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'm your host, Jonathan Strickland. I'm an executive producer at
Speaker 1: how Stuff Works and I love all things tech. And
Speaker 1: we are continuing our epic series about space and space travel.
Speaker 1: And I've covered the various spacecraft involved during the actual
Speaker 1: space race, from the vast Stock to the saw Us,
Speaker 1: from the Mercury to the Apollo, but I didn't really
Speaker 1: go into much detail about the launch vehicles or what
Speaker 1: we would more casually refer to as the rockets. So
Speaker 1: today we're gonna talk about rockets and the science behind
Speaker 1: them and some of the ones that have been used
Speaker 1: to put stuff what was once on Earth out in
Speaker 1: space somewhere. And don't worry, I'm not going to cover
Speaker 1: every single rocket that ever was put to such use.
Speaker 1: That would sound like I was reading off a very
Speaker 1: weird phone book, because it would involve not just all
Speaker 1: these odd names that we as Americans we asn't I'm
Speaker 1: saying myself here the Americans created, but also all the
Speaker 1: different designations that have been made by various countries around
Speaker 1: the world. Lots of countries have made launch vehicles. So
Speaker 1: I'm just gonna focus on some of the ones from
Speaker 1: the space race period because I think, uh, you know,
Speaker 1: it relates to the episodes I just did mainly, and
Speaker 1: also it has a nice narrow focus. The history of
Speaker 1: rockets stretches far back before there was ever a space race,
Speaker 1: or before there was a Soviet Union, or before there
Speaker 1: was a United States of America. And of course by
Speaker 1: that I mean before there were those nations. Obviously the
Speaker 1: land masses were there and there were people living on them.
Speaker 1: But you know what I mean. The origins of the
Speaker 1: rocket are closely tied to that of fireworks, and I've
Speaker 1: covered fireworks in previous episodes. Scholars have nailed down the
Speaker 1: emergence of rockets in Chinese alchemy sometime during the dynasty
Speaker 1: that stretched from nine sixty Common era to twelve seventy
Speaker 1: nine Common Era. The former curator of rockets for the
Speaker 1: Smithsonian National Air and Space Museum, a guy named Frank Winter,
Speaker 1: attempted to narrow that down a bit, and his work
Speaker 1: suggested that during the eleventh century, Chinese alchemists were trying
Speaker 1: to suss out a formula that would lead to eternal life.
Speaker 1: They were attempting to make practical use of the Chinese
Speaker 1: philosophy that all the universe is divided into passive and
Speaker 1: active forces, and that mixing your yin and yang materials
Speaker 1: in a proper way would create various amazing results, such
Speaker 1: as presumably never dying. So they never landed on a
Speaker 1: mixture that would preserve life indefinitely, but some of the
Speaker 1: mixtures did up having other interesting properties, like blowing up
Speaker 1: if you lit them, so they effectively invented an early
Speaker 1: form of gun powder. By twelve thirty two, the Chinese
Speaker 1: were using rockets in warfare. They had a weapon that
Speaker 1: they called the fai Ju san Uh. And I know
Speaker 1: I'm mispronouncing that. I apologize my Chinese is terrible, but
Speaker 1: it means flying fire lances. And if you listen to
Speaker 1: the fireworks episodes that we did on text of years ago,
Speaker 1: you know there are various myths and legends about Chinese
Speaker 1: thinkers who tried to use rockets for flight and the
Speaker 1: various results of those experiments. So I'm not going to
Speaker 1: go into those here. Instead, we're just gonna skip ahead
Speaker 1: a few centuries. In the fifteen nineties, in Germany, there
Speaker 1: was a fireworks maker named Johann schmid Lap, who attempted
Speaker 1: to create fireworks that could reach much higher altitudes through
Speaker 1: a process called staging. Staging is where you divide up
Speaker 1: a rocket into two or more stages, and each stage
Speaker 1: contains its own propellant. So when the first stage burns out,
Speaker 1: it ignites the second stage, which in schmid Lab's case
Speaker 1: was a smaller rocket that was carried by a larger
Speaker 1: first stage rocket. So the first stage rocket ignites launches
Speaker 1: as it gets towards the end of its fuel, it
Speaker 1: ignites the fuel inside the second rocket, which then continues
Speaker 1: to launch and go even higher into the sky and
Speaker 1: deliver the payload way up in there, and you get
Speaker 1: a really impressive firework. While schmid Lap made a practical,
Speaker 1: practical multi stage rocket, the idea had previously been theorized
Speaker 1: by an Austrian military engineer named Conrad hass hass wrote
Speaker 1: a manuscript about his ideas that predated schmid Laps designs
Speaker 1: by a few decades, including multi stage rockets. Even talked
Speaker 1: about the possibility of using liquid fuels as propellant, although
Speaker 1: that would take quite some time to come true. Now,
Speaker 1: whether schmid Lap knew of Hassa's work or not. I
Speaker 1: don't know. Maybe he did. It's possible that this was
Speaker 1: a case of two people coming up with essentially the
Speaker 1: same idea around the same time that has happened before.
