Speaker 1: Get in touch with technology with tech Stuff from how
Speaker 1: stuff works dot com. Hey there, and welcome to tech Stuff.
Speaker 1: I am your host, Jonathan Strickland. I'm an executive producer
Speaker 1: with how Stuff Works, and I love all things tech.
Speaker 1: And we are, in fact continuing our journey into space,
Speaker 1: or at least the history of space travel. And I
Speaker 1: know we talked a lot about space. We're gonna be
Speaker 1: talking more about space for the next few episodes because
Speaker 1: it's a fascinating topic and I love looking into it
Speaker 1: and there's so much to talk about. The this episode,
Speaker 1: we're going to focus on the later Apollo missions, and
Speaker 1: we will also switch over and talk about the development
Speaker 1: of the Soyuz spacecraft, the Soviet spacecraft that was intended
Speaker 1: to be a competitor to Apollo and is a workhorse
Speaker 1: for space travel now, I mean, it's the only spacecraft
Speaker 1: spoiler alert that will actually bring people back and forth
Speaker 1: between the International Space Station. In upcoming episodes, I'll talk
Speaker 1: more about launch vehicles, which we frequently will refer to
Speaker 1: as rockets, and I will also talk about the Space
Speaker 1: Shuttle program, and then after that we will move on
Speaker 1: to non space related topics. I know it talked a
Speaker 1: lot about it, but I could have gone into even
Speaker 1: more detail about the various spacecraft in their subsystems and
Speaker 1: how they all worked, but I realized that it would
Speaker 1: be over at kill and I didn't want to go
Speaker 1: absolutely nuts. So let's pick up where we left off,
Speaker 1: which was after the return of the Apollo eleven capsule. Now,
Speaker 1: Apollo eleven wasn't just a phenomenal achievement in science, engineering,
Speaker 1: astronaut training, although it was definitely all of those things,
Speaker 1: but it was also effectively the end of the space
Speaker 1: race that had started when the Soviet Union launched sput
Speaker 1: Nick into orbit and put that out as the first
Speaker 1: man made satellite in Earth orbit. The Soviets had won
Speaker 1: those early victories, Sputnik being the first one, but also
Speaker 1: they were the first to put a human into orbit.
Speaker 1: They were the first to put a woman into space,
Speaker 1: but the Americans had managed to be the first two
Speaker 1: docs spacecraft in orbit, and no one else was able
Speaker 1: to put people on the Moon, although the Soviets did
Speaker 1: try to do that too, and I'll talk more about
Speaker 1: those efforts later in this episode. Apollo eleven pretty much
Speaker 1: sealed the deal, and after that success, the space race
Speaker 1: was effectively over. Symbolically, it would not be over for
Speaker 1: a few more years, but the Apollo projects still had
Speaker 1: several more missions before it would end. Apollo eleven was
Speaker 1: not the end of the Apollo program. Apollo twelve was
Speaker 1: the second mission to have a lunar landing. The crew
Speaker 1: would deploy tech called the Apollo Lunar Surface Experiments Package
Speaker 1: or all SEP a l s EP. This was a
Speaker 1: collection of geophysical instruments. Apollo eleven had a more modest
Speaker 1: collection of experiments that they carried. That one was called
Speaker 1: the Early Apollo Surface Experiments Package or a SEP. That
Speaker 1: one had two official experiments and then two additional experiments
Speaker 1: that were not officially part of a SEP. This is
Speaker 1: where I start looking into NASA records and I say,
Speaker 1: what's the difference between officially being part of something and
Speaker 1: not officially being part of something but still going along
Speaker 1: for the ride of being left on the Moon. But
Speaker 1: maybe that's just me getting confused by semantics. NASA on
Speaker 1: Apollo eleven was mostly focused on landing people on the
Speaker 1: freaking Moon and then getting them back home safely, So
Speaker 1: science was sort of a secondary priority, right. It was
Speaker 1: not the highest priority for NASA. For that. For the
Speaker 1: Apollo eleven mission, they had some scientific experiments they wanted
Speaker 1: to include, but mostly they just wanted to concentrate on
Speaker 1: getting people on the Moon and then getting them back
Speaker 1: home safely. The purpose of all SEP was to monitor
Speaker 1: the environment of and a region close to the Apollo
Speaker 1: landing site for at least a year after the end
Speaker 1: of the visit to the Moon. Apollo seventeens version of
Speaker 1: all SEP was designed to to operate for two years,
Speaker 1: and so there The Apollo twelve one was just the
Speaker 1: first all step. All of the other following Apollo missions
Speaker 1: would bring similar packages along. Some of them worked for
Speaker 1: up to eight years before Mission control would shut down
Speaker 1: all remaining all SEP projects on September nineteen seventy seven,
Speaker 1: so some far outlasted their their projected useful lifespan. The
Speaker 1: all SEPs history is pretty darn interesting all in its
Speaker 1: own right. It's it's just the the list of experiments
Speaker 1: is fascinating. The projects started way back in March nineteen
Speaker 1: sixty three, so they knew that the plan was to
Speaker 1: go to the Moon. Kennedy had made the announcement in
Speaker 1: nineteen sixty one, But what could we do once we
Speaker 1: got there, what kind of data would we try to collect?
Speaker 1: And that began a long series of discussions to select
Speaker 1: which experiments would be conducted on the Moon's surface, And
Speaker 1: they had to consider a lot of different factors when
Speaker 1: they were making these choices, not just what was going
Speaker 1: to be the most scientifically interesting, that was obviously one
Speaker 1: of the really important factors, but also what was just
Speaker 1: going to be practical, because the experiments would need to
Speaker 1: be relatively simple in design, because there was no chance
Speaker 1: of sending out a technician to repair a complicated piece
Speaker 1: of equipment once the lunar module would lift off the Moon.
