The numbers
- What it is
- A vehicle that carries a load into orbit
- How many stages
- Usually from two to four
- Where the load is
- Only in the tipThe rest is fuel
How it happens, step by step
Gas blasts out
The engine burns the fuel and blasts scorching gas out of just one end at very high speed.
The rocket moves
By throwing material out one way, the rocket is pushed the opposite way. No air is needed.
Lighter as it climbs
As it burns its fuel the rocket gets lighter, so it speeds up more and more.
A stage drops off
When a tank is empty it is let go: carrying the useless weight along would cost a fortune.
Into orbit
The last stages push the load up to the speed it needs to stay in orbit without falling back.
To get an idea
What you see on the launch pad is almost all fuel: the load takes up only the tip.
Empty stages are let go during the climb, because carrying them would be useless weight.
Fun facts
These are not in the book: there was no room on paper.
Almost all the rest of the rocket is there only to lift itself and its own fuel.
Launchers are split into stages, usually two to four, let go one after another.
To stay in low orbit, climbing is not enough: you also need an enormous sideways speed.
The agreed border of space is about ninety miles above the ground.
A rocket also gets faster because, as it burns, it keeps getting lighter.
The useful load can be a satellite, a probe, a capsule with astronauts, or supplies.
Test yourself
The first question is the one printed under the QR code, with the answer the book did not give. The other four only exist here.
Question 1 of 5★ is the one from your book
What does a rocket push against?
Question 2 of 5
Where is the load to be carried into orbit?
Question 3 of 5
Why is a rocket split into stages?
Question 4 of 5
Is climbing high enough to stay in orbit?
Question 5 of 5
Why does the rocket keep speeding up?
Riddles
What you see on the launch pad is almost all tank: the thing I really have to carry up there is all in my tip. What am I?
I come apart as I climb and drop my empty pieces, because carrying them would be a waste. I reach the top much shorter than I was when I left. What am I?
Try it yourself
Stand on a skateboard or sit on a rolling chair and throw something heavy away: you will move the opposite way.
Watch a launch video and count the moments when something breaks off and falls: each one is a stage that has finished its job.
The words
- payload
- What the rocket has to carry into orbit: its real reason for being.
Sources: Wikidata (Q697196), Wikipedia (Vettore spaziale).