Speaker 1: Or it could be that schmid Lap had heard of
Speaker 1: Hassa his ideas and that schmid Lap was the one
Speaker 1: who was able to make practical use of them. Either way,
Speaker 1: whether he came up with the idea or not, schmid
Speaker 1: Lap was the one who actually made it work. In
Speaker 1: seven Sir Isaac Newton published his work Principia, which included
Speaker 1: his three Laws of motion. So we see that the
Speaker 1: practical understanding of rocketry preceded a more nuanced scientific understanding
Speaker 1: of what was going on by several centuries, which is
Speaker 1: often the case where we notice something, we observe something interesting,
Speaker 1: and we even make use of that something for some time,
Speaker 1: but we don't have a full understanding of what's really
Speaker 1: going on until much later. That has happened on numerous
Speaker 1: occasions throughout human history. So what are the three laws
Speaker 1: of motion and why are they important? Well, the first
Speaker 1: law is every object in a state of uniform motion
Speaker 1: tends to remain in that state of motion unless an
Speaker 1: external force is applied to it. We also call this
Speaker 1: the law of inertia. So, for example, if there is
Speaker 1: a rock sitting on a level section of ground, we
Speaker 1: would expect that rock to just sit there, to remain
Speaker 1: in that position, to stay still, unless some external force
Speaker 1: like someone's foot were to come in and be applied
Speaker 1: to the rock. So soone kicks the rock, then we
Speaker 1: would expect it to move. But we wouldn't expect the
Speaker 1: rock to move on its own. It wouldn't just spontaneously
Speaker 1: start rolling around. That would be in violation of the
Speaker 1: first law of motion. The second law of motion is
Speaker 1: that the relationship between an objects mass, it's acceleration and
Speaker 1: the applied force is force equals mass times acceleration. Acceleration
Speaker 1: and force are vectors, meaning they don't just have a magnitude.
Speaker 1: They also have a direction, so you have to describe
Speaker 1: them as having a direction while you're working with them.
Speaker 1: You can't just give, you know, just a unit and
Speaker 1: be accurate and this law. In this law, the direction
Speaker 1: of the force vector is the same as the direction
Speaker 1: of the acceleration victor, so you can't have an acceleration
Speaker 1: vector that's an opposite direction of the force vector. The
Speaker 1: equation lets us understand how velocities change when we apply
Speaker 1: different forces to the system. And a change in velocity
Speaker 1: is acceleration, right, Velocity itself is uh is speed and direction,
Speaker 1: So acceleration is when you change something about that. You
Speaker 1: either change the speed, so you make it speed up,
Speaker 1: or you make it slow down, or you change the direction,
Speaker 1: which you know because velocity is a vector, and either
Speaker 1: one of those would be considered a change in acceleration,
Speaker 1: or rather it would be acceleration itself. And the third
Speaker 1: law of motion is for every action, there is an
Speaker 1: equal and opposite reaction. So you've probably heard this before,
Speaker 1: and I'm sure you have a decent understanding of it,
Speaker 1: but just in case, here's a way of thinking about.
Speaker 1: Imagine that you're standing on a platform that's suspended by ropes,
Speaker 1: right like it's a square platform. There are four ropes,
Speaker 1: one at each corner, and there's a second platform on
Speaker 1: a column that's in front of you. But in order
Speaker 1: to get there, you're gonna have to take a pretty
Speaker 1: big step. Not not a huge step, but a decent one.
Speaker 1: As you take that step, if there were another observer
Speaker 1: watching all this, they would notice that the platform you
Speaker 1: stand on would move the opposite direction of where you
Speaker 1: were stepping. This is that equal but opposite reaction. That's
Speaker 1: an exemplification of Newton's third law of motion. It's also
Speaker 1: ultimately what explains the phenomenon of a rocket flying into
Speaker 1: the air. When it's blasting what appears to just be
Speaker 1: fire and smoke out of its business end, the rocket
Speaker 1: is actually throwing mass in one direction in the form
Speaker 1: of very high pressured gas. The rocket itself moves in
Speaker 1: the opposite direction because of this. If you were to
Speaker 1: sit in an office chair that has wheels on it,
Speaker 1: and then you had a mess and ball in your hands,
Speaker 1: and you threw the mess and ball straight ahead of you,
Speaker 1: that you and the chair would roll backward. Because of
Speaker 1: this principle, rockets work the same way. It's just that
Speaker 1: the rocket is throwing up mass in the form of
Speaker 1: that high pressure gas an incredible rate. So remember that
Speaker 1: second law forces equal to mass times acceleration. That's also
Speaker 1: very important. The rocket has a lot of mass, particularly
Speaker 1: when it's full of fuel. You have the mass of
Speaker 1: the rocket structure and you have the mass of all
Speaker 1: the fuel inside of it. When a rockets engine, which