Speaker 1: You know, you can't make a service call and have
Speaker 1: a repairman go to the Moon to fix something. They
Speaker 1: also could not be too heavy, both for the purposes
Speaker 1: of planning out the payload for the launch vehicle, but
Speaker 1: also how you deploy it. How How would you know
Speaker 1: cause the astronauts the how would they actually take it
Speaker 1: out of the lunar module, take it to the rights
Speaker 1: it and set it up it. It was too heavy
Speaker 1: and too complex. Although really heavy wasn't the big problem.
Speaker 1: Bulky was the problem. I mean, on the Moon you
Speaker 1: have one six the Earth's gravity, so it would have
Speaker 1: to be incredibly heavy to be problematic, but bulky was
Speaker 1: an issue that and where the weight was distributed was
Speaker 1: an issue. There were several all steps where astronauts found
Speaker 1: it difficult to carry them, not because necessarily the weight,
Speaker 1: but because there was no convenient way to carry them
Speaker 1: on the Moon's surface. During those discussions, Nassa identified questions
Speaker 1: that scientists felt we should try to answer with these experiments.
Speaker 1: So before designing any equipment or deciding what technology to
Speaker 1: send along, they said, well, what is it exactly do
Speaker 1: we want to learn, and that that will guide us
Speaker 1: into designing these experiments. So those questions included stuff like,
Speaker 1: what is the internal structure of the moon, What is
Speaker 1: the actual geometric shape of the moon? What is the
Speaker 1: present inter internal energy regime sam of the Moon? Where
Speaker 1: where is energy going? Is the Moon shedding energy as
Speaker 1: it absorbing energy? Was the composition of the lunar surface
Speaker 1: wasn't made out of cheese? It turns out no, What
Speaker 1: principal processes were responsible for the present structure of the Moon.
Speaker 1: Why is the Moon the way it is? Was the
Speaker 1: present tectonic pattern and distribution of tectonic activity on the
Speaker 1: Moon are their moon quakes? What are the dominant processes
Speaker 1: of erosion, transport and deposition of material on the lunar surface?
Speaker 1: How does this stuff move around? What volatile substances are
Speaker 1: present on or near the lunar surface? Is there any
Speaker 1: evidence of organic or proto organic molecules on the Moon?
Speaker 1: How old is the Moon? And what is the history
Speaker 1: of dynamic interaction between the Earth and the Moon. A
Speaker 1: follow eleven's ACEP contained a passive seismic experiment package, so
Speaker 1: it would measure essentially moon trimmers, and it had four
Speaker 1: seisometer is that were powered by two solar panels, and
Speaker 1: that would that would study any moon quakes or vibrations
Speaker 1: from meteorite impacts, and it would ultimately record somewhere between
Speaker 1: a hundred and two hundred meteorite impacts during the course
Speaker 1: of its useful lifespan. The second experiment on the ace UP,
Speaker 1: the official experiment, was a lunar dust detector that would
Speaker 1: measure the amount of dust accumulating on the lunar surface
Speaker 1: and would also monitor damage to solar cells caused by
Speaker 1: high energy radiation. Because the Moon does not have the
Speaker 1: same level of protection from radiation as the Earth does.
Speaker 1: Lacking an atmosphere, it doesn't absorb as much of that
Speaker 1: radiation outside of the surface. That is in addition to
Speaker 1: the two official DECEP experiments, they did have two other
Speaker 1: ones I mentioned earlier. Those were a lunar ranging retro reflector,
Speaker 1: which is a fancy way of saying a very reflective surface.
Speaker 1: It was actually an array of one cubes made of
Speaker 1: fused silica, and this reflect the surface was positioned on
Speaker 1: the Moon so that if you had a sufficiently powerful
Speaker 1: laser beam and you knew exactly where that reflective surface was,
Speaker 1: you could aim the laser beam at the surface and
Speaker 1: have it reflect back to the Earth. And if you
Speaker 1: did that with a laser and a sensor, so that
Speaker 1: you've fired the laser and then you had a sensor
Speaker 1: there to detect what the time difference was between firing
Speaker 1: the laser and picking up the reflection, you could get
Speaker 1: very precise measurements of how far away the Moon was,
Speaker 1: to a degree of accuracy of up to eight centimeters,
Speaker 1: which is pretty incredible. You know how close the Moon
Speaker 1: was within eight centimeters. That experiment was operational until June.
Speaker 1: The solar wind composition experiment was the second non ACEP
Speaker 1: experiment deployed by buzz Aldron during Apollo eleven, and it
Speaker 1: used a panel of alunium foil, which was really pretty
Speaker 1: much the same stuff is what you would use to
Speaker 1: wrap up leftovers, and that foil panel was it to
Speaker 1: collect atomic particles that were emitted by the Sun. That
Speaker 1: experiment wasn't left on the Moon, so instead they deployed it.
Speaker 1: They unfolded it and set it up and then left
Speaker 1: it alone for about an hour or so and then
Speaker 1: collected it and stored it in the Lunar Module, and
Speaker 1: they brought it back aboard the Man's Service Module on
Speaker 1: the return trip home, and once they landed, they turned
Speaker 1: over that experiment to a group of scientists from Switzerland.
Speaker 1: It was the group of scientists who had actually designed
Speaker 1: that experiment. The step and the all set packages called
Speaker 1: the Scientific Equipment Bay aboard the Lunar Module their home
Speaker 1: until landing on the Moon. This bay, it's kind of
Speaker 1: like a trunk in a car in a way. It
Speaker 1: was designed so that would allow for easy unloading on
Speaker 1: the Moon's surface, so it's height with such that the
Speaker 1: astronauts didn't have to try and bend far down in
Speaker 1: those big bulky spacesuits to get that things, they could
Speaker 1: kind of reach and grab it and pull it out.
