Most rockets have a nose or cone at the top, a body that
houses the fuel and fins at the base.
Rockets are usually powered by a chemical reaction
(explosion) within the rocket itself. This chemical reaction requires both fuel
and oxygen, both of which must be carried within the rocket.
The fuel and
oxygen are called the propellant. There are two types of propellant, liquid
propellant and solid propellant.
A solid propellant rocket is easier, simpler and cheaper to
make. However, these rockets are harder
to guide and control as once the chemical reaction is started it is hard to
stop.
A liquid propellant rocket is more complex and expensive to
make but the burning of the liquid fuel is allot easier to control.
A bit of history
The Chinese were the first to invent rockets when they
started filling bamboo tubes with gunpowder and lighting them.
Rocket science really began with an English man called Isaac Newton. He formulated three laws to explain the
physics of motion. These laws explain how rockets work!
Newton‛s 3rd Law of Motion states that every action has an
equal and opposite reaction!
To understand this law think of a balloon full of air.
If the balloon is untied and the air suddenly let out, it
will escape the balloon with such force that it will propel the balloon in the
opposite direction.
The force of the air leaving the balloon is called the
thrust! The thrust that powers the launch of a rocket comes from the force of
the gas (generated by the burning fuel) being ejected from the rear of the
rocket!
The first liquid propellant rocket was launched in 1926 by an American called Robert Goddard. He is considered the father of modern rocket science!
In 1969 Neil Armstrong and Edwin Aldrin became the first men
on the moon.
Armstrong and Aldrin traveled to the Moon in a rocket
called Saturn V. It was 100 metres tall and weighed more than 3,000 tonnes! It
was the largest rocket ever launched!
An Experiment to try at home
Make a stomp
rocket!
You will need... an empty 2L
plastic bottle, paper, insulation tape, a 1/2 inch PVC pipe, a length of rubber
tubing;
What to do… tape one end of
the rubber tubing to the neck of the bottle and tape the other end to one end
of the PVC pipe. Next make the body of the rocket by wrapping a piece of paper
around the PVC pipe and secure it with tape at the overlap. Remove the rocket
from the pipe. Cut four triangles of paper and attach to the body of the rocket near one end; these are the rocket
fins. Make a nose (cone shape) for the other end of the rocket and attach it
with tape. You are now ready to launch
your rocket. (Best to do this outside!).
Sit your paper rocket over the PVC pipe and place the 2L
bottle on the ground on its side. Stomp on the bottle and watch your rocket
shoot off!
This is what your stomp rocket should look like!
So what is happening?... when
you stomp on the bottle the air inside it shoots out through the tubing and the
pipe, forcing the rocket off the end of the pipe! Just blow into the pipe to
re-inflate to bottle to start again!
An Experiment to try at home
Make a teabag rocket
I have shared this one with you before, but for those of you who have not seen it I thought it would be a nice addition here.... a double for the Bank Holiday Weekend ;0)
If you try any of the experiments or have any comments or questions, please let me know in the comments below!