Speaker 1: is a reaction engine, It's important to note because when
Speaker 1: we hear the word engine. I don't know about you,
Speaker 1: but when I hear the word engine, I'm usually thinking
Speaker 1: about a mechanical device that forms some form of rotational power, right,
Speaker 1: a rotational force, like a reciprocating gasolene engine. That's kind
Speaker 1: of what I think about. But a rocket engine is
Speaker 1: a reaction engine. Rocket engines fling mass in that form
Speaker 1: of hot gas uh at a very high rate of acceleration,
Speaker 1: and the combination creates a lot of force. Right. So,
Speaker 1: however much mass it is times that acceleration that equals
Speaker 1: the force. Well, the equal and obvious that reaction means,
Speaker 1: if you're pushing that much mass downward at a very
Speaker 1: fast rate, then you're moving upward. Uh. And the speed
Speaker 1: at which you move is based upon how fast and
Speaker 1: how much stuff you're pushing down That that equation tells
Speaker 1: us all of this stuff, and we can actually figure
Speaker 1: out how much acceleration the rocket will experience if we
Speaker 1: know the mass and the acceleration of the hot gases
Speaker 1: coming out of its engine. The two sides of the
Speaker 1: equation have to balance out. It has to be equal
Speaker 1: and opposite, right, So rocket science is hard But let's
Speaker 1: go back to that office chair and medicine ball example,
Speaker 1: because that makes it way easier to understand. So practical example,
Speaker 1: let's say I'm sitting in an office chair and I
Speaker 1: have a mass of about sixty eight ms. The chair
Speaker 1: has a mass of about twenty two kilograms, so collectively
Speaker 1: the chair and I are nine DRAMs. The medicine ball
Speaker 1: I have has a mass of four point five rams.
Speaker 1: So at the very beginning of this I have a
Speaker 1: total mass of ninety four point five ms because I'm
Speaker 1: holding the medicine ball right, and then I also have
Speaker 1: a velocity of zero. I'm not moving, so I'm staying still.
Speaker 1: I've got this messin ball in my hands, and then
Speaker 1: I throw the mess and ball straight out in front
Speaker 1: of me at fifteen per second. That's about thirty three
Speaker 1: and a half miles per hour, and that's probably way
Speaker 1: faster than I could actually throw a messin ball. But
Speaker 1: forget that for now. How fast am I going to
Speaker 1: travel back in my chair? How fast will the chair
Speaker 1: roll backward in opposite direction from my throw? Well, to
Speaker 1: understand that, we take the velocity of the messin ball
Speaker 1: times it's mass, So we take that fifteen per second
Speaker 1: times four point five ms, which gives us sixty seven
Speaker 1: point five Newton's technically that represents the force of the
Speaker 1: medicine ball flying away from me. There must be an
Speaker 1: equal and opposite reaction, So that means the product of
Speaker 1: my mass and vela city has to equal negative sixty
Speaker 1: seven point five. It's equal and opposite of the original.
Speaker 1: Now it's negative because we're looking at velocity in the
Speaker 1: opposite direction of the medicine ball's flight, so it's it's
Speaker 1: from the perspective of medicine ball's flight being positive. Mine
Speaker 1: has to be negative. So it doesn't mean that I
Speaker 1: have some sort of weird negative unit of measurement. Instead
Speaker 1: is referring to it being a different direction and opposite direction.
Speaker 1: So again forces mass times acceleration, and we know what
Speaker 1: my mass is with the chair right, it's nine. And
Speaker 1: we know that the force is equal and opposite of
Speaker 1: the force that was in the medicine ball side of
Speaker 1: the equation, so we know it's the forces minus sixty
Speaker 1: seven point five. So that means we have to divide
Speaker 1: both sides by my mass. We divide minus sixty seven
Speaker 1: point five by my mass of ninety kilograms and we
Speaker 1: end up getting minus point seven five meters per second,
Speaker 1: So that means I'm traveling backward in my chair at
Speaker 1: point seven five per second initially before friction slows me down.
Speaker 1: Rocket science is exactly like that, only of course, way
Speaker 1: more difficult. We'll get into why it gets way more
Speaker 1: difficult in just a second, but first, y'all, I need
Speaker 1: to take a quick break. I'm gonna thank my sponsor.
Speaker 1: The science of rocketry continued in large part because rockets
Speaker 1: could be effective weapons of war. In four engineers discovered
Speaker 1: that by designing jet vents on an angle so they're
Speaker 1: not coming just straight out, a rocket would spin when
Speaker 1: it was ignited, and that spinning motion would actually create
Speaker 1: a stabilization in the rockets flight path, kind of like
Speaker 1: a bullet experience when it emerges from a gun, It
Speaker 1: spins and that produces stability. Uh. The st to ability
Speaker 1: of spinning objects would become a very important component, not
Speaker 1: just in space travel, but in technology in general. It's
Speaker 1: you know, I've talked about that with gyroscopes in Constantine.
