Rocket Engine Nozzle

We just learned about Gas Rocket Propellants.

Another part of rocket science is the Rocket Engine Nozzle.

When the rocket propellant is burning up coming out of the rocket, the nozzle makes it so that it pushes out very fast and very strong, by putting some pressure right at the end of the rocket.

This is kind of like putting your finger over the end of a water hose, to make the water spray farther.

The shape and size of the nozzle is very important.
It has to be just the right size to get the most thrust and use up just the right amount of fuel.



(from: wikipedia - rocket engine nozzle)


Kid Facts - Blast from the past: Boring

Gas Rocket Propellants

We just learned about the Solid and Liquid Rocket Propellants.

Another type of propellant is Gas Rocket Propellant.

This type of propellant is the easiest to control the exact amount of fuel burned and the exact amount of thrust created.
To keep the gas stored safely and under pressure, the fuel tank in the rocket has to be very heavy, so gas is not usually used for the bigger rockets.
Gas has been used the most for little rockets that just change the direction of a rocket to the left or right.
Small rocket thrusters called Vernier Thrusters were on the sides of rockets like the SM-65 Atlas, to help it go in the right direction.


(from: wikipedia - vernier thruster)


Kid Facts - Blast from the past: Swarf

Liquid Rocket Propellants

We just learned about the Solid Rocket Propellants.

Another type of propellant is Liquid Rocket Propellants.

These can be made up of liquids like gasoline, kerosene or alcohol that are liquids at regular temperatures.
They can also be things that are liquids at really cold temperatures like liquid oxygen, or liquid hydrogen.

The good thing about liquid propellants is that they are lighter than solid ones, so a rocket doesn't have to try as hard to push itself along.
The bad thing is that sometimes they have to be stored very cold in a very high pressure container, and sometimes the liquids can cause problems and eat away at the metals and rubbers that they are stored in.

The first person to make a liquid fueled rocket was Robert H. Goddard, who used gasoline and liquid oxygen to launch a rocket in 1926 in Massachusetts.


(from: wikipedia - robert h. goddard)


Kid Facts - Blast from the past: Threading

Solid Rocket Propellants

We just learned that Rocket Propellant is the fuel that pushes a rocket along, and they can be solid, liquid or gas.

Solid Rocket Propellants are made up of a few different types of chemicals all mixed together.
Some parts of the mixture are to make a big explosion that will push the rocket along.
Other parts are soft and sticky almost like dough that help hold all the explosive stuff together.
Different chemicals will make bigger explosions or burn longer or hotter, so the rocket scientists have to pick the right kind of propellant for the right job.

Solid propellants are easier to store than liquid or gas, because they don't leak out much.
Also some liquid or gas propellants can eat away at the rocket tanks or rubber seals holding it in.

Solid propellants are heavier than liquid or gas, and a rocket with the same amount of liquid or gas would get more power and weigh less.
Sometimes the solid propellants can even get cracks or bubbles in the mix.
If you think about it like a big ball of playdough, any of the parts that aren't smooth, or any folds in the middle that have air pockets would cause problems.

The NASA space shuttle used two rockets with solid propellant, called the "Space Shuttle Solid Rocket Boosters (SRBs)"
At the time they were the most powerful solid rocket motors ever flown, and the two of them together weighed 2.6 million pounds.


(from: wikipedia - space shuttle solid rocket booster)


Kid Facts - Blast from the past: Skivving Machine

Rocket Propellant

Let's learn a little more about Rockets!

One thing that all rockets need is something called propellant.

This is the fuel used to push a rocket through the air.
Propellants can be solid like gunpowder, liquid like water, gasoline or liquid oxygen, or they can be a gas, like compressed nitrogen, or just pressurized air.

When the rocket is started, the propellant shoots out of the rocket at a super fast speed, pushing it along.
So this could be just a long skinny water balloon that shoots out it's water, or it could be a fireworks bottle rocket that burns up it's powder and shoots fire out the back.

The propellant is the stuff inside the rocket that makes the rocket go.


(from: wikipedia - ammonium perchlorate composite propellant)


Kid Facts - Blast from the past: Hobbing

Rockets

We've learned a whole lot about earthquakes.
Everything from tectonic plates, to faults, to aftershocks and the Richter scale!

Let's learn a little about rockets!

Usually when people are talking about rockets, they mean the ones that fly up into the air and go into outer space.
A rocket really just means something that uses fuel in an engine to push itself forward.
So this could be a rocket on the back of a car, a rocket pushing a train, or even a rocket jet backpack!
Even a water balloon filled with air or water that flies around when it is let go is a type of rocket.

Some people think the science of learning about rockets is so hard,
that there is a saying when you want to say something is easy:
"it's not rocket science!"


(from: wikipedia - rocket)


Kid Facts - Blast from the past: Milling Cutter