Speaker 1: The bay also had boom arms that would help offload materials,
Speaker 1: particularly the bulky ones that might require both astronauts to
Speaker 1: work together. Remember, the lunar module would have two astronauts
Speaker 1: in it and the command module would have the third
Speaker 1: astronauts still in orbit around the Moon. Uh This was
Speaker 1: important to have those boom arms because sometimes the lunar
Speaker 1: module would land in such a way that it wasn't
Speaker 1: really level on the Moon's surface. You might land at
Speaker 1: the edge of a little dip, or one of the
Speaker 1: legs of the lunar module might sink a little further
Speaker 1: into the dust on the surface, So they wanted to
Speaker 1: make sure they had systems in place to help with
Speaker 1: the unloading in case the lunar module wasn't perfectly level.
Speaker 1: The general procedure for deploying the all set packages was
Speaker 1: that you would have to find a spot about a
Speaker 1: hundred meters to the west of the lunar module and
Speaker 1: make sure that you were not in the shadow the
Speaker 1: path of the shadow of the lunar module for sunrise,
Speaker 1: because solar panels would often be part of those experiments,
Speaker 1: So you needed to have uh unblocked access to sunlight,
Speaker 1: and you had to find someplace that was, you know,
Speaker 1: fairly level, which was always the Finding areas on the
Speaker 1: Moon that met these criteria wasn't always easy. The all
Speaker 1: set aboard Apollo twelve and the ones on each of
Speaker 1: the Apollo missions following until Apollo seventeen included some other
Speaker 1: pieces of equipment. Central to the experiment was a station
Speaker 1: that acted as a power source. It was kind of
Speaker 1: like a a little power generator right in the middle,
Speaker 1: and it had a radio isotope thermoelectric generator. And yet
Speaker 1: that means that the experiments were powered by the heat
Speaker 1: generated by radioactive material undergoing decay. Specifically, they were using
Speaker 1: plutonium to thirty eight in oxide form. The generator could
Speaker 1: produce seventy watts of direct current electricity, and all of
Speaker 1: the generators from Apollo twelve to seventeen are on the Moon,
Speaker 1: with the exception of one, the generator for Apollo thirteen,
Speaker 1: which was forced to abandon its mission in the wake
Speaker 1: of an emergency. That generator is somewhere at the bottom
Speaker 1: of the Pacific Ocean, so they're somewhere in the Pacific
Speaker 1: Ocean is a radioisotope thermoelectric generator with plutonium to thirty
Speaker 1: eight in it. Now that meant that all the experiments,
Speaker 1: and there were many, that these central stations would provide
Speaker 1: power to actually drew less electricity than what would be
Speaker 1: needed to power a seventy five what lightbulb, which is
Speaker 1: pretty incredible. Experiments included stuff like what was uh included
Speaker 1: in the Apollo eleven package that that was in many
Speaker 1: of the other ones as well. But the Apollo twelve
Speaker 1: siometer experiment not only detected when the lunar module crashed
Speaker 1: into the Moon upon being jettisoned from the Command Service Module,
Speaker 1: but found that the Moon vibrated or rang like a
Speaker 1: bell for more than fifty five minutes after that impact.
Speaker 1: So this was done on purpose the jettison the lunar module.
Speaker 1: Everyone else was aboard the Command Service module for the
Speaker 1: return trip home and it was on crash course with
Speaker 1: the Moon, and it was specifically done so that they
Speaker 1: could measure the the seismic activity. So why did it
Speaker 1: vibrate for so long for nearly an hour? Well, according
Speaker 1: to Dr Ross Taylor, the reason is because the lunar
Speaker 1: soil is devoid of moisture, which would literally dampen vibrations.
Speaker 1: Moisture absorbs vibrations, water absorbs them. In fact, when we
Speaker 1: talk about the Space Shuttle program, I'll talk about how
Speaker 1: water was used specifically for that purpose. So without moisture,
Speaker 1: the vibrations could continue much longer than they would on Earth.
Speaker 1: Other experiments would look into stuff like the heat flow
Speaker 1: of the Moon. They found that the interior of the
Speaker 1: Moon is warmer than the surface, so heat flows from
Speaker 1: the center of the Moon out towards the surface and
Speaker 1: then dissipates in space. They also had experiments that had
Speaker 1: magnetoma meters or magnometers if you prefer, but that I'm
Speaker 1: almost certain that's not the right way to say it. Magneto.
Speaker 1: They had the x Man magneto or x Man Villain
Speaker 1: magneto to study the magnetic field of the Moon. They
Speaker 1: had ion detectors to measure the number and types of
Speaker 1: ions on the Moon charged particles on the Moon. Mostly
Speaker 1: those ions were deposited by the solar wind. Other experiments
Speaker 1: would look for charged particles or cosmic radiation, and the
Speaker 1: packages on different Apollo missions contained different experiments. Some would
Speaker 1: be repeated with follow up missions, so you might have
Speaker 1: an experiment that's on Apollo fourteen that's also on Apollo sixteen.
Speaker 1: Others were unique to their specific mission. When we come back,
Speaker 1: i'll talk about an experiment aboard the Apollo seventeen that
Speaker 1: gave astronauts a bit of a headache when they were
Speaker 1: deploying it. But first let's take a quick break to
Speaker 1: thank our sponsor. So one experiment that did not quite
Speaker 1: go as planned was the Lunar Surface Gravimeter aboard the
Speaker 1: Apollo seventeen, and scientists at the University of Maryland designed
Speaker 1: this experiment, and its purpose was to search for evidence
Speaker 1: of gravity waves. Gravity waves were something that Einstein had
Speaker 1: predicted in his theories, but no one at that point
Speaker 1: had found any actual observable evidence of gravity waves, so
Speaker 1: this device was supposed to look out for that kind
Speaker 1: of stuff. It was also meant to study the response
Speaker 1: of the Moon to the Earth's title poll, and it
Speaker 1: could also supplement data gathered by the various seismometers that
Speaker 1: were distributed on the Moon's surface. The business end of
Speaker 1: the experiment, the part that was that at issue was
Speaker 1: a spring balance that was incredibly sensitive and it had
Speaker 1: special mass weights attached to it to provide the proper
Speaker 1: tension on the spring balance. But while designing this particular
Speaker 1: piece of technology, the team made a mathematical error and
Speaker 1: the mass was not correct, so it wasn't actually putting
Speaker 1: enough tension on the spring. The astronauts try to set
Speaker 1: the experiment to null when calibrating it, and they so
Speaker 1: setting it to a neutral position, but they foundly couldn't
Speaker 1: get the meter to register a neutral position, even though
Speaker 1: they verified the experiment was on a level surface and
Speaker 1: that the gimbal inside the device could move freely. Only
Speaker 1: then did NASA realized there was a tiny but sufficiently
Speaker 1: irritating error. The mass weights were two percent lighter than
Speaker 1: what they needed to be in order for the device
Speaker 1: to operate properly. Making things worse, The sensor was adjustable,
Speaker 1: so you could adjust for error, but it would only
Speaker 1: adjust to correct for an error of up to one
Speaker 1: point five cent, and the mass of the weights was
Speaker 1: a two percent error, so it was greater than what
Speaker 1: the device could allow for. So they started using some
Speaker 1: other methods, and one of those methods turned out to
Speaker 1: be what we in the tech business would tend to
Speaker 1: call percussive maintenance, which means an astronaut hit the experiment
Speaker 1: to make it work better. Seriously from a NASA website
Speaker 1: about this alsup experiment, Schmidt, which is a reference to
Speaker 1: Apolo seventeen astronaut Harrison Schmidt, wrapped the exposed top plate
Speaker 1: on the gimble, rocked the experiment in all directions, re
Speaker 1: leveled the experiment, working the base well against the surface,
Speaker 1: and verified the sun shade tilt. These actions were taken
Speaker 1: to free a mass assembly or a sensor beam that
Speaker 1: was suspected of being caught or bound, but no change
Speaker 1: was apparent. The problem was at least partly overcome by
Speaker 1: applying pressure on the beam with the mass changing mechanism
Speaker 1: beyond the design point, by addition of all included masses
Speaker 1: so that it contacted the beam much valuable e v
Speaker 1: A time as extra vehicular activity. About thirty minutes was
Speaker 1: spent on the attempt, which is kind of a polite
Speaker 1: way of saying they wasted half an hour trying to
Speaker 1: get this darn thing to work. All of this is
Speaker 1: to say that the missions after Apollo Oven we're meant
Speaker 1: to further our scientific understanding. Numerous experiments would gather information.
Speaker 1: Some for years after we left the Moon, astronauts would
Speaker 1: gather samples of the dust and the rocks on the
Speaker 1: Moon and bring them back. They deployed equipment starting with
Speaker 1: Apollo fifteen. They also got to tool around on the
Speaker 1: Moon's surface with the lunar rover. I could do a
Speaker 1: full episode just about the lunar rover. The Apollo fifteen
Speaker 1: was the first of Apollo's missions to spend more than
Speaker 1: just a few hours on the Moon's surface. In fact,
Speaker 1: the whole mission for Apollo fifteen lasted about twelve days.
Speaker 1: The CSM pilot spent nearly as much time in lunar
Speaker 1: orbit as the entire length of the Apollo eight mission.
Speaker 1: That was the first Apollo eight mission to orbit the Moon.
Speaker 1: Apollo seventeen, the last of all the missions, launched on
Speaker 1: December seven, ninety and returned to Earth on December nineteenth,
Speaker 1: nineteen seventy two. It would be the last time so
Speaker 1: far that any humans would set foot on the Moon. Now,
Speaker 1: when I say the last mission, I do mean the
Speaker 1: last lunar mission. There was one more Apollo mission that
Speaker 1: I'll talk about a little bit later. Each of these
Speaker 1: missions were really important, and I could do a full
Speaker 1: episode about any single one of them. Now, before I
Speaker 1: transition to talk about the say Us, I thought it
Speaker 1: would be good to at least talk a little bit
Speaker 1: about Apollo thirteen and what happened there, because it had
Speaker 1: the famous malfunction, the subject of many documentaries and films,
Speaker 1: including the film Apollo thirteen. The mission, which carried astronauts
Speaker 1: John Swiggert, Fred Hayes, and James Lovell, had a bumpy start.
Speaker 1: Literally a few minutes after lift off, the astronauts felt
Speaker 1: a little vibration in the command Service module. The Launch
Speaker 1: Vehicles center engine shut down two minutes earlier than planned,
Speaker 1: but the four remaining engines were able to fire for
Speaker 1: a little bit more than half a minute longer than
Speaker 1: planned in order to compensate for that early burnout, and
Speaker 1: the S four B stage had to prepare hell the
Speaker 1: spacecraft and extra nine seconds as well. But despite all that,
Speaker 1: everything else seemed to be going really smoothly, so much
Speaker 1: so that forty six hours into the mission, so nearly
Speaker 1: two days into the mission, ground control said that the
Speaker 1: spacecraft was in such good shape and everything was going
Speaker 1: so smoothly, it was frankly pretty darn boring. Just a
Speaker 1: little before the fifty six hour of the mission, and
Speaker 1: oxygen tank in the service module blew up. A second
Speaker 1: oxygen tank failed, the command module lost electricity, water, and light,
Speaker 1: and that's when we get the famous phrase, Houston, we've
Speaker 1: had a problem here, which typically gets paraphrases Houston, we
Speaker 1: have a problem. The crew would move into the lunar module.