Speaker 1: Soolkov Sky, who I talked about in the first episode
Speaker 1: of this whole series, proposed the possibility of space travel
Speaker 1: through rocketry. Moreover, he theorized that a liquid propellant would
Speaker 1: be a more suitable fuel source to provide the energy
Speaker 1: necessary to push a rocket into space, but had not
Speaker 1: quite worked out how that would actually happen. Solkovski worked
Speaker 1: on some really important details about the relationship between a
Speaker 1: rocket's mass and its speed and what it would take
Speaker 1: to get a rocket into space. So let's take a
Speaker 1: few moments to understand the calculations that are necessary. Now
Speaker 1: we've already covered the equal and opposite reaction. We understand
Speaker 1: that that whatever we want the rocket to do is
Speaker 1: going to be based upon the amount of mass it's
Speaker 1: throwing out through its engine and how fast it's throwing
Speaker 1: that mass out. But now we have to consider some
Speaker 1: other complicating fact. There's first, a rockets mass when it's
Speaker 1: fully fueled is different than the rockets mass one second
Speaker 1: before all the fuel burns up. That mass is decreasing.
Speaker 1: Now the mass is not being destroyed, it's just being
Speaker 1: thrown out of the engine. Because you cannot create or
Speaker 1: destroy matter. You can't convert it from one form to another,
Speaker 1: but you can't destroy it, So that mass isn't being destroyed.
Speaker 1: If you talk about a rocket that has, you know,
Speaker 1: twenty thousand tons of fuel aboard it. That twenty thousand
Speaker 1: tons of fuel gets turned into twenty thousand tons of
Speaker 1: high pressured gas during the process of being shot out
Speaker 1: of the engine. So burning fuel means you're ejecting mass
Speaker 1: through the rocket engine. So the rockets mass decreases throughout
Speaker 1: the engine burn and that affects the equations. And if
Speaker 1: you want that rocket to actually carry something into space,
Speaker 1: the payloads mass has to be taken into account along
Speaker 1: with the rocket in the fuel. Sometimes that can seem
Speaker 1: like it's negligible, but it's still really important. So getting
Speaker 1: a payload into space as a matter of the earning,
Speaker 1: how much force you will need to escape Earth's gravity,
Speaker 1: how large your rocket will need to be to do that,
Speaker 1: how much fuel you're gonna need to move that rocket,
Speaker 1: which in turn might mean that you have to make
Speaker 1: changes to how big the rocket is. And as this continues,
Speaker 1: you can easily see it get away from you. Right,
Speaker 1: you could say, well, to move something of this mass,
Speaker 1: i'm gonna need x amount of fuel. But if you
Speaker 1: have X amount of fuel, that's too much fuel for
Speaker 1: this rocket. So the rockets gonna have to be bigger,
Speaker 1: but the rockets bigger than the mass is greater, which
Speaker 1: means I'm actually gonna need more fuel than what I
Speaker 1: thought before, and that can quickly run away from you.
Speaker 1: So that's another complication. Any changed the design of the
Speaker 1: rocket or the payload is going to affect the amount
Speaker 1: of fuel you're gonna need to use. And of course,
Speaker 1: when you add more fuel, you add more mass, so
Speaker 1: it's really slippery slope. When you burn the fuel, you
Speaker 1: create this high pressure gas, and releasing that gas in
Speaker 1: a specific direction provides the thrust to push a rocket.
Speaker 1: The weight of fuel you burn is equal to the
Speaker 1: weight of the gas that is generated, So if you
Speaker 1: burn a ton of fuel, you have created a ton
Speaker 1: of high pressure gas. The burning process is what actually
Speaker 1: accelerates the mass with the release through the nozzle that
Speaker 1: provides thrust, and the nozzle also can increase the the
Speaker 1: acceleration or it accelerates. Rather, I shouldn't say increases the acceleration,
Speaker 1: it accelerates the mass further. And by this incredible acceleration
Speaker 1: multiplied by the mass of the high pressure gas that
Speaker 1: you're shooting out of this rocket engine, that's what creates
Speaker 1: the force that allows a rocket to lift off the ground,
Speaker 1: and we measured thrust in either Newton's as I mentioned earlier,
Speaker 1: or in the good old us of A. Because we
Speaker 1: obviously refuse to do things the way the rest of
Speaker 1: the world does it, we refer to it as pounds
Speaker 1: of thrust. One pound of thrust is equal to four
Speaker 1: point four or five Newton's of thrust, and one pound
Speaker 1: of thrust is what would take to keep a one
Speaker 1: pound object stationary against the force of gravity on Earth.
Speaker 1: One Newton is the amount of force necessary to make
Speaker 1: one mass of one kilogram accelerate at a rate of
Speaker 1: one m per second squared. This means on Earth, a
Speaker 1: mass of one kilogram pushes against whatever it is resting
Speaker 1: on with a force of nine point eight Newton's on average.
Speaker 1: So if you have a kilogram weight on a table,
Speaker 1: that kilogram is effectively pushing against the table with nine
Speaker 1: point eight newtons of force, the tables pushing back with
Speaker 1: nine point eight newtons, a force equal and opposite. And
Speaker 1: the reason why it's nine point eight Newton's it's because
Speaker 1: Earth's gravity, at least at mean sea level, is nine
Speaker 1: point eight meters per second squared. To get space to
Speaker 1: get up to space. You have to travel fast enough
Speaker 1: to break free of the gravitational force of the Earth.
