Star Tracker

We just learned about the Accelerometer.

Another guidance system that rockets can use is the Star Tracker.

When a rocket is way up in the sky, it might not be able to talk to any of the computers on the ground to find out where it is, especially if there are a lot of clouds or bad weather.

But if the rocket is up above the clouds and it is dark, the rocket can use cameras to look up into space and see the stars.
These stars can be compared to a star chart that says where each star is, and it can use this chart to keep itself on course, whether it's going to the moon, outer space, or even another planet!


(from: wikipedia - star tracker)


Kid Facts - Blast from the past: Numerical Control - CNC

Accelerometer

We just learned about the Altimeter.

Another part of rocket science is the Accelerometer.

This is something in the rocket that tells the rocket how fast it is accelerating.
This isn't the same as it's speed, which is just how fast it is going.
Acceleration is the difference in speed over time.

So think about it like if you are walking, and then you are jogging, and then you are running as fast as you can.
When you switch from walking to jogging, there is a difference in speed, and it however long it takes you to get from walking speed to jogging speed is the acceleration.

Gravity is another way to think about acceleration.
If a rock is dropped off of a tall building, it starts falling slowly, but then gets faster and faster, and by the time it hits the ground could be going fast enough to really hurt if it crashed into something.

The difference in how fast it is falling every second is the acceleration.
That is what the accelerometer measures, so that the rocket knows how much faster it is getting every second.



(from: wikipedia - accelerometer)


Kid Facts - Blast from the past: Plasma Cutting

Altimeter

We just learned about GNC - Guidance Navigation and Control.

One type of tool used to help navigation is an Altimeter.

This measures the pressure in the air to figure out how high up off the ground a rocket is.
When a rocket is close to the ground it has higher air pressure, and when it goes further up off the ground, the air pressure gets less and less.

With an altimeter inside the rocket's controls, the rocket can tell how high up in the sky it is.



(from: wikipedia - altimeter)


Kid Facts - Blast from the past: Water Jet Cutting

GNC - Guidance, navigation and control

We just learned about Gimbaled Thrust.

After a rocket is launched, it needs to be guided to make sure that it goes to the right place, whether that's outer space or just up into the atmosphere.

This is called Guidance, navigation and control, sometimes shortened to just GNC.

GNC is the science of how to control a rocket after it's been launched up into the air.


(from: wikipedia - guidance, navigation and control)


Kid Facts - Blast from the past: Electrical Discharge Machining

Gimbaled Thrust

We just learned about how Rocket Thrust Vectoring is changing the direction the rocket is going using thrust in different dirctions.

Another part of rocket science is Gimbaled Thrust.

This is a way for a rocket to tilt its nozzle to change the direction of the thrust for rocket thrust vectoring.

When the nozzle is tilted, it sends the rocket in a different path.


(from: wikipedia - gimbaled thrust)


Kid Facts - Blast from the past: Stamping

Rocket Thrust Vectoring

We just learned about the Fire Arrow.

Another part of rocket science is Thrust Vectoring.

When a rocket is flying up in the sky, there needs to be some way to steer it.

Sometimes rockets are built with a nozzle at the end that can be moved around to thrust in different directions, and sometimes they are built with extra rocket propellant tanks on the sides to give extra thrust to steer it.

Thrust vectoring really just means steering the rocket by changing where the thrust is going.


(from: wikipedia - thrust vectoring)


Kid Facts - Blast from the past: Bending

Fire Arrow

We just learned about how Specific Impulse measures how a rocket works.

Some of the first rockets that were made came from China over a thousand years ago, after the invention of gunpowder.

These were known as Fire Arrows.

At first people just had the idea to tie an explosive ball of gunpowder to the arrow that would blow up after the arrow was shot with a bow.
Later on someone figured out how to use the gunpowder as a solid propellant for the rocket in a wooden tube as the propellant tank, and use the burning of the gunpowder to thrust the arrow up higher and farther.


(from: wikipedia - fire arrow)


Kid Facts - Blast from the past: Burr

Specific Impulse

We just learned about Rocket Engine Thrust.

Another part of rocket science is called the Specific Impulse.

This is a way for scientists to measure how fast a rocket moves along, combined with how fast it uses up it's fuel as the rocket engine is blasting off.

The rocket can only burn up so much fuel before it runs out, so the more thrust the rocket for every little drop of its fuel really matters!


(from: wikipedia - specific impulse)


Kid Facts - Blast from the past: Grinding

Rocket Engine Thrust

We just learned about the Rocket Engine.

Another part of rocket science is the Thrust.

We learned that a rocket has propellant in a tank, and an engine that burns up that propellant and pushes the burning fuel out the back of the rocket at the nozzle.

As the fuel is being burned and pushed out of the nozzle, the rocket is pushed along through the air.
That push is called THRUST.

Some rocket engines have a lot of thrust and make rockets go very fast, blasting off into outer space.
Others only have a little bit of thrust, but they are very careful about exactly how much thrust they make in the right direction, like for steering a rocket.

Scientists have to know exactly how much thrust a rocket will have, so they know how much propellant they need, and how big of a tank to use and the shape of the nozzle.


(from: wikipedia - rocket engine)


Kid Facts - Blast from the past: Hole Saw

Rocket Engine

We just learned about the rocket's Combustion Chamber.

So we know about the rocket propellant, the propellant tank, the combustion chamber and the nozzle.

When these pieces are all put together it makes the Rocket Engine.

The engine is all of those pieces working together to push the rocket along up into the sky.


(from: wikipedia - rocket engine)


Kid Facts - Blast from the past: Twist Drill Bits

Combustion Chamber

We just learned about the Rocket Propellant Tank.

Another part of a rocket is the Combustion Chamber.

We've learned about the propellant tank that holds the propellant, which is the fuel to make the rocket blast off.
Usually with solid propellants, the propellant tank is the same place where the fuel burns up and pushes the rocket along.
With liquid or gas propellants, the tank is usually separate, and there are tubes and pipes that bring the propellant into another area where the fuel burns up and pushes the rocket along.

This tank where things are burning up is called the Combustion Chamber.
Combustion basically just means burning up or even exploding.


(from: wikipedia - combustion chamber)


Kid Facts - Blast from the past: Drill Bits

Rocket Propellant Tank

We just learned about the Rocket Engine Nozzle.

Another part of a rocket is the Propellant Tank.

This is where the rocket fuel goes, and is usually very large.
The tank used for the space shuttle rocket was over 150 feet tall, and weighed over 58,000 pounds empty, but over 1,680,000 pounds when filled up.


(from: wikipedia - space shuttle external tank)


Kid Facts - Blast from the past: Drilling

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

Speleoseismite

We just learned about the seismite.

Another part of earthquake science is Speleoseismite.

In caves there are things called stalagmites that grow from the floor, and stalactites growing from the ceiling.
Sