The Apollo Missions

United States during the Space Race. I talked about the first people in space, the first spacewalk, and the development of spacecraft like the Gemini or Jiminy if you prefer, which could hold more than one astronaut at a time. We're going to continue today by looking to the successor to the Gemini program, that would be the Apollo program.

But before I can do that, I'm going to talk a little bit more about Gemini because there's some points that I kind of covered at the end of the last episode, but I feel we need to go into

more detailed to understand why they were so warnant. In the next episode, I will actually finish up about the Apollo program because it turns out a lot happened during that, and then we're going to transition to talk about the Soyuz spacecraft that would be the Russian successor in the Soviet program, and it's a spacecraft that is still being used today decades later. So we'll get into that in

the next episode. Now, part of the reason I had to cover the whole space race in this way and this kind of jumping around way, is that these various projects were not all linear. It's not like Mercury was planned, started and ended, and then Jim and I began, and then Jim and I went through and ended, and then Apollo began. In fact, technically the Apollo mission began before GEM and I did. GEM and I ended up being necessary in order to test certain technologies and procedures and

processes that would make Apollo possible. It was a a bridge between en Mercury and Apollo. It was decided after the fact that we had made this commitment that we were going to send astronauts to the Moon now. Project Mercury's research and development phase started back in nineteen fifty eight, and the operational phase didn't begin until nineteen sixty one,

and the project essentially concluded in nineteen sixty three. Before the first Mercury spacecraft had even launched, NASA was already talking about what it would take to design, build, and launch spacecraft capable of holding three astronauts and sending them to the Moon and bringing them back. This hypothetical craft would need to be able to do lots of different stuff, and it would become the Apollo program. That enormous leap would be a huge, huge jump off of the Mercury spacecraft.

Remember that was a one astronauts spacecraft. It was really just designed for orbital flights around the Earth, and it was largely a testing ground for technologies and also just to to see what we could learn based upon that sort of limited use of space travel to go around the Earth. Not like that wasn't a difficult enough thing to do already, but it was still a small step toward what people had eventually planned for the United States

space program. So the Mercury was a phenomenal achievement. I don't want to downplay that. It was amazing that we could build a spacecraft that could withstand the rigors of space, send someone up there and bring that person back down safely. And also there was no need for the astronaut to eject from the Mercury capsule. Remember the Soviet cosmonauts on the Vostok spacecraft in the Soviet program, they had to eject on re entry. They could not just ride the

vast stalk down to the surface. They would have probably been rattled to death if they had done that. But the mercury was also extremely limited right it had at orbital limitation. It wasn't meant to do anything beyond orbit the Earth, and it lacked the capabilities to do the stuff the Apollo spacecraft would have to do in order to have a successful mission. So that's why the Gemini

program would slip in between the two. And it also provided a training ground for astronauts to learn how to endure longer space flights, because that was gonna be an issue. If you wanted to go all the way to the Moon and back, it was going to take several days, not just a few hours or maybe one day of orbit. They also learned how to conduct spacewalks, how to navigate and pilot a spacecraft in space. That was a big deal, and also they needed to learn how to rendezvous and

doc with other spacecraft. Now I mentioned in the previous episode that the first mission to have two spacecraft dock in orbit was in a Gemini mission. It was Gemini eight, which was piloted by Neil Armstrong and David Scott, and I also mentioned that there was an emergency in that particular mission and where after the two spacecraft had docked

there was a problem. But I wanted to talk a little bit more about the actual docking process, just to kind of give across how complicated this is and how much precision is required to make it work. So the Gemini spacecraft docked with a vehicle that existed only for the purpose of testing the docking technology and the procedures. It was called an a Gina Target vehicle, and the official designation was g A t V five zero zero

three for for the Gemini eight. This spacecraft was seven point nine three ms long that's about twenty six ft, and had a diameter of one point five two ms or just a hair under five feet in diameter, and had its own flight control electronics at its own guidance systems, propulsion system, electrical power. All of this was necessary so NASA can make certain the spacecraft was in the proper

orbit and orientation for a rendezvous and docking mission. On one end of this target vehicle there was a cone shaped section, so this was the part where the Gemini spacecraft would dock into. It's kind of a a cone area and it conformed to the shape of the nose of the Gemini spacecraft. So you bring the Gemini spacecraft in nose first, and it would dock into this cone shaped section of the target vehicle. And then once you're in place, docking latches would close to secure the two

spacecraft together. The target vehicle could then engage its propulsion systems after it docked, and that would mean that NASA back on ground could change the orbit of the pair of docked spacecraft using the target vehicle's engines. So imagine for a moment how monumentally challenging this is to do. And this is going to require us to talk about some math. Now, it's pretty simple math when you get

down to it. The formula is not terribly complicated, but it is mass that has to do with some pretty wicked numbers. First, the two spacecraft are in orbit around the Earth. So to stay in orbit, to to get into an orbit around a celestial body, that satellite, that

spacecraft has to maintain orbital velocity. This is the velocity required to keep a steady orbit at a specific distance away from a celestial body and that amount that that's that velocity, that speed if you prefer which is less precise, but we'll go with speed. It's very common term. The speed depends upon the mass of the body you're orbiting, so in this case it would be the Earth uh. And also the radius that or the distance between you

and the center of that mass. There's also a gravitational constant that you have to factor into this, that's universal. The universal gravitational constant is the same number wherever you are. UH. In case you're curious, the universal constant gravitational constant is six point six seven three times ten to the power of negative eleven Newton meter squared per kilogram squared. And that number is what you would multiply by the mass of the body you're orbiting, so the mass of the Earth.

Then you would divide that product. You know, you multiply those two numbers together, you get a product. You divide that by the distance between you and the center of the Earth. Then once you take that solution, you would take the square root of that and that would give you your orbital velocity, how fast you need to go in order to maintain your orbit. So if you were trying to orbit the Earth at four kilometers above the surface,

how fast would you need to go? What would your orbital speed need to be so that you would maintain that orbital distance from the Earth. Well, the Earth has a mass of five point nine eight times ten to the twenty four power rams and the gravitational constant, as I mentioned earlier, is that six point six seven three times ten to the power of minus eleven. So if we multiply both of those together, that gives us the product of three point nine nine zero four five four

times ten to the four power. That's our product. Okay, so that's the top of our fraction. Right, let's talk about distance. That's the bottom of our fraction. The Earth's radius is six thousand, three kilometers and your four hundred kilometers higher than that because you're four kilometers above the surface. So you have to take both of those numbers and add them together. Let's also convert it to meters. It will make life easier for us in the long run.

That would give us six million, seven hundred eighty thousand meters. That's the distance between you and the center of the Earth. So that's the bottom of our fraction. We divide our earlier product by this number six million, seven hundred eighty thousand. That gives us the very easy to describe number fifty eight million, eight hundred fifty six thousand, two hundred fifty three point six eight seven three. So that's our our answer there. Then we have to take the square root

of that. Taking the square root of that will give us our velocity. If you take the square root and then you have to round up a little bit, it is approximately seven thousand, six hundred seventy two meters per second, So that's the speed you have to maintain to stay in orbit. That's about four point seven seven miles per second, or seventeen thousand, one hundred seventy two miles per hour. So you've got these two spacecraft traveling at four hundred

kilometers above the surface of the Earth. They're traveling at seventeen thousand, one seventy two miles per hour each. Then you want the two of them to meet up in space and dock with one another, which is terrifying. Right. Also, because you're in space, you're in an environment where if you damage your spacecraft it was it's gonna lead to catastrophic decompression. And you're going to have a really bad time of it. You can't afford to make any mistakes.

You have to have this be very, very precise. The equation also tells us by the way that the closer you are to the Earth, the faster you have to travel in order to maintain orbital velocity. That also means that you'll make several full orbits around the Earth within a single Earth day. You're actually you're going around the Earth faster than the Earth's rotation. But the further out you go, the less velocity you need to maintain your orbit.

So if you're pretty far out there, and we're talking miles above the Earth, your orbital speed only needs to be about six thousand eighty miles per hour, significantly less than that seventeen thousand I was talking about earlier. If it's at that speed, you will make one full orbit of the Earth every twenty four hours, which means that if you are located above the equator, you'll essentially be

in a locked position relative to the Earth. You will stay above that that point on the Earth, and you will maintain your position relative to the Earth because the Earth and you are traveling at a way where the Earth's rotation and your orbit are staying in alignment the entire time. That's where you get into that geo stationary orbit.