Speaker 1: Remember with these lunar missions, right after going into orbit,
Speaker 1: the Command Service module would detach from the S four
Speaker 1: B and would rendezvous with the S four B two
Speaker 1: dock with the lunar module on the end of the CSM,
Speaker 1: So you have the lunar module kind of kind of
Speaker 1: balanced on the end of the CSM for the rest
Speaker 1: of the journey to the Moon. So it was already
Speaker 1: connected to the CSM. So they had this this lunar
Speaker 1: module where the life support systems were still working. But
Speaker 1: it wasn't ideal to move everyone in there because the
Speaker 1: lunar module was meant to support two crew members for
Speaker 1: less than two days, and instead there would need to
Speaker 1: be three crew members aboard this lunar module for four days.
Speaker 1: They also had to cut way back on water consumption
Speaker 1: because the water was important, not just for them to drink,
Speaker 1: but also to be used as a cooling system for
Speaker 1: the various systems aboard the spacecraft. And as a result,
Speaker 1: because they had to cut so far back on water,
Speaker 1: they all became severely dehydrated. In fact, collectively the crew
Speaker 1: would lose thirty one and a half pounds during this mission,
Speaker 1: almost all of it water weight. So at one point
Speaker 1: Level had to resort to using the Sun as a
Speaker 1: navigational star. He had to align the attitude of the
Speaker 1: lunar module according to the directions he received from ground control,
Speaker 1: which is pretty phenomenal to think about navigating by the
Speaker 1: stars when you're out in space. The conditions in that
Speaker 1: spacecraft were admittedly really tough. The temperature sank down to
Speaker 1: about thirty eight degrees fahrenheit that's about three degrees celsius,
Speaker 1: and no one was sure if the command module would
Speaker 1: power up properly. And the command module was absolutely necessary
Speaker 1: because that was the spacecraft that was outfitted for re entry.
Speaker 1: The heat shielding and everything that was on the command module,
Speaker 1: not the lunar module, so they were still connected at
Speaker 1: this point. There's a lot of condensation inside the command module.
Speaker 1: When it became time for them to to transfer back over.
Speaker 1: That raised a lot of concerns about possible short circuits.
Speaker 1: When they were powering up the command module, they thought, well,
Speaker 1: there's a lot of water pooling on the surface. There's
Speaker 1: probably water underneath the panels as well, which could make
Speaker 1: a short circuit issue. The astronauts were able to jettison
Speaker 1: the service module from the command module, and they were
Speaker 1: able to use the lunar module's propulsion system to pull
Speaker 1: away from the service module to a safe distance so
Speaker 1: that it wouldn't collide with the rest of the craft.
Speaker 1: And then before re entry, they moved back into the
Speaker 1: command module, strapped themselves in, they jettisoned the lunar module,
Speaker 1: and they re entered the art atmosphere. So all of
Speaker 1: that was amazing. It was phenomenal that they were able
Speaker 1: to achieve this. The parachute deployed as it was supposed to,
Speaker 1: they splashed down in the South Pacific Ocean on April seventeenth,
Speaker 1: nineteen seventy, and that the astronauts and ground control were
Speaker 1: able to solve these critical problems dynamically. They were able
Speaker 1: to improvise using various systems that were available to them.
Speaker 1: They didn't have the full suite of capabilities of the
Speaker 1: spacecraft available. They had to make do, and their challenge
Speaker 1: was very real and very critical. It could have ended
Speaker 1: in tragedy. So this is one of the greatest stories
Speaker 1: of achievement I've ever read about. When you're talking about,
Speaker 1: you know, figuring out how to make use of what
Speaker 1: you've got left in order to to make it out
Speaker 1: of a terrible situation. So keep in mind, like getting
Speaker 1: to the Moon was an incredible challenge, right, that was
Speaker 1: insane in some ways, and it involved years of careful
Speaker 1: planning and calculations. Getting the crew of Apollo thirteen home
Speaker 1: in one piece meant that scientists and engineers had to
Speaker 1: work out creative solutions with limited options in just a
Speaker 1: couple of days. They didn't have months to plan this out.
Speaker 1: They had to do it in hours, and they did it.
Speaker 1: The ultimate cause of the explosion was determined to be
Speaker 1: a problem with the heaters and the oxygen tanks. Uh
Speaker 1: The command module had been upgraded to provide sixty five
Speaker 1: volts of direct current power to these heaters. The older
Speaker 1: design of the command module had only provided twenty eight volts,
Speaker 1: so this was a step up and voltage, but the
Speaker 1: problem was the thermostatic switches on the heaters had not
Speaker 1: been modified to accept that higher voltage. They were still
Speaker 1: designed for the volts, so the operation of the heaters
Speaker 1: ended up creating an overheating problem, and that ended up
Speaker 1: affecting the wire ring surrounding the heaters, and that in
Speaker 1: turn degraded the teflon installation around the oxygen tanks and
Speaker 1: made it possible for that explosion to happen. There was
Speaker 1: one final flight of the Apollo program that was not
Speaker 1: part of the lunar missions. It didn't get a number
Speaker 1: like Apollo seventeen, and that was the Apollo Soyuz mission
Speaker 1: because it involved a rendezvous and docking with a Soviet
Speaker 1: Soyuz spacecraft, which happened in nineteen So I figure it's
Speaker 1: time I take a quick trip over to the USSR
Speaker 1: to talk about the development and technology of the Soyus,
Speaker 1: a spacecraft that we still depend upon decades later. But
Speaker 1: before I do that, let's take another quick break to
Speaker 1: thank our sponsors. If you've listened to my earlier episodes
Speaker 1: about the Soviet space program, you know it started with
Speaker 1: the relatively primitive Vostok spacecraft, which had extremely limited capabilities
Speaker 1: in space, and then you had the vosh Kod spacecraft,
Speaker 1: which was like a souped up Vostok, and the Voshkod
Speaker 1: lacked the carrying capacity to supply a crew of two
Speaker 1: or three cosmonauts with enough air, water, and food to
Speaker 1: make a trip to the Moon and back feasible. So
