Rockets and Space for Young Rocketeers

By Richard Newlands

If you want to get into Space, how do you go about it? Space is only 62 miles away so why is it so hard to get there?
The science of the forces and energies rocket scientists deal with are clearly explained with easy-to-follow diagrams. You’ll find out how a rocket gets the power to overcome gravity and Drag to get into Space. You’ll learn how to steer and stay alive while you’re up there and various ways to design a spacecraft so it gets you back safely. The many illustrations include innovative Spaceships such as Virgin Galactic’s SpaceshipTwo.
To get you started with building and flying rockets, there is a practical step-by-step guide to launching a scale model using Estes rocket motors. Tips from experienced rocketeers will get your model rocket flying high and help you get it back in one piece.
The final chapter is more challenging: it’s full of in-depth rocket science where you learn how to design and test a large rocket engine capable of getting you into Space!

• Language: English
• Publisher: Lulu.com
• Release date: Mar 4, 2017
• ISBN: 9781326965525

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Rockets and Space for Young Rocketeers

Rockets and Space for Young Rocketeers Epub edition

Richard M. Newlands

Copyright

All of this work is copyright 2017 Richard M. Newlands apart from illustrations credited at the end of the book.

All rights reserved: no part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning, or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act, without the prior permission of the copyright owner.

ISBN: 978-1-326-96552-5

Dedications

For all the rocketeers who taught me rocketry, especially the late John Stewart, John Bonsor, and John Pitfield. And for all the gentlemen at Southampton University who taught me rocket science.

Thanks to my rocketry friends at the United Kingdom Rocketry Association (www.ukra.org.uk) who I bounced ideas off and who gave me suggestions for corrections to put into this book, including John Bonsor of ‘Rockets to go’ schools workshops for the inclusion of his model rocketry tips.

Thanks to Adrian Hurt for the use of his rocketry photos.

Thanks to Helen for her support, and book writing and editorial experience.

About the author

Rick ‘the rocketeer’ Newlands has been interested in Space travel since childhood. He’s been building and flying rockets since he was 14 when he decided that he’d only ever use his rocketry for peaceful purposes.

He graduated with an Honours degree in Aeronautics and Astronautics from Southampton University, where he studied spacecraft design and rocket science and engineering. He also studied a little quantum physics with the Open University.

He’s chairman of the Aspirespace rocket engineering society (www.aspirespace.org.uk), a member of the British Interplanetary Society and the Scottish Aeronautics and Rocketry Association, and a founder member of the United Kingdom Rocketry Association (www.ukra.org.uk).

He’s also a technical advisor for several cool Space projects such as Reaction for M.E. www.reactionforme.org.uk

Though he hasn’t yet flown in a spacecraft, he spends a lot of his time working out how to build his own one someday, if only he could get someone to give him the money to do it!

Introduction

Man must rise above the Earth – to the top of the atmosphere and beyond – for only in that way will he fully understand the world in which he lives. The famous thinker Socrates said this in ancient Greece over two thousand four hundred years ago, and he was absolutely right.

Fifty years ago nobody had ever left planet Earth. Now ordinary people are thinking about ways of getting themselves into Space. Doesn’t everybody want to be an astronaut? I certainly do!

Technology is improving all the time, so building spacecraft is getting easier. Your mobile (cell) phone has more computing power than the computers used to send men to the Moon in the 1970’s.

Most books about Space just tell you what other people have built; they don’t expect you ever to go into Space yourself. This book does, it’s a guide on how to start to design your very own spacecraft that one day you might fly in!

You’ll learn that getting into Space is extremely hard because gravity is so strong, but fortunately there are ways of building spacecraft that can battle gravity and win.

To get into Space you need tools, and one of your most useful tools is science.

Not too much science, only what rocket scientists need to build spacecraft.

As part of this rocket science you’ll discover that there are forces that can help you get into Space, and ones that you’ll have to fight.