If you have a satellite geo stationary orbit, it is at this very high orbit and it's essentially somewhere near the equator, so it can maintain its relative position above the Earth. By the way, you need that velocity to be right, because if you go slower than orbital velocity, your orbit will gradually decay and you will get drawn towards the planet, which will ultimately mean re entering the

Art's atmosphere and landing or burning up. If you're going faster than orbital velocity, you will gradually move further out from the planet, assuming that you are capable of keeping that that speed, and if you're going fast enough, you'll attain escape velocity from the planet's gravitational pull and you'll just go off into space somewhere. Now, the reason I even cover this so thoroughly is that the Apollo missions

and the soil Use spacecraft both have docking capabilities. In fact, for Apollo's lunar missions, docking was absolutely necessary, as it was how the lunar landing module was able to rendezvous and reconnect with the rest of the spacecraft, which would remain in lunar orbit. Now, when I come back, i'll talk more about the Apollo program and the amazing achievement of putting astronauts on the Moon. But first let's take

a quick break and thank our sponsor. The Apollo spacecraft, when you're looking at the actual lunar missions, was essentially a three part craft. Only one of those parts, called the Command module, was designed to land back on Earth in a retrievable fashion. The three parts were the Command module that was the section with all the flight controls. That's where the crew would sit during takeoff and normal

operations and landing. Then there was the Service module. This was kind of like the the big container that had all the propulsion systems and spacecraft support systems, had an engine on it for firing. Those two parts of the spacecraft would remain together for most of the mission, and the third segment was the lunar module, which would have to dock with the Command Service Module or cs UM. They would often group these two modules together and just

call them CSM. The lunar module would have to dock with CSM in space, then separate once it was in lunar orbit land on the Moon, lift off from the Moon, rendezvous with the CSM REDOC, and then the astronauts would move back over to the c s M, whereupon they would jettison the lunar module and travel back home. Thus, that's why that's why the Gemini docking procedure was so important. It was sort of a proof that this strategy was going to work because the strategy of getting astronauts on

and off the Moon depended upon that capability. The Command Service Module UH would pretty much stay connected up until you get to where it was time to re enter the r atmosphere, whereupon the command module would jettison the service module and it would just become that sort of cone shaped spacecraft that we're all familiar with. The heat shield was on the bottom of that section, and that's what would point toward the Earth while the spacecraft would

reenter Ther's atmosphere. Now, the three modules attached to an upper stage of a rocket in a special housing. The stage was called the S four B. The CSM would separate from this special casing that was attached to the S four B, and the lunar module would still be inside that casing, which then would kind of have the walls flange outward. People referred to it as looking like an angry alligator, although it was an angry alligator with

four jaws, not too which is really terrifying. And then the CSM, the Command Service module, could dock with a lunar module which would then detach from the S four B, and then you would have your Apollos spacecraft that could continue on toward the Moon, whereas the S four B would then inject itself into a trajectory, either a solar trajectory for the early missions or later on a lunar trajectory where the Annassa was really testing impact spacecraft impact

with the Moon. They had a lot of UH sensors aboard the S four B that would give them data about impacting it with the Moon. They just made sure that obviously that the S four B was going to hit a part of the Moon that was nowhere close to where the astronauts were going to be. Before there were any astronauts in any Apollo spacecraft, NASA held a series of unscrewed missions. They were called the Apollo Saturn

uncrewed missions. The first three of these carried a designation that began with a S. So the first of those was the A S two oh one, the second was called A S two o two, and the third a S two oh three, although I should point out A S two oh three launched before a S two oh two. Uh, they were close together in launch, but two or three technically went up first. They also were meant to test different things. It wasn't like NASA was just repeating the same test over and over. Each test had its own

mission objectives. They were designed to test the operation of the launch vehicles and make sure that they could launch the load of an Apollo spacecraft into orbit. You know, make sure that the thing you have, the rocket you have built, can actually carry the payloads safely up into space. That's a big deal. And in an upcoming episode, I'm going to focus more on rockets and launch vehicles and talk about the science and technology behind those, So we'll

save all of that discussion for later. The mission objective for the first of these, the A S two oh one, is described by NASA like this. This is a quote from their website. Achieved structural integrity and compatibility of launch vehicle as well as launch loads demonstrated separation of first and second stages of Saturn l e S and boost protective cover from the Command and Service Module or CSM.