Speaker 1: the Soviet Union needed a new approach. Those earlier spacecraft
Speaker 1: really meant to try and get the Soviet Union up
Speaker 1: into space ahead of the Americans, and to do things
Speaker 1: like simple, relatively simple docking maneuvers. I use the word
Speaker 1: simple in relative terms because it's actually incredibly complicated. But
Speaker 1: it was more of a display of the principle of
Speaker 1: docking than any useful application of it. Anyway. That was
Speaker 1: all meant as almost like propaganda or political warfare. But
Speaker 1: to get to the Moon was going to require more
Speaker 1: than just these quick fixes. Complicating matters, however, was that
Speaker 1: the lead designer of Soviet spacecraft, Sergei kor Lev, had
Speaker 1: died on January fourteenth, nineteen sixty six. Kor Lev was
Speaker 1: the heart and soul of the Soviet space program. He
Speaker 1: was very much in charge of design, the lead designer,
Speaker 1: and he had battled with politicians during much of the
Speaker 1: space race, he was trying to balance the unrealistic deadlines
Speaker 1: and the low budgets he was being given by politicians
Speaker 1: with what he could actually accomplish. He died during a
Speaker 1: surgical procedure, and his successor, Vasily Mission, had to pick
Speaker 1: up the pieces, and there was still a lot of
Speaker 1: political pressure to get the Soviets to the Moon before
Speaker 1: the Americans. But at this point the Soviets were kind
Speaker 1: of getting a little bit behind the Americans, especially with
Speaker 1: launch vehicles, which I'll talk about in the next episode. Originally,
Speaker 1: the plan was to create a spacecraft that could concern
Speaker 1: list of three large segments, and each segment would be
Speaker 1: put into orbit on a different launch vehicle or rocket,
Speaker 1: and then assembled in orbit by cosmonauts. One stage would
Speaker 1: contain the crew compartment, while the other two would hold
Speaker 1: the propulsion system and the fuel tankers. But ultimately the
Speaker 1: Soviets decided that approach was impractical. Obviously, if there was
Speaker 1: anything that went wrong with any one of those launches,
Speaker 1: it would mess up the entire thing, so they scaled
Speaker 1: it back. Originally, they scaled it back as a two
Speaker 1: part spacecraft, so it would still need two different launch vehicles,
Speaker 1: and then ultimately they just said this also probably wasn't
Speaker 1: the best idea and decided to go with a single
Speaker 1: launch vehicle spacecraft design. So it was a spacecraft that
Speaker 1: would only need one launch to get into space and
Speaker 1: that and that it would just be a complete spacecraft
Speaker 1: top to bottom. The spacecraft had been updated several times,
Speaker 1: but in general here's how it shakes out. Because the
Speaker 1: general design of the Sayers space craft has remained consistent,
Speaker 1: the details are very very different because obviously technology has
Speaker 1: advanced considerably since the nineteen sixties. The spacecraft is about
Speaker 1: twenty three feet or seven meters long. Like the Apollo spacecraft,
Speaker 1: it consists of three modules, right, the Pollo spacecraft has
Speaker 1: the command module, the service module, and the lunar module. Well,
Speaker 1: the sail Us has the orbital module. That one is
Speaker 1: sort of spherical in shape. It's at one end of
Speaker 1: the spacecraft, the section UH. The the spherical section has
Speaker 1: the docking mechanism that would allow the soil Us to
Speaker 1: dock with other spacecraft or space stations. UH. The Russians
Speaker 1: put up a couple of space stations in orbit and
Speaker 1: also participated with the International Space Station. So this is
Speaker 1: the part of the spacecraft that would dock with those facilities.
Speaker 1: It also has the living facilities for orbital phases of missions.
Speaker 1: Behind the orbital module, so if you had it standing
Speaker 1: up on end, it would be the next section down
Speaker 1: uh is what is called the descent module. It's kind
Speaker 1: of shaped like a bell and it has a space
Speaker 1: for three people. It's used during ascent, descent, and landing,
Speaker 1: so going up, coming down, and actually when it lands
Speaker 1: on the ground. Behind this section is a cylindrical module
Speaker 1: called the service module, which has propulsion, life support, electrical
Speaker 1: systems for the spacecraft. All of those are located in
Speaker 1: that section. The first Sawyer's mission with a crew ended tragically.
Speaker 1: It was supposed to involve to spacecraft. You're supposed to
Speaker 1: have the Saya's one and the Sawyers two, and the
Speaker 1: two spacecraft were meant to dock in orbit, and this
Speaker 1: would have happened in April nineteen sixty seven, about a
Speaker 1: year after the Gemini eight docked with an unmanned a
Speaker 1: Gina target vehicle. So while the Americans had already shown
Speaker 1: a successful orbital rendezvous and sucking, this would actually be
Speaker 1: a an example of two crude spacecraft to spacecrafts with
Speaker 1: people in them docking together. Uh. The docking system aboard
Speaker 1: the Soyus relied on an automatic system, so it didn't
Speaker 1: require pilot and put the way the Gemini and Apollo
Speaker 1: ones did with the Soya's two grounded because of whether
Speaker 1: the Soyuz one was to just return to Earth the
Speaker 1: day after it launched, so the Sayers two never takes
Speaker 1: off the Soyas one is in orbit and then is
Speaker 1: supposed to return the next day. But the parachute for
Speaker 1: the Soyuz one failed to deploy and cosmonaut Colonel Vladimir
Speaker 1: Komarov died in the resulting crash. Along with a parachute,
Speaker 1: the Soyus capsule also had a solid fuel rocket that
Speaker 1: was intended to ignite one meter before landing to help
Speaker 1: with a soft landing, since like the Volskad, the Soyus
Speaker 1: was meant to land on solid ground, which would make
Speaker 1: it a little less ring. Actually, when you watch video
Speaker 1: or film, I should say, of the Sawyus landing for
Speaker 1: the h COD landing, it looks pretty scary because there's
Speaker 1: a big flash just before it lands. It looks like
Speaker 1: there's an explosion, but in fact that's the solid fuel
Speaker 1: rocket that at the last second is giving just that
Speaker 1: little bit of not a little bit, a considerable amount
Speaker 1: of thrust in order to reduce the impact of landing.