To build spacecraft you’ll have to find out how a rocket engine works, and you’ll discover that some work better than others. The rocket is used to give your spacecraft enough oomph to get it into Space, and you can also use rockets to steer spacecraft.

You’ll discover that staying up in Space involves a trick, otherwise you’ll fall straight back down to Earth.

You’ll find out how to stay alive in Space, what your body needs to breathe and how to stop yourself exploding!

You’ll learn how to get back home in one piece as you plunge into the atmosphere from Space and need to slow down before you hit the ground.

You’ll learn how to build a fully-working model spacecraft as your first step to building something bigger.

Then at the end of the book you’ll learn in great detail how a rocket engine works, and we’ll design one to get you into Space!

Chapter 1:  Why getting into Space is hard

What is Space?

Space is mostly nothing. None of the air that surrounds us here on Earth, no ground, zilch. There’s nothing to walk on or push against in Space so moving around is difficult.

Space is almost completely empty. The distances between stars or planets are incredibly vast. If you were magically transported to just anywhere in the Universe, the chances of you ending up near a planet are billions to one against.

The beauty of Space is this emptiness, because there’s nothing to obscure our view. In any direction we can see for trillions of miles. With just our eyes we can see stars in our Milky Way galaxy, and we can certainly see most of the planets in our solar system.

Where is Space?

Space starts where Earth’s atmosphere stops: 100 kilometres (= 62 miles) above your head.

That’s not very far away; you can drive 62 miles along a road in less than an hour using a small can of petrol (gasoline).

So why is it so difficult to go 100 kilometres up instead of 100 kilometres along?

The reason is gravity:

Gravity

To move something along, you just have to put wheels on it and get it rolling, but to move something upwards, you have to battle with gravity.

Gravity is the thing that makes things fall down: When you knock a pencil off a table, gravity is the thing that makes it fall to the floor.

Gravity causes everything in the Universe to pull together as if everything were a magnet. The bigger the thing, the stronger the pull.

Our Earth is huge, so it pulls really hard. If the Earth were just a bit bigger it would pull so hard we’d never be able to get off it, we can barely manage it as it is!

We have to beat this pull to get off the Earth.

Our Earth’s gravity acts as if it were trying to pull us towards the centre of the Earth. That’s why people in Australia, which is on the opposite side of the Earth from Britain, don’t fall off even though they’re upside-down compared to us.

So you have to think a bit about what you mean as ‘up’. Up really means outward from the planet.

Before the 1600’s, when scientists tried to understand gravity, they thought that things would naturally be sucked towards the centre of the Universe as if it were some sort of giant plughole.

Back then it was also thought that the Earth was at the centre of the Universe, therefore falling things would naturally fall toward the centre of the Earth, which was downwards to us humans standing on it.

Then in the early 1600’s a man called Galileo made his own telescope and pointed it at the night sky, so he could study the other planets in our Solar system. Galileo didn’t invent the telescope, we don’t know who did. The Vikings made lenses over 1000 years ago, but Galileo was (as far as we know) one of the first people to point a telescope at the night sky and then tell everybody what he saw by writing a book about it.

He saw that gravity didn’t just work on Earth, but on other planets too: it was causing moons to go round and round Jupiter. Without gravity the moons would just fly off into Space.

If gravity acted on other planets as well as Earth, then gravity couldn’t be to do with being the centre of the Universe at all. In fact, as Galileo watched the planets move around, he realised the Earth wasn’t the centre of the Universe anyway. Galileo became certain that the planets all circled around the Sun, just as an earlier astronomer called Copernicus had suggested. (Few people had wanted to believe this at the time, but actually it’s true.)

Galileo correctly thought that gravity was like magnetism in that it pulled stuff together. (Although unlike magnetism, nobody’s yet found gravity that pushes stuff apart.)

100 years later, a Scientist called Isaac Newton took Galileo’s ideas and worked out how strong Gravity is, and exactly how it affects the planets.