Demonstrated separation of CSM from Instrument Unit, spacecraft and Lunar Module adapter, as well as CM separation from the s M. Verified operations of Saturn propulsion guidance and control and electrical subsystems partially achieved verification of spacecraft subsystems and heat shield for re entry from Low Earth orbit due to loss of data during maximum heating. Demonstrated operation of mission support facilities.

So what does that mean, Well, it meant that they were testing the launch vehicle making sure that the rocket was separating properly in order to get the spacecraft into space. So the rocket had several sections and each section needed to separate cleanly from the others in order for this process to work. They also made sure that the command module and the service module would separate properly because the command module had to be on its own in order

for re entry that happened safely. And then they were testing out some of the spacecraft subsystems. But as they mentioned in the mission over objective and mission Briefing, UH This did not go without a hitch. There was a loss of some data due to heating, so they didn't It's it's not necessarily the case that the systems didn't work, but we didn't have the data to know one way or the other because of this heating issue. AS two A one launched on February nineteen sixty six, and it

was a short mission. It lasted only thirty seven minutes from liftoff to touchdown. The mission had several technical malfunctions, including three serious ones, which is why engineers do unmanned tests in the first place, to identify and solve those problems before human lives are ever at stake. This was a suborbital mission. It did not go into orbit. It went up to a very high altitude, but it was

a sub orbital test. The following mission, on August nineteen sixty six, this is a S two oh two, was the first to test the fuel cell power system that would power the spacecraft. Now I've talked about fuel cells in other episodes. I've got another episode I have planned where I'm going to talk more about fuel cells, so

I'm not going to go into it here. It's a really interesting technology, but we'll cover it more in a future episode, and if you really want to learn more, you can look at the tech Stuff archives and find an old episode where we talk about fuel cells. Like the a S two oh one mission, the two oh two was also suborbital. This one lasted ninety three minutes from liftoff to touchdown, and it proved the design of the heat shield for the spacecraft worked as was intended.

The two oh three unmanned mission, the one that took place in between two oh one and two or three, was actually an orbital mission. It went all the way up into orbit. So you might say, well, why is this one designated two oh three when one it happened before to oh two, and why did it go into orbit when two o two didn't. Well, two oh three did not carry a command module or a service module

or a lunar module. The main purpose of two oh three was to test the propulsion system that would boost an Apollo spacecraft from Earth orbit to insert it into a learned lunar orbit. So the S four B was a very important component here, but the actual spacecraft was not included in this. And now to get to what was originally designated as a S two oh four. This is one of the tragedies of the U S space program. There have been a few, and this was a pretty

This was a terrible one. It wasn't a pretty bad one. This was a terrible one. It happened on January nine. This was supposed to be the first manned mission on an Apollo spacecraft, and it was intended to be a suborbital flight, so it wasn't meant to go into Earth orbit. It was meant to go up to space and come

right back down again. I was supposed to test Apollos systems with actual human beings aboard, and the astronauts aboard were Virgil Grisom, he had been one of the original Mercury seven astronauts, Edward White, who was the first American to walk in space during the Gemini four mission, and Roger Chaffee, who had served on the ground on various missions, but this was his first chance to fly in a

mission as an astronaut. They were inside the command module when during a pre flight test, a fire swept through the module and all three astronauts lost their lives. This was a terrible tragedy. NASA immediately started an investigation into the accident and suspended all crude missions for more than a year. As a result, they did continue working on uncrude tests, testing the lunar module, in particular, by they

were absolutely concerned. They wanted to make absolutely certain that they eliminated the possibility as best they could of such an accident happening again, and it was a terrible loss. Later in nineteen sixty seven, Dr. Georgie Muller, who was the Associate Administrator for Manned space Flight at NASA, announced that the mission was retroactively going to be named the Apollo one, so it's no longer a S two O four. It was Apollo one. The next unscrewed mission was Apollo four,

and that happened on November nine, nineteen sixty seven. Also at this time, I think it's interesting to point out there were no missions that ever received the designation Apollo two or Apollo three, so there's no Apolo to No Apollo three went from Apollo one to Apollo four, and Apollo four carried an unscrewed Apollo spacecraft, so no astronauts were aboard. This was an orbital test that lasted about nine and a half hours. The spacecraft enter a translunar

trajectory before returning to Earth. Apollo five was another unscrewed mission. This one carried a lunar module as a payload, so it was to test the module's propulsion systems in space.