Speaker 1: Saya's two was an unmanned craft, and saw Us three,
Speaker 1: which had a crew, were then meant to conduct the
Speaker 1: first automatic docking procedure in orbit in October ninety eight.
Speaker 1: The two spacecraft ended up getting really close to each other,
Speaker 1: but they did not dock. Saw Us four and five
Speaker 1: would dock in orbit in January nine. The Sawyers five
Speaker 1: had a full three cosmonaut crew, the Sawyer's four only
Speaker 1: had a pilot named Vladimir Shat The Love and the
Speaker 1: two craft would dock together and two crew members from
Speaker 1: the Sayus five would transfer over to the Soyas four,
Speaker 1: and both spacecraft returned to Earth safely. Now, while the
Speaker 1: Soviets planned to use the Sayers to go to the Moon,
Speaker 1: they were going to rely on a very similar strategy
Speaker 1: to Apollo, with a lunar landing module that would put
Speaker 1: the cosmonauts on the Moon and then return them to
Speaker 1: rendezvous with the Soyas spacecraft in the lunar orbit. The
Speaker 1: success of the Apollo eleven mission in nineteen sixty nine
Speaker 1: effectively made the Soviets cancel those plans because it was
Speaker 1: gonna be very expensive, very difficult. They had not yet
Speaker 1: completed the design of the lunar module, and it just
Speaker 1: didn't make sense to keep going after a goal that
Speaker 1: the Americans had already achieved. But the Soyus lived on
Speaker 1: just not as a spacecraft to take people to the Moon,
Speaker 1: but to take people to orbit. Sure, there was one
Speaker 1: other Soyo's catastrophe that resulted in the death of an
Speaker 1: entire crew. This one was was pretty scary and and
Speaker 1: and sad as well. It happened on June ninety one,
Speaker 1: and it with the Says eleven. The crew had successfully
Speaker 1: docked with the Salut one. The Saliot one was the
Speaker 1: very first space station in Earth orbit. This was also
Speaker 1: the first successful docking procedure. The Sawyers ten, the mission
Speaker 1: immediately before Sawyer's eleven, was supposed to dock with the
Speaker 1: Salut one, but had to abandon the mission after some
Speaker 1: technical malfunctions had prevented docking. So the crew of the
Speaker 1: Sayers eleven successfully docked with the space station. They board
Speaker 1: the space station to actually stay on the space station
Speaker 1: for twenty three days, but then they disconnect because there
Speaker 1: was a some technical malfunctions that led to an electrical
Speaker 1: fire aboard the space station, so for safety, the crew
Speaker 1: got back aboard their spacecraft, the Sawyers eleven. They disconnected
Speaker 1: from the space station, they piloted the craft to re
Speaker 1: enter the Earth's atmosphere. Then we're not entirely certain exactly
Speaker 1: how things went from there, but the capsule landed, parachute deployed.
Speaker 1: Everything went as planned, but when the retrieval crew got
Speaker 1: to the capsule, they found that all three crew members
Speaker 1: inside had died. An investigation concluded that a pressure valve
Speaker 1: at some point during re entry had failed and that
Speaker 1: resulted in a loss of cabin pressure, and the crew
Speaker 1: were not wearing pressurized suits. The Soviets had decided that
Speaker 1: pressurized suits would not be necessary with the Soyas, and
Speaker 1: that tragedy ended up changing the minds of the Soviets,
Speaker 1: and from that point forward, all Soviet crews were required
Speaker 1: to wear pressure suits during missions. But because the crew
Speaker 1: was not wearing them in this one, they died from
Speaker 1: the rapid depressurization. And I alluded to this earlier, but
Speaker 1: back in nine there was a special joint mission between
Speaker 1: the United States and the Soviet Union space agencies. The
Speaker 1: U S would send up an Apollo Command Service module
Speaker 1: only given the designation of follow. Some people in the
Speaker 1: media would informally refer to it as Apollo eighteen, but
Speaker 1: that was not the official designation. In fact, there had
Speaker 1: been a planned Apollo eighteen mission, but that had already
Speaker 1: been canceled. The Saya's spacecraft was technically connected to a
Speaker 1: mission called Saya's nineteen in the Soviet Union. This was
Speaker 1: the final flight of an Apollo spacecraft, and the docking
Speaker 1: pilot for the craft was Donald K. Deek Slayton. He
Speaker 1: was one of the Mercury Seven, one of the original
Speaker 1: astronauts picked for the Mercury program. He was the one
Speaker 1: who was grounded for health reasons when they found an
Speaker 1: irregularity in his heartbeat, and he finally got the clearance
Speaker 1: to fly again, so he got to go up into
Speaker 1: space on the final Apollo mission. The Apollo spacecraft was
Speaker 1: fitted with a special docking mechanism to make it compatible
Speaker 1: with the Soya's spacecraft, and the two craft docked on
Speaker 1: July seventeenth, ninety The crews were able to meet with
Speaker 1: each other. They shook hands with one another, and that
Speaker 1: symbolically brought the space race to an end, though again
Speaker 1: you could argue quite convincingly that the moon landing had
Speaker 1: effectively done that a few years earlier. Both crews were
Speaker 1: able to return home safely, although on the return trip
Speaker 1: home the Apollo crew ended up being exposed to an
Speaker 1: oxidizer that's really toxic. It's nitrogen tetrox side, and there
Speaker 1: was a switch that had been left open when it
Speaker 1: should have been closed, according to the crew. The crew
Speaker 1: member who claimed responsibility said he did he failed to
Speaker 1: hear the commander called that out on a checklist, and
Speaker 1: it was his fault that the the switches were not closed.