Speaker 1: We actually figured out exactly what speed we need to
Speaker 1: do that, so that speed would be eleven kilometers per
Speaker 1: second or seven miles per second. You gotta get at
Speaker 1: at that speed in order to breakthrough an escape Earth's gravity.
Speaker 1: On March sixteenth, ninety, Robert Goddard, whom I also mentioned
Speaker 1: in that earlier episode, created a rocket that used liquid
Speaker 1: oxygen and gasoline as propellant. Liquid oxygen was used as
Speaker 1: the oxidizer. He also got to work developing multi stage
Speaker 1: rockets and liquid fuel rockets. This was a big deal.
Speaker 1: It was the first liquid fuel rockets. They're very important,
Speaker 1: but up until Goddard, no one had figured out how
Speaker 1: to do them. They had been using solid fuel rockets,
Speaker 1: like the gunpowder rockets that the Chinese had created way
Speaker 1: back in the Sum dynasty. Uh. Solid fuel rockets burned quickly,
Speaker 1: and if they're designed properly, they do not explode. It's
Speaker 1: easier said than done. It requires finding the right mixture
Speaker 1: of components so as you can have a rapid but
Speaker 1: controlled burn, and uncontrolled burn turns into an explosion. So
Speaker 1: typically solid fuel rockets have a whole kind of down
Speaker 1: the center think of think of a solid fuel rocket.
Speaker 1: Think of it as taking the case of the rocket
Speaker 1: off and you have a a solid cylinder of fuel.
Speaker 1: Down the center of that cylinder is a tube or
Speaker 1: a hole, and you ignite the fuel in the center
Speaker 1: of this tube and it burns from the center out
Speaker 1: towards the edge where it's making contact with the casing
Speaker 1: of the rocket, and then the fuel is spent. The
Speaker 1: thing about it is, once you ignite a solid fuel rocket,
Speaker 1: it burns until all the fuel's gone. There's no stopping
Speaker 1: the engine once you start. Liquid rockets, however, offer up
Speaker 1: more control. You can actually turn on or turn off
Speaker 1: the burn process, so you can control the rocket engine
Speaker 1: that way. But they also come with other challenges. So
Speaker 1: to burn stuff, you need three things. We all remember
Speaker 1: the triangle, right, You need heat, you need fuel, and
Speaker 1: you need an oxidizer. And here on Earth we tend
Speaker 1: to just rely on oxygen. Right, that's our oxidizer. We
Speaker 1: also don't have to do anything special with it if
Speaker 1: we're on the surface of the planet. But in liquid
Speaker 1: rocket design, you need to have an oxidizer incorporated into
Speaker 1: the design of the propulsion system in order to create
Speaker 1: an environment in which fuel can actually burn. You cannot
Speaker 1: burn fuel without an oxidizer. Liquid oxygen is a frequent oxidizer,
Speaker 1: or at least in the early rockets, that was frequently used,
Speaker 1: and that's what Goddard did. The oxidizer and fuel end
Speaker 1: up being pumped into a combustion chamber and it's mixed there,
Speaker 1: so you get a fine mix of oxidizer and fuel
Speaker 1: which can then be ignited that ends up burning off
Speaker 1: and creating this high pressure gas that then can be
Speaker 1: directed through a nozzle to create the thrust. The combustion
Speaker 1: chamber and the nozzle can get really really hot, like
Speaker 1: hot enough to break down if the heat goes unchecked.
Speaker 1: So typically a liquid fueled rocket design will include either
Speaker 1: the oxidizer or the fuel as a super cold cryogenic
Speaker 1: liquid like liquid oxygen obviously has to be a cryogenic liquid,
Speaker 1: or liquid hydrogen has to be a cryogenic liquid. You
Speaker 1: have to get them at very very cold temperatures in
Speaker 1: order to keep that stuff in liquid form. Typically those
Speaker 1: cryogenic liquids would pass through lines that are adjacent to
Speaker 1: the combustion chamber and nozzle and transfer heat away from
Speaker 1: those parts of the rocket engine and the pumps that
Speaker 1: provide the oxidizer in the fuel to the combustion chamber
Speaker 1: have to be incredibly strong because inside that combustion chamber
Speaker 1: you're generating that high pressured gas. If the pumps are
Speaker 1: not strong enough to overcome that high pressure, then the
Speaker 1: gas is gonna go up those pump lines instead of
Speaker 1: out the nozzle, or they'll go up the pump lines
Speaker 1: and out the nozzle, and you don't want that. So
Speaker 1: you have to have very very strong pumps in a
Speaker 1: liquid fuel rocket, which is why, uh, it's a complicated process.
Speaker 1: Is a complicated technology, and it's why it took a
Speaker 1: good long time for someone to develop one that could
Speaker 1: I actually work. Even Goddard's demonstration was pretty modest, and
Speaker 1: if you saw the launch today and you just watched
Speaker 1: as it happened, you'd think, well, what's the big deal.
