Making & Creating: How Rockets Work 🚀🧑‍🚀

You're listening to Sleep Titan Science. You're listening to Sleep Titan Science. Did you know rockets have to reach 40,000 kilometers per hour just to break free from Earth's pull? What?

That's 40 times faster than a jet. Hello, friends, and welcome back to Sleep Tight Science, a bedtime show that answers your questions about science. We're continuing our Making and Creating series,

where we explore how people build and engineer amazing things, from chocolate bars to machines that can leave the planet. Tonight's topic was suggested by Ravid, who is 8 years old. Thank you for your questions about space and rockets, Ravid.

In this episode, we are going to try and answer the following question. How do rockets work? What makes them powerful enough to escape Earth's gravity and travel to space? We'll start with the challenge.

Why leaving Earth is so hard? Gravity pulls everything down. The atmosphere creates resistance, and you need to go incredibly fast just to break free.

Then, we'll explore the solution. how rockets work by pushing gas at one end to push themselves the other direction, and why they carry their own oxygen. Finally, we'll look at the engineering,

how rockets are built in stages that separate and fall apart, and how engineers test every part to make sure it works. You don't have to remember every word or every concept we share. It takes time to understand new things, and sometimes the science we share has big words and ideas.

It's okay. Try to remember this. Rockets work by pushing hot gas out the bottom very fast, which pushes the rocket up. Engineers have to build them strong enough, light enough, and powerful enough to reach the incredible speeds needed to escape Earth's pull.

Before we continue, here are some words to listen for. Gravity. The force that pulls everything toward Earth's center. Thrust, the pushing force that lifts a rocket Propellant, rocket fuel

Includes both the fuel that burns and the oxidizer that provides oxygen Combustion, burning fuel to create hot, expanding gas Stages Sections of a rocket that separate and fall away as fuel is used up

Escape Velocity The speed needed to break free from Earth's gravity About 40,000 km per hour or 25,000 miles per hour A quiet thank you to Etta and Arlo Paquin, age 9 and 7, in Minnesota for introducing our show.

And to all our wonderful friends who send in questions. You help us learn together. And thank you to all our listeners. Without you, we couldn't make this show.

Take a great big belly breath and imagine this. A rocket stands on a launch pad, tall and sleek, filled with fuel. Engines ignite. Flames and gas explode downward. The force builds, pushing, pushing, until slowly the rocket lifts.

Gravity pulls down, but thrust pushes up. The rocket rises faster and faster, climbing towards space. Ready to explore how humans engineered machines powerful enough to leave Earth? Let's get started.

Leaving Earth is hard. Really hard. And to understand why rockets are built the way they are, you need to understand the challenge engineers faced. The first challenge is gravity. Earth pulls everything toward its center.

That pull is what keeps you on the ground, what makes things fall when you drop them. If you want to leave Earth and go to space, you have to go fast enough that Earth's gravity can't pull you back down. That speed is called escape velocity, and for Earth, it's about 40,000 kilometers per hour, or 25,000 miles per hour. That's a pretty big number.

So to put that in perspective, a car on a highway might go 100 kilometers an hour or 60 miles an hour. A commercial jet flies at about 900 kilometers per hour or 560 miles per hour. A rocket needs to go more than 40 times faster than a jet just to escape Earth's pull. That's super fast.

The second challenge is the atmosphere. For the first 100 kilometers, or 60 miles or so, you're pushing through air. Air creates drag, which is friction that slows you down. The faster you go, the more drag pushes back.

This friction also creates heat, which is why rockets glow during launch. Rockets have to be streamlined, smooth sides, pointed nose, to cut through air as efficiently as possible. The third challenge is that you need continuous power. A rocket can't just get a running start and coast.

Gravity is always pulling, always slowing you down. You need engines pushing continuously until you reach the right speed and altitude. Only then can you turn off the engines and coast. And here's the tricky part. Fuel is heavy. The more fuel you carry, the heavier your rocket is.

The heavier you are, the more fuel you need to lift all that weight. Engineers had to find clever ways to solve this problem, and we'll see how in the next part. So, if you decided to make a rocket tomorrow, your challenge would be this. You would need to reach 40,000 plus kilometers per hour, push through the atmosphere, carry

enough fuel to do all of that, and don't make the rocket so heavy that it can't lift itself. have been dreaming about reaching space for a long time. The Chinese invented gunpowder rockets over a thousand years ago for fireworks and weapons, but those couldn't reach space.

In the early 1900s, scientists like Konstantin Tsiolkovsky, Robert Goddard, and Hermann Oberth worked out the math and science of how rockets could actually get there. The first object to reach space was a German V-2 rocket in 1944. In 1957, the Soviet Union launched Sputnik, the first satellite to orbit Earth.

In 1961, Yuri Gagarin became the first human in space. And in 1969, NASA's Apollo 11 landed astronauts on the moon. It took decades of work, thousands of engineers, and a lot of testing.