Apollo six carried a command and Service module as well as a Lunar Module Test Article or l t A. So on casual glance, this looked like the lunar modules that astronauts would later use to go to the Moon's surface, but instead of carrying all the life support systems and the related systems that the astronauts would absolutely need, the test article carried systems that were measuring the dynamic behavior of the module during launch to make sure it would

hold together. That this design of the lunar module could withstand the stress that would be put upon it in a launch vehicle, so they were verifying that the design was up to the task. Apollo six launched on April four nine. Now the next mission would again include astronauts in the actual command module is the first crude mission after Apollo one. It was called Apolo seven, and the crew consisted of Walter Skira Jr. H Are, Walter Cunningham,

and Don F. Eisel. The launch took place on October eleventh, nineteen. The payload was a Command Service module. There was no lunar module in this particular test. This mission, the crew tested the systems aboard the CSM, including going through the maneuvers that would be necessary for docking with the lunar

module on future missions. So there was no lunar module to dock with, but they went through the actual steps to make certain that the craft could actually maneuver the way they intended, and everything worked the way it was meant to. The fuel cell power system worked well. There were occasional issues with overheating, but the crew was able to solve that by distributing the electric load across the

cells so that no one cell was overworked. The only other minor issue was these spacecraft's coolant lines sweated a bit, so water would collect inside the command module, but the crew used a vacuum to suck up that water and they ejected it out into space along with their p More on that in a second. The a C also stopped working briefly, but the crew was able to manually reset the a C bus breakers to restore service, so that wasn't a big deal. But one thing that proved

to be a little unpleasant. It's time to talk about poop. It was all about the waste disposal system, which is a very elevated way to describe what they had to do. So we're gonna talk about pooping, guys, the astronauts. One of the biggest questions, by the way, the how stuff works would get. One of the most frequently asked questions how stuff works would get was how does going to the bathroom in space work? Well, if you were an Apollo astronaut and you needed to go and make a tuozy,

this is how it worked. So they had to poop into back EAGs. Yep, they had poop bags. The bags had a lining of germicide that was there to help prevent bacteria from multiplying and spreading. Uh. They were bags that were supposed to be easily sealed, and from what I understand, they were easily sealed. And then the crew was to store the used bags in empty food containers. So if you're going rummaging for a snack, you could have a nasty surprise if you didn't keep track of them.

But uh, it was apparently something of a flexibility challenge to use them properly because you had to maneuver out of your pressure suit in order to do this, and also it got a little stinky, and according to NASA, it took between forty five minutes to an hour to use one of the darned things because of getting out of that pressure suit and getting the coveralls adjusted in such a way where you could hold the bag in

the appropriate position and do your business. And that meant that because it took so long, up to an hour just to do this, it meant that you essentially had to hold it until there was a good long stretch of time where you didn't have any mission requirements, you didn't have anything you had to do that was related to the actual mission, and the mission was a long one.

This particular test, it lasted eleven days or nearly eleven days, so on eleven day long mission with three astronauts and close quarters, and this is the process you have to go through. You might be asking yourself, if you're morbidly curious, how much did they have to poop? NASA recorded it. NASA recorded twelve defecations. So imagine working at a job where not only are your restroom breaks logged, but your boss has taken an unusual interest in the product of

said restroom break. Space travel sure is glamorous. The p by the way, was ejected along with that puddled water that I mentioned earlier. They didn't have to remove any clothing to do this. They could just pee in their suits. They had a urine collection service, something that NASA did not go into further detail about, but I think we

can all come up with various hypotheses of what that meant. Anyway, it was in such a way that the urine was actually collected so it could be vented out into space. They weren't just, you know, wearing diapers. All three astronauts caught a cold during the course of the mission, which was incredibly unpleasant. Mucus accumulated and filled up their nasal passages. Man, I'm making space travel sounds sexy, right, So it made it real hard to breathe up. Their Tor's just shaking