Speaker 1: It didn't even go that high and when a few
Speaker 1: meters up in the air and then came right back down.
Speaker 1: But when you understand the technology behind it, how complicated
Speaker 1: it was, it was very impressive. Most importantly, you can
Speaker 1: control the burn of a liquid fueled rocket because you
Speaker 1: can stop the flow of oxidizer and fuel into the
Speaker 1: combustion engine. You can turn the pumps off and once
Speaker 1: there's nothing to burn the engines off, it's not gonna
Speaker 1: create any more thrust, and then you could start it
Speaker 1: back up again when you needed to, so you it
Speaker 1: wasn't an all or nothing the way a solid fuel
Speaker 1: rocket would be. Solid fuel was much more simple, but
Speaker 1: it was more limited. So liquid fuel is the way
Speaker 1: a lot. Pretty much all the propulsion systems of all
Speaker 1: the spacecraft had to be liquid fueled. They there were
Speaker 1: several spacecraft that would also depend on solid fuel for
Speaker 1: some stage or another. May it was like a retro
Speaker 1: rocket or a breaking rocket or something like that, or
Speaker 1: sometimes solid fuel booster rockets to get up into space.
Speaker 1: But when it came to fine tuning, we're talking about
Speaker 1: liquid fueled rockets. Well, I've got a lot more to
Speaker 1: say about rockets, but before I jump into that, let's
Speaker 1: take another quick break to thank our sponsor. In the
Speaker 1: nineteen forties, German engineer Werner von Braun, who would later
Speaker 1: be brought over to the United States under Operation paper Clip,
Speaker 1: worked on developing the V two rocket for Germany, and
Speaker 1: those rockets used a mixture of oxygen and alcohol for propellant.
Speaker 1: They consumed fuel at a rate of one ton of
Speaker 1: fuel every seven seconds, So that tells you how much
Speaker 1: mass is being thrown out by this rocket engine. It's
Speaker 1: a lot a ton of fuel every seven seconds. And
Speaker 1: this was the first rocket design that could actually cross
Speaker 1: the Carmen line into who space. The Americans would end
Speaker 1: up taking not just the German scientists and engineers, but
Speaker 1: also some of the V two rockets during Operation paper Clip,
Speaker 1: and then adapt those rockets for scientific experiments such as
Speaker 1: making measurements of the atmosphere at very high altitudes. The
Speaker 1: nineteen fifties saw the development of i C b ms,
Speaker 1: also known as intercontinental ballistic missiles scary scary technology. This
Speaker 1: is where we get into the nuclear arms race, and
Speaker 1: that whole assured uh mutually assured mass destruction where you're
Speaker 1: your whole philosophy is we need to build up our
Speaker 1: weapons enough so that no one will dare pick on us,
Speaker 1: and our enemies have their weapons built up in the
Speaker 1: same way, so that way will always be at peace,
Speaker 1: because if we were to launch an attack, everybody would die.
Speaker 1: And so the only way to win is not to
Speaker 1: play anyway without I c b ms. We also would
Speaker 1: not have had the launch vehicles that we use during
Speaker 1: the Space race. So some scientific good came out of this,
Speaker 1: uh and a lot of scary military stuff came out
Speaker 1: of it too, But this is where we started getting
Speaker 1: into putting stuff into space with satellites like spot Nick
Speaker 1: or spacecraft like the Mercury Capsule. So now I can
Speaker 1: talk a little bit more about specific rockets. Not generally speaking,
Speaker 1: a space rocket tends to have four major components, each
Speaker 1: of which might have thousands of individual parts to them.
Speaker 1: You've got the actual casing or structure of the rocket.
Speaker 1: That's the physical form of the rocket. It's the bit
Speaker 1: that holds all the other bits in place. And then
Speaker 1: you've got the propulsion system that would be the fuel,
Speaker 1: the rocket engine, all the components necessary for providing thrust.
Speaker 1: There's a guidance system because you want the rocket to
Speaker 1: go where you want it to go, so you have
Speaker 1: to have some way of guiding it, of steering it,
Speaker 1: and there are multiple ways that that has happened throughout
Speaker 1: the years. So you gotta have a guidance system. And
Speaker 1: then you have the payload that's whatever the rocket is carrying,
Speaker 1: like in these cases we're talking about satellites or spacecraft. Obviously,
Speaker 1: in military applications you might be talking about the satellite,
Speaker 1: but you're probably talking about some sort of warhead. And
Speaker 1: most rockets contain at least two stages, with each stage
Speaker 1: having its own guidance system and propulsion system. The final
Speaker 1: stage is usually what ends up carrying the payload. The
Speaker 1: earliest designs for I C b m s which were
Speaker 1: intended as weapons of mass destruction that would carry a
Speaker 1: nuclear weapon. Uh, we're sort of the brainchild again of
Speaker 1: Werner von Brawn. He was working on a design in
Speaker 1: Germany during World War Two. It was designated the A
Speaker 1: nine Slash ten. The US and the Soviet Union both
Speaker 1: rushed to develop I C b ms in the wake
Speaker 1: of World War Two. That was at the beginning of
Speaker 1: the Cold War between the two countries. The Soviets got
Speaker 1: there first. They built the first I C b M.
