking mechanism to make it compatible with the Soya's spacecraft, and the two craft docked on July seventeenth, ninety The crews were able to meet with each other. They shook hands with one another, and that symbolically brought the space race to an end, though again you could argue quite convincingly that the moon landing had effectively done that a few years earlier. Both crews were able to return home safely, although on the return trip home the Apollo crew ended up being exposed to an oxidizer that's really toxic. It's nitrogen tetrox side, and there was a switch that had been left open when it should have been closed, according to the crew. The crew member who claimed responsibility said he did he failed to hear the commander called that out on a checklist, and it was his fault that the the switches were not closed. All three were able to recover. They spent a couple of weeks in a hospital in Honolulu, so not the worst place in the world, although I guess if you're in a hospital room, it's not like you're really enjoying the surroundings. So Sayers was not going to go to the Moon, and instead the focus was on the orbital version of the Sayers. Like the seven K O K variation of the craft. There have been a lot of variations of the Soyos over time. Like I said, there's been a lot of updates, upgrades, variants, but the basic design has remained pretty consistent, just with updated subsystems and materials. For several years. After the space Shuttle program was shut shuttered in two thousand eleven, the Sayers was the only spacecraft capable of docking with the International Space Station that would still be in service to this day. It's the only spacecraft that has is allowed to take people to and from the space station. Space x is Dragon two capsule will eventually be able to do that, assuming everything continues to go well for that program, but for right now, the say Us is the only way up or down if you happen to be a human. Today, the space x Dragon capsule is able to dock with the space station, but only for taking stuff up or bringing stuff back down, stuff being non organic, so we're talking like experiments and things. Uh. Space x is still work with NASA to develop a version of that capsule that will be piloted by a crew. Also, the space station has a Saya's spacecraft docked with it all the time that can be used as an emergency lifeboat, so there's an emergency Soyo's capsule attached to the International Space station, and if there is ever an emergency that requires evacuation, the crew can climb into the Saya's capsule and detach and head home. Um NASA and SpaceX do have a contract for up to six crude flights again crude as a manned not you know, c R E W E D, not c R U D, but they have a contract for up to six of those to this space station. Once that Dragon two capsule is cleared for such duties, and then the Sayers will be just a little less special. The current version of the Sayers has the designation Saya's MS. That one entered service in July. It still has the three module design of its predecessors, so it isn't dramatically different, at least in basic construction, but it does have modern power systems, communication systems, navigation systems, computers, all that kind of thing. Everything has been updated from that perspective. There's also a black box like system inside of it that records voice and data during descent phases, so if anything does ever go catastrophically wrong, the retrieval crew could have a chance of retrieving the black box and studying the data to find out what happened and of course, there's no longer a Soviet Union, says MS now falls under the jurisdiction of the Russian Federal Space Agency. So that's a big difference from when the Sayers was first created, and that kind of concludes my overview of the Apollo missions and the Saya's space spacecraft. I am still amazed the spacecraft that was designed in the nineteen sixties is still being used regularly today, although granted it is obviously updated versions of that same spacecraft. So this was a great journey for me. I learned a lot as I looked into this, and in our next episode, we're gonna dive into the scary world of rocket science. We're gonna talk about these launch vehicles that have been used with various spacecraft, and I'm really going to focus on the launch vehicles for the spacecraft that carried people. I'm not gonna look at a whole lot of the like there were. There have been dozens of launch vehicles, some of which have been used only to put things like satellites and stuff up. I say only there's still in an incredible achievement. But I'm going to focus mainly on the ones that were used to put people up into space. That will be our next episode. But if you have a suggestion for a future episode, maybe it has nothing to do with space, send me an email. 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