her head and looking at me. She's like, I can't believe And only do I have to listen to you talk about pooping and mucus. I'm gonna have to listen to it again when I edit this show. Sorry, Terry, I'll buy you a coke. Anyway, the astronauts found that the only thing that could really clear their noses was if they gave their honkers a real good hard blow, but that would cause pressure to build up in their ears, and it hurt their ear drums to blow their noses,

so it was a very unpleasant experience. NASA, by the way, would refer to the crew morale on this mission as and I quote grumpy. I'm not surprised if you told me to poop in a bag for eleven days and then you gave me a cold, I'd be grumpy too, And I'm not even in space. That's just not cool. Tari is even talking to me, but I can't hear her because she's on the other side of the glass. But she's got things to say about this too. I imagine a Polo seven ended up having a safe splash

down on October twenty nine. Now, I know I said eleven days, but technically, if you were to look at the full time between liftoff and splash down, it was ten days, twenty hours, nine into three seconds. So I'm rounding up to get to those eleven days. But more importantly, it's set the stage for Apollo eight I'll tell you what Apollo eight was all about in just a second, but first let's take another quick break to thank our sponsors. Apollo eight would take a crew further than any human

had gone before. The mission would include a trip around the backside of the Moon and back that involved a maneuver called the trans lunar injection, in which the spacecraft would move out of Earth orbit and travel into an orbit around the Moon before going for a trans Earth injection and essentially reversing this process. It's actually more complicated than reversing the process but coming back to Earth. Astronauts Frank Borman, James Lovell Jr. And William Anders were selected

as the crew of the Apollo eight. The trip to the Moon required two mid course corrections, the first at nearly eleven hours into the mission and the second at sixty one hours eight minutes in the mission, so more than two days. Almost three days into the mission, the Apollo eight spacecraft spent twenty hours in lunar orbit, and it went around the Moon ten times before using the spacecraft's propulsion systems for a trans Earth injection and a

return trip to Earth. Whenever the spacecraft passed on the far side of the moon, radio communication would end. Because the Moon's big, it blocked all the radio signals, so we would lose communication with the astronauts whenever they went around the far side of the moon. By the way, I know all of you know this, but I feel like I should remind folks that the far side of the Moon is what we call the face of the

Moon that is away from the Earth. The Moon is tidally locked with the Earth, so the same side of the Moon always faces us. We never see the other side from Earth. There is, not, however, a dark side of the Moon, or rather, there's not a permanent dark side of the Moon. There is a side of the Moon that's dark, but it's not the same side all the time. All sides of the Moon receive light at one time or another, but there is a permanent far

side of the Moon. Sometimes it's dark, sometimes it's lit up, but it always faces away from us. The astronauts aboard the Apollo eight were the first to see that side of the Moon firsthand. It's pocked with craters from various impacts that it blocked from colliding with the Earth potentially, which is kind of cool, but otherwise it's you know it's the Moon. I'm sure it's really cool to see of close. I'll never get a chance to see it

like that, but you know, it's the Moon. The launch vehicle took off on December one, nine, and the command module splashed down on December, so they spent Christmas up in space. There was no lunar module attached on Apollo eight, it was just the command and service modules that went up. Apollo nine would include a lunar module, but it did not touch down on the Moon instead. The purpose of this mission was to test the rendezvous and docking procedures

between the command Service module and the lunar module. These would all be necessary maneuvers during a mission to the Moon itself. The mission included a simulation of a lunar module rescue mission and the event of a lunar module losing its ability to maneuver in space, so the Command and Service module would have to do all the work in order to orient itself properly and dock with a

lunar module. This was just in case there might be an incident where a lunar module is able to ascend from the Moon but then loses its ability to maneuver, and it would have mean that the pilot of the Command Service module would have to go on a rescue mission during this and the command module and lunar module docked without incident, and the crew was able to transfer from the command module over into the lunar module. And remember there that kind of head to head. That's something

I didn't realize until I was probably a teenager. At that time. I just assumed that the lunar module was somehow on the bottom side of the Command Service module. But that doesn't make any sense. The Command Service module's engine is on the base of the service module, so you can't you can't have a lunar module under that or you would be blasting the lunar module with your engine.