Speaker 1: It was a two stage missile and it was called
Speaker 1: the R seven. It was one twelve feet or thirty
Speaker 1: four meters long and measured nine point nine ft or
Speaker 1: three point two meters in diameter. It used liquid oxygen
Speaker 1: as the oxidizer. In those early early ones and kerosene
Speaker 1: was the fuel in the early ones. It weighed two
Speaker 1: eight metric tons. The first stage of the rocket consisted
Speaker 1: of four strap on rocket boosters around a central rocket engine.
Speaker 1: Uh The central engine would continue providing thrust through both
Speaker 1: stages of the rocket. The R seven demonstrated that the
Speaker 1: Soviet Union could launch a missile at targets on the
Speaker 1: other side of the world, and the Soviets used modified
Speaker 1: versions of the R seven for splot Nick, for the
Speaker 1: VOS stock spacecraft, for vos CAD, and for the early
Speaker 1: Soya's launches. About half of the launches used using the
Speaker 1: early R seven launch vehicles suffered failures. It was notoriously
Speaker 1: unreliable early early on in its design, and that prompted
Speaker 1: the Soviet engineers to revisit that design and make changes
Speaker 1: to improve reliability. But the R seven would continue to
Speaker 1: the point where today the Soviets are using launch vehicles
Speaker 1: that are based off that same design. Even the Soyuz
Speaker 1: rockets that we use are relying upon those types of
Speaker 1: launch vehicles. They're still part of that our seven family.
Speaker 1: So some of the variants also include the option of
Speaker 1: a third stage of the rocket. That was one of
Speaker 1: the things that was planned when the Soviets were thinking
Speaker 1: about going to the Moon. Over in the United States,
Speaker 1: the Atlas rocket would become the first American I CBM.
Speaker 1: The first successful demonstration of an Atlas rocket took place
Speaker 1: a little more than a year after the Russians had
Speaker 1: launched sput Nik into orbit, and the Atlas, like the
Speaker 1: R seven, had a notorious reputation for malfunctions and launch failures.
Speaker 1: Though General Dynamics and corvet Are, the companies that were
Speaker 1: building the missile, worked very hard to solve those design
Speaker 1: problem loans, but it was a particularly complicated rocket design,
Speaker 1: liquid fueled rocket, and it was really complex, and that
Speaker 1: created multiple points for potential failure, so all that stuff
Speaker 1: had to be worked out. The Atlas LV three B
Speaker 1: or Atlas D became the launch vehicle for the last
Speaker 1: four manned Mercury Project missions. The failure rate created real concern,
Speaker 1: but the Atlas was literally the only vehicle that the
Speaker 1: United States had access to that would be capable of
Speaker 1: putting a payload into orbit. Atlas had what was referred
Speaker 1: to as a stage and a half design, with a
Speaker 1: first stage that was bolstered by booster. A booster rocket
Speaker 1: now the first three manned Mercury missions. What did they use?
Speaker 1: I mean if the last four used the Atlas d
Speaker 1: um what did the actually I guess the first two
Speaker 1: Mercury missions, there were only six manned Mercury missions. What
Speaker 1: did they rely on? Well, they relied on a rocket
Speaker 1: called the red Stone that was the first American space booster.
Speaker 1: But the Redstone did not have enough fuel capacity or
Speaker 1: thrust capability to put a payload into orbit. It could
Speaker 1: only do suborbital flights. So while the Redstone was the
Speaker 1: first space booster for a manned mission, UH, it was
Speaker 1: not capable of putting anyone into orbit. For the Gemini missions,
Speaker 1: NASA would end up using the Titan two g LV
Speaker 1: that was their launch vehicle of choice. The Titan, too
Speaker 1: was a second generation I C B M and it
Speaker 1: was a two stage liquid fuel rocket that used nitrogen
Speaker 1: tetroxide as an oxidizer I mentioned that earlier and aerosigne
Speaker 1: fifty as a fuel. And it was a simpler design
Speaker 1: than the Atlas, which made it a little more reliable.
Speaker 1: There were fewer things that could go wrong. The Apollo
Speaker 1: program would rely on two variants of a launch vehicle
Speaker 1: called the Saturn. The Saturn one or I B if
Speaker 1: you prefer, that's the one B for all Apollo missions
Speaker 1: up to and including Apollo seven. Then starting with Apollo eight,
Speaker 1: they switched to the Saturn five, so a follow eight
Speaker 1: to Apolo seventeen used the Saturn five launch vehicle. The
Speaker 1: Saturn one was the first heavy lift spacecraft launch vehicle
Speaker 1: in the United States, and while NASA was originally going
Speaker 1: to use it for the early Apollo missions, the organization
Speaker 1: ultimately decided that the cuts they would need to make
Speaker 1: in payload weight in order to make this work weren't
Speaker 1: worth the efforts, so instead they decided that they would
Speaker 1: use the upgraded Saturn one B instead. Uh It was
Speaker 1: a two stage rocket, with the second stage called the
Speaker 1: S four B, which I talked to about in previous episodes.
