Science & Technology

Rockets: How Rockets Work

Chris Hadfield

Lesson time 20:42 min

Chris explains the functions of the basic parts of a rocket, the physics of launching one beyond the atmosphere, and how rocket design has evolved from mission to mission.

Chris Hadfield
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So how does a rocket work, anyway? How is it that we get off the surface of the world? Let's just start with an airplane. We're all pretty familiar with how an airplane works. There's an engine inside. We carry fuel inside the fuselage. And the wings hold us up. The oxygen that we're going to burn in the motor is just coming from the atmosphere. So the air comes in the front of the motor here. It mixes with the fuel that we brought. And then it comes spewing out the back, pushes us along. And then the wings are just holding us up against gravity that's holding us down. But what do we do when we want to go this way? What do we need to change for a rocket to work? Well, let's choose a very simple rocket design, this one. It's simple but it will work. So the real purpose of a rocket, of course, is to take something up to space. So in this case we'll say it's this capsule on the top. So one of the key components of a rocket is the thing that you're carrying. But then you need fuel, just like in an airplane. So somewhere inside this, there's a fuel tank. But the big difference of a rocket is, you're going to get above the air. You're not going to be able to get the free oxygen out of the atmosphere that an airplane gets. So you're going to have to bring the oxygen with you in order to be able to generate the power that's going to push you away from the world. So inside every rocket there needs to be not only fuel but also oxygen. And so that's why so many, even the cartoon rockets like this one, they're all sort of bulbous shaped because they are in fact flying tanks, tanks of oxygen, tanks of fuel. We only need two more things. We have a thing to carry. We have the fuel and oxygen tanks. Then we need a place for the hot stuff to come out. And that's the back here. That's where the engine thrusts. And then we need some way to steer on the way up. And in this case we've got, even though it's a cartoon rocket, we've got these big aerodynamic fins that will allow us to steer. They're not going to work once we get up above the air. These will only help us steer when we're in the air. As soon as we're in the emptiness of space, you can wave your fins around all you want, but they're no longer going to have any air to push against, so you won't be able to point. So somehow you need to be able to actually control which way the exhaust is coming out so that you can continue to steer your rocket when you get up above the atmosphere. But that's essentially true of every single rocket-- something that carries, the fuel and oxygen supply, a way to steer, and where the hot stuff comes out. [ROCKET IGNITION] Let's look at one of the classic rockets, Saturn V. This is what took us to the moon. It looks like a really complicated, interesting, different kind of thing. It was huge. It was 360-odd feet tall, you know, 36, 37 stories tall, an amazing thing. But let's look at it the same as we did the cartoon rocket. It's got the thing t...

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Impossible things happen. At age nine, Chris Hadfield knew he wanted to go to space. He eventually went there three times, becoming a commander of the International Space Station. In his MasterClass, Chris teaches you what it takes to explore space and what the future holds for humans in the final frontier. Learn about the science of space travel, life as an astronaut, and how flying in space will forever change the way you think about living on Earth.


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Through his class, I got really inspired and motivated toward being astronaut. So far, it was a just dream for me, but now it changed to dream that be able to come true. Now I work at Air Force as a fighter pilot of F15 and I decided to be an astronaut in the future!

Wow! Great Class. Makes me want to do my best, and do great things!!

I love how Chris encouraged and inspired us, he opened my eyes to the possibilities of being part of the space exploration. I learn a ton about the tips and mentality to success from his experiences and that meant a lot to me. Thanks a lot Chris!!!

Is the best class i´ ve ever seen in my life, Chir explain things easy, I have learned a lot from him and I admire and have a lot of respect to him.


Victoria C.

So amazing to understand the vastness of space exploration and the terms Chris uses in order to explain this, how we go from not being earthlings anymore. Maybe I am wrong, I don’t think I truly understand, as not having the actual experience. Something only a small number of people truly get.


The information provided was like drinking from a firehose and my brain is just wanting more and more. This first season has placed the subject-matter into lens and framing for me that is just so digestible, practical and real. It's like when Neo get his first taste of The Matrix.

Ken C.

A good explanation of the basic components of a rocket. Exactly what Robert Goddard accomplished with his final flights. In rocket flight there is no "do-over". Chris is an excellent presenter.

David M.

Good effort to boil down an extremely complex undertaking and present it so simplistically; however, more props (and there are plenty of them out there) would have made this even better.

Tom D.

Very interesting. I do wonder though how it's possible for an unusable stage of the rocket to burn up returning back into the earths atmosphere? If it was possible to burn up wouldn't it have burnt up during the accent?

A fellow student

This is just a small gripe. My coworker is a bit of a skeptic when it comes to the moon landing. Thinking about sharing this, but I know he is going to question, “Why do you not have a scale model of the landing capsule?”

Ansh M.

Thank you so much Chris! I learned a ton about this topic. And im only 11! But you made it easy for me.

Chris L.

It's interesting, but pretty basic stuff for someone looking to learn something beyond a standard documentary on Netflix.

Suhaib T.

It’s been awhile since the last lesson but I’m finally back. I’m starting to realize this class is made for the lowest common denominator. Chris was quite elementary in his explanations. Not to say I didn’t benefit from this lesson. People approach me where I work for all things space related. This lesson will help me bridge that gap of understanding for my coworkers who are not well read on this topic. I liked the way Chris describes rockets as just flying tanks, one for the fuel and one for oxygen. Never thought of it that way. The fact that we don’t have a free supply of oxygen in space means we have to bring our own. Again he help me connect that basic concept. Chris describes a rocket launching as balancing a broomstick on your palm. Which is a really good analogy to rocket launches. The detail he gave on how thick the fuel line is on a rocket when compared to your vehicle put in perspective the scale of how massive a rocket is and what it takes to feed fuel to the engine (17” vs .25”). Also love the detail of how when the shuttle astronauts who are sitting on the launch pad can feel the engines gimbal before take off. Pretty cool. Somethings I want to point out is at 15:50 that was a Gemini capsule not an Apollo capsule. I don’t know why the producers thought space enthusiasts wouldn’t catch that. The other thing is that I wish Chris had more accurate models at his disposal. The models he used barely did the job. This series so far does a good job ending the lesson talking about the future. I’m glad they mentioned the Falcon 9 rocket. Chris said it was something new in rocket technology to see a landing pad next to a launch pad and that made me appreciate this new chapter of space exploration we are in even more.

A fellow student

Not going to lie, I bought all access just for this class, not because I want a ton of classes, but it seems a no brainer to pay double the cost of one class and get all classes, because there was no way I would have paid 90 bucks for just this lesson