So again, when the whole spacecraft would go into Earth orbit, they would have to have this maneuver where the Command Service module would effectively turn around in space and dock point to point with the lunar module. So it's it's like the two tops of the spacecraft are attaching a course in space top and bottom. That really loses meaning when you're in a microgravity environment, you don't really have

to worry about the top versus a bottom. Uh. It becomes kind of a confusing nomenclature because there's no gravity to use as a point of reference. But it did mean that when the Command Service Module would travel to the Moon, it would have the Lunar module on the front point of it, so that the tip of that cone would attach to the lunar module. Then the the service module of the CSM was where the propulsion system was, and that's where you would get your thrust from your engine.

So the crew went through these maneuvers. They connected the Command Service Module to the lunar module in space, and they moved between the two and on day five, two of the Apollo nine crew transferred to the lunar module and the two modules separated from each other. So you had a Command Service Module with one astronaut in it and a lunar module with two astronauts in it. So you had two craft, two modules that were orbiting the Earth,

both of which were carrying astronauts. The lunar module fired its engine to put it into a different orbit. Originally it was a twelve miles higher than the Command Service Module. Several hours later, the two modules would rendezvous again. The lunar module would go into a lower orbit in preparation for a rendezvous. The two craft were able to dock again and the uh the two astronauts transferred back over

into the command service module. In preparation for landing, they jettison the lunar module because you can't land with a lunar module attached to it, And then later they were separated from the service module and returned to Earth. Re entered the Earth's atmosphere. The Apollo nine spacecraft made one hundred fifty one orbits of the Earth in ten days,

and it touched down on March thirteenth, nineteen sixty nine. Now, Apollo ten was a serious dry run at a lunar landing and included all procedures that would be involved with such a mission with one small exception, and that small exception was there was no actual landing on the Moon. But the mission did put a crude spacecraft, crude as in people were aborted, not that it was crude in design.

It put a manned spacecraft. I hate using that phrase because of the gender, but it put a crude spacecraft in a lunar orbit, and that in would actually go through the whole process of rendezvous and docking with the lunar module in the lunar orbit as if the lunar module had actually gone down to the Moon and ascended back into lunar orbit. It just didn't do that one part of it. It did everything else. This was NASA's last task before trying to actually put people on the Moon.

The Apollo ten craft made only one and a half orbits of the Earth before it moved into a translunar

injection path. The lunar module inside the S four B stage of the launch vehicles separated from the Command Service Module twenty five minutes after the translunar injection and preparation for the docking process that put the lunar module on the nose of the Command Service Module for the rest of the trip to the Moon, and on May twenty two, in orbit around the Moon, the Command Service Module and lunar modules separated and performed a station keeping lunar orbit,

which meant that they were traveling not together because they were separate, but in an orbit where they could have a rendezvous if necessary. One astronaut, John Young, stayed aboard the command module as pilot. The other two astronauts, Thomas Stafford and Eugene Sarnen boarded the lunar module, and that would simulate what the crew of Apollo eleven would do

in preparation for a lunar landing. The command module would stay in orbit around the Moon, and the other two astronauts would get to go down on the lunar surface, not not with Apollo tin, but with Apollo eleven. So in Apollo ten they just simulated this by going into orbit around the Moon, but not actually landing on it.

And after sixteen lunar orbits, the two modules ocked again and Stafford and Sernan came back aboard the Man's Service module with Young, and then they jettisoned the lunar module and returned home. The command module, by that on that particular mission had the nickname Charlie Brown, and the lunar module's nickname was Snoopy, which I thought was cute. The Apollo Tis spacecraft completed all its mission objectives and performed a maneuver to enter trans Earth injection, came back home

without major incident. It splashed down on May nine, and so the stage was set for a real lunar landing. And now we're finally up to Apollo eleven. All the Apollo missions were historic, but this is the one that most people talk about. If they're not talking about Apollo with their team, which we'll get to in the next episode, they talked about Apollo eleven. This was the first mission that put astronauts on the Moon, which is an achievement

only the United States has managed. So far. NASA has done pretty much everything it could do at that point to prepare for this mission. They simulated all the maneuvers in space. They used the various modules that would be needed in order to achieve success. But one thing that had not yet happened was an actual landing of a lunar module on the surface of the Moon and more importantly, launching that module off the surface of the Moon back

into lunar orbit. Apolo eleven would have to do that in order to get the lunar astronauts back home safely. So it was it was scary. It was also thrilling. I mean, the astronauts, as far as I can tell, weren't scared. They were just raring to go. So Poulo eleven, launched on July six, nineteen sixty nine, had Neil Armstrong, Michael Collins, and buzz Aldron aboard. Four days after launch, Armstrong would set foot upon the Moon, a small step