Speaker 1: A modified version of the S four B would become
Speaker 1: the third stage for the Saturn five. The Saturn five
Speaker 1: was capable of sending a fueled CSM Command Service Module
Speaker 1: and LM or lunar module to the Moon. The S
Speaker 1: four B would provide the thrust needed to go from
Speaker 1: an Earth orbit into a translunar injection. So the Centurn
Speaker 1: five was the only vehicle that the US had that
Speaker 1: would have that capability of actually getting someone to the moon.
Speaker 1: The Soviet counterpart to the Saturn five was not an
Speaker 1: R seven variant. It was a launch vehicle called the
Speaker 1: N one. It was a super heavy lift launch vehicle
Speaker 1: and had three stages. The Soviets wanted the INN one
Speaker 1: to deliver cosmonauts to the Moon during the Space Race,
Speaker 1: so this was gonna be the launch vehicle that would
Speaker 1: put cosmonauts to the Moon, hopefully beating the Americans in
Speaker 1: the process. The development of the N one started several
Speaker 1: years after the Saturn five development process had already begun,
Speaker 1: so the Americans were already ahead on rocket design, so
Speaker 1: the Soviets are behind. As a result, there was a
Speaker 1: ton of political pressure to rush through the design and
Speaker 1: production of the launch vehicle, and there was a lack
Speaker 1: of funding to do it too, so it was the
Speaker 1: worst of all worlds. Uh. This ended up including a
Speaker 1: design for the most powerful first stage rocket ever constructed.
Speaker 1: The designer of the N one was Sergei Koraev, but
Speaker 1: he died during a surgical procedure in nineteen sixty six,
Speaker 1: which was kind of in the middle of the process
Speaker 1: of developing the INN one that caused further problems in
Speaker 1: that whole development process. Obviously, there were only four test
Speaker 1: launches held for the N one, and every single one
Speaker 1: of those test launches resulted in failure. The second one
Speaker 1: resulted in a launch pad explosion so spectacular it entered
Speaker 1: the history books as the ninth largest non nuclear man
Speaker 1: made explosion. It was equal to the detonation of a
Speaker 1: kilo ton of T and T. So the project was scrapped.
Speaker 1: No one outside the Soviet Union would even learn about
Speaker 1: this until the Soviet Union itself collapsed. It was finally
Speaker 1: revealed in the late nineteen eighties after the Soviet Union
Speaker 1: had collapsed. So for for more than a decade, more
Speaker 1: than two decades, the United States had no idea that
Speaker 1: this was going on over at the Soviet Union, or
Speaker 1: at least very little confirmed idea of it. The Space
Speaker 1: Shuttle program, which I'm going to talk about in our
Speaker 1: next episode, had its own launch vehicle. One of the
Speaker 1: interesting things about that vehicle is that the Space Shuttle
Speaker 1: would be attached to an external tank. And also attached
Speaker 1: to this external tank, we're a pair of solid fuel
Speaker 1: rocket boosters, and those boosters could be recovered and reused.
Speaker 1: The external tank could not be reused, so it was
Speaker 1: not designed to be recovered. The tank was essentially just
Speaker 1: a fuel tank. So the shuttle itself had three main engines,
Speaker 1: and the external tank would provide fuel to those three
Speaker 1: main engines. Those engines would ignite it left off, and
Speaker 1: the two solid fuel rocket boosters would ignite at liftoff.
Speaker 1: Once the solid fuel rocket boosters had burned through, they
Speaker 1: would jettison from the external tank, fall back to Earth
Speaker 1: and get recovered for reuse. And then the Space Shuttle
Speaker 1: would eventually jettison the external tank as it was heading
Speaker 1: up toward orbit. The external tank would not be reused.
Speaker 1: But I'll talk more about the Space Shuttle in our
Speaker 1: next episode, and I'll also use that time to talk
Speaker 1: a little bit about the private launch vehicles that were
Speaker 1: created by SpaceX. I was going to do it in
Speaker 1: this episode, but these shows are running kind of along
Speaker 1: because I get gabby about all right, let's be honest,
Speaker 1: I get gabby about everything, but I I get particularly
Speaker 1: gabby about space stuff. And I know that's the case.
Speaker 1: So we're gonna save that SpaceX discussion for the end
Speaker 1: of the next episode. That's when we'll talk about the
Speaker 1: Space Shuttle program. That will be the conclusion of the
Speaker 1: space block of content, and then we'll switch gears or
Speaker 1: we'll change navigation to go to some new destination. If
Speaker 1: you guys have suggestions for what I should talk about
Speaker 1: an upcoming episodes of tech Stuff, send me an email.
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