Speaker 1: All three were able to recover. They spent a couple
Speaker 1: of weeks in a hospital in Honolulu, so not the
Speaker 1: worst place in the world, although I guess if you're
Speaker 1: in a hospital room, it's not like you're really enjoying
Speaker 1: the surroundings. So Sayers was not going to go to
Speaker 1: the Moon, and instead the focus was on the orbital
Speaker 1: version of the Sayers. Like the seven K O K
Speaker 1: variation of the craft. There have been a lot of
Speaker 1: variations of the Soyos over time. Like I said, there's
Speaker 1: been a lot of updates, upgrades, variants, but the basic
Speaker 1: design has remained pretty consistent, just with updated subsystems and materials.
Speaker 1: For several years. After the space Shuttle program was shut
Speaker 1: shuttered in two thousand eleven, the Sayers was the only
Speaker 1: spacecraft capable of docking with the International Space Station that
Speaker 1: would still be in service to this day. It's the
Speaker 1: only spacecraft that has is allowed to take people to
Speaker 1: and from the space station. Space x is Dragon two
Speaker 1: capsule will eventually be able to do that, assuming everything
Speaker 1: continues to go well for that program, but for right now,
Speaker 1: the say Us is the only way up or down
Speaker 1: if you happen to be a human. Today, the space
Speaker 1: x Dragon capsule is able to dock with the space station,
Speaker 1: but only for taking stuff up or bringing stuff back down,
Speaker 1: stuff being non organic, so we're talking like experiments and things. Uh.
Speaker 1: Space x is still work with NASA to develop a
Speaker 1: version of that capsule that will be piloted by a crew. Also,
Speaker 1: the space station has a Saya's spacecraft docked with it
Speaker 1: all the time that can be used as an emergency lifeboat,
Speaker 1: so there's an emergency Soyo's capsule attached to the International
Speaker 1: Space station, and if there is ever an emergency that
Speaker 1: requires evacuation, the crew can climb into the Saya's capsule
Speaker 1: and detach and head home. Um NASA and SpaceX do
Speaker 1: have a contract for up to six crude flights again
Speaker 1: crude as a manned not you know, c R E
Speaker 1: W E D, not c R U D, but they
Speaker 1: have a contract for up to six of those to
Speaker 1: this space station. Once that Dragon two capsule is cleared
Speaker 1: for such duties, and then the Sayers will be just
Speaker 1: a little less special. The current version of the Sayers
Speaker 1: has the designation Saya's MS. That one entered service in July.
Speaker 1: It still has the three module design of its predecessors,
Speaker 1: so it isn't dramatically different, at least in basic construction,
Speaker 1: but it does have modern power systems, communication systems, navigation systems, computers,
Speaker 1: all that kind of thing. Everything has been updated from
Speaker 1: that perspective. There's also a black box like system inside
Speaker 1: of it that records voice and data during descent phases,
Speaker 1: so if anything does ever go catastrophically wrong, the retrieval
Speaker 1: crew could have a chance of retrieving the black box
Speaker 1: and studying the data to find out what happened and
Speaker 1: of course, there's no longer a Soviet Union, says MS
Speaker 1: now falls under the jurisdiction of the Russian Federal Space Agency.
Speaker 1: So that's a big difference from when the Sayers was
Speaker 1: first created, and that kind of concludes my overview of
Speaker 1: the Apollo missions and the Saya's space spacecraft. I am
Speaker 1: still amazed the spacecraft that was designed in the nineteen
Speaker 1: sixties is still being used regularly today, although granted it
Speaker 1: is obviously updated versions of that same spacecraft. So this
Speaker 1: was a great journey for me. I learned a lot
Speaker 1: as I looked into this, and in our next episode,
Speaker 1: we're gonna dive into the scary world of rocket science.
Speaker 1: We're gonna talk about these launch vehicles that have been
Speaker 1: used with various spacecraft, and I'm really going to focus
Speaker 1: on the launch vehicles for the spacecraft that carried people.
Speaker 1: I'm not gonna look at a whole lot of the
Speaker 1: like there were. There have been dozens of launch vehicles,
Speaker 1: some of which have been used only to put things
Speaker 1: like satellites and stuff up. I say only there's still
Speaker 1: in an incredible achievement. But I'm going to focus mainly
Speaker 1: on the ones that were used to put people up
Speaker 1: into space. That will be our next episode. But if
Speaker 1: you have a suggestion for a future episode, maybe it
Speaker 1: has nothing to do with space, send me an email.
Speaker 1: I've been getting some great messages lately. You guys are
Speaker 1: killing it. Keep up the great work. The email address
Speaker 1: is tech Stuff at how stuff works dot com. Also,
Speaker 1: don't forget, we now have a merchandise door. Is that
Speaker 1: t public dot com slash tech Stuff? That's t e
Speaker 1: public dot com slash tech Stuff. You can find all
Speaker 1: sorts of stuff. We're talking about shirts, stickers, phone cases
Speaker 1: with different designs. Go check out the tech Stuff logo
Speaker 1: designs on their. Guys. Just imagine you could whip out
Speaker 1: your smartphone and your protective case with the tech stuff
Speaker 1: logo and everyone's gonna know how cool you are. So
Speaker 1: check that out. Don't forget. You can also get in
Speaker 1: touch with me on Facebook or Twitter with the handled
Speaker 1: text Stuff hs W and follow us on Instagram and
Speaker 1: I will talk to you again really soon for more
Speaker 1: on this and thousands of other topics. Because it how
Speaker 1: stuff works dot com.