for a man, but a giant leap for mankind. Buzz Aldrin piloted the lunar module, so he went down with Neil Armstrong to the Moon. He was in charge with when the lunar module can leaded its thirteenth orbit of the Moon and then fired its descent engine to start descent towards the Moon's surface. The descent required a last minute change of plans, actually, because the trajectory they were on would have the lunar module land in a crater, and they didn't want to do that, so they had

to change uh sort of at the last minute. They ended up touching down about four miles away from where their predicted landing site had been. The lunar module landed on the dusty surface of the Moon, and about four hours after landing, Neil Armstrong stepped out onto the surface and buzz Aldron would join them about twenty minutes later. Armstrong spent probably around two and a half hours on

the Moon's surface walking around a space suit. Of course, Aldrin would re enter the lunar module about forty minutes ahead of Armstrong. Armstrong really took his time out there. UM can't blame them. I think it probably was fascinating, and not only that, but it was part of the mission. The lunar module spent about twenty one and a half hours on the surface of the Moon. Meanwhile, the command module continued to orbit the Moon up above. Must have

been pretty lonely up there, honestly. The lunar module engaged its ascent stage engine at one four hours twenty two minutes into the mission. Less than ten minutes later, the lunar module was in a lunar orbit, so it took less than ten minutes to go from the surface of the Moon into lunar orbit, and the command module was in its twenty five orbit around the Moon at that point. The two modules docked at one hours three minutes into the mission, and Armstrong and Aldrin then transferred back over

to the Command Service module. A few hours later, the crew jettison the lunar module into lunar orbit, and then they prepared to go home. The Apollo eleven completed fifty nine hours of lunar orbit before moving into a trans Earth injection. This was on July one. The Apollo eleven spacecraft would touchdown on Earth on July nine. Astronauts had

successfully traveled to the Moon and returned home safely. I am still amazed even now looking back on that achievement and thinking all the things that were required in order to make that a success. It is a phenomenal testament to the ingenuity of humans. Countless men and women worked together to make this happen. And when I look up at the Moon and think people have been there, it blows my mind to this day. But it's time for

me to wrap up this episode. In our next episode, I'm going to give a quick overview, you know me, It probably won't be quick. I'll give an overview of what the other Apollo missions were all about. All of them are important and they all really deserve their own episodes,

but I'll give an overview of those. Then I'll transition to talking about the Soyuz spacecraft, the Soviet spacecraft that was used to not only doc with the first space station, but also ended up being a vehicle that transported the first space tourists in space. Though from what I understand, they all hate being called that. We'll talk that about that in the next episode. Now as I wrap up here, I want to tell you guys about our new merchandise store,

are t public site. It's live and it's awesome. We finally have tech Stuff merchandise. You can buy t shirts, tote bags, phone cases, stickers, all sorts of stuff, coffee mugs. I've got a tech Stuff coffee mug now. It's awesome. If you love the tech Stuff logo, you can get that on a shirt now. But my favorite design of all the ones we've done so far, and we've only just started, has a sketch of Ada Lovelace, the Enchantress of Numbers, and it says code like a girl. And

I love that shirt. I've already put in my orders for merchandise with that stuff on it. But here's the cool thing too, It's not only do you get this awesome stuff that you guys have been asking for for a while. When you purchase something, some of that money actually goes to the show. You'll be helping our show with those purchases. So go check it out see if there's anything you like. Anything you buy, you are actually helping us make this show. You are part of the team,

and I greatly appreciate it. We have new designs going up all the time. In fact, I submitted a brand new design just before I came into the studio, and I hope to see that included in the store very soon. If you want to check it out, it is t public dot com slash tech Stuff. That's t E E Public dot com slash tech Stuff. Check those out see what you think. If you have any suggestions for future episodes, send me an email addresses tech stuff at how stuff works dot com, or drop me a line on Facebook

or Twitter. The handle at both of those is text stuff H s W. Don't forget check out our Instagram account. Go follow that. You might end up seeing some designs before they even go live in the tech stuff store, and I'll talk to you again really soon for more on this and thousands of other topics. Because it how stuff works dot com.