Isaac Newton worked out many other things useful for spaceflight, so I’ll be mentioning him many times later on. You may have heard the story that it was a falling apple that got Newton interested in Gravity. Actually, it was the Gravity of the Sun dramatically changing the course of a comet that flew very close to the Sun that got his attention.

How far out does Gravity work?

Some folk get confused when they hear about weightlessness in Space, and think that gravity stops when you reach Space. It most certainly doesn’t, I’ll explain about weightlessness later.

In fact, Earth’s gravity has a noticeable effect on planets at the opposite side of our Solar system, millions of kilometres away. So it’ll certainly affect your spacecraft in Space near the Earth.

So how do you combat Gravity?

Gravity acts as if it were a force. The only way to beat it is to generate your own strong force.

What's a force?

A force is a push or pull that tries to move something.

In Star Wars, the 'force' is a mysterious power that Jedi Knights have to push, pull, or throw things without touching them.

If your family loses their house-keys and can't get into the house, dad may have to 'force' the front door, which means kicking the door down.

A 'force 10' wind is a howling gale with the strength to blow the roof off a house.

Instead of saying, My alarm clock woke me up too early this morning, so I threw it out the window, a scientist might say, My alarm clock malfunctioned, so I exerted a force on it strong enough to send it out of the window.

Scientists measure forces in Newtons, named after Isaac Newton. (If anyone tries to tell you that force is measured in kilograms, they’re very wrong!)

You need to make a force to launch your spacecraft, and you have to aim this force in the opposite direction to gravity to beat it. Gravity acts like a downward force, so your force has to go upwards.

So you can see that when you talk about a force, you must always say in what direction the force pushes. The direction is very important, because if I push you backwards instead of pushing you forwards, you’ll move in a totally different direction.

So always think about what direction the force is pushing (or pulling). To show the direction of a force we often draw the force as an arrow, which is called a force vector. The shaft of the arrow shows the direction, and this direction is called the line of action of the force.

How much force do you need?

You need to make a force that’s stronger than your spaceship’s weight.

What exactly is weight?

What is weight, and what is mass?

Your spacecraft has weight, and it also has mass. These are related but are not the same.

Mass indicates the number of atoms something contains, which won’t ever change unless you cut it, and is measured in kilograms. (Some atoms have more mass than others, such as the very massive Uranium atoms.)

5 kilos of bananas is 5 kilos of bananas whether they're in a shop, or out in Space. Gravity doesn’t change mass.

What’s an atom?

Everything, even something that seems solid like metal, is made up of billions of incredibly tiny parts called atoms, which are pretty well indestructible. They don’t break, or melt.

Although an atom is far too small to be seen even with a microscope, (so nobody knows what they look like), you know they’re there by the way they behave as a group. You can think of atoms as a large pile of tiny balls that like to stick together.

Weight and gravity

Earth’s gravity pulls every atom (so that's everything with mass) down to the ground.

This pull that holds things firmly on the ground is the force we call weight.

So the weight of your spacecraft depends upon how strong the gravity is around it and how much mass it has:

Scientists and Engineers understand that weight is a force so they measure it in Newtons. (It was agreed internationally that everyone should measure weight in Newtons.)

On the surface of our planet Earth, gravity has a strength of just less than 10 (alright, 9.81, but it depends where you live). So the weight of anything here on Earth is just under ten times its mass.

For example, on Earth, a spacecraft with a mass of 600 kilograms weighs

The Moon's gravity, however, is six times weaker than Earth’s gravity, so a mass of 600

kilograms weighs only:

on the surface of the Moon.

The mass of the spacecraft hasn’t changed but its weight has.

An asteroid’s gravity is very weak. If you landed the 600 kilogram spaceship on an asteroid it might weigh only 10 Newtons: you could lift it!

As you can see, in Space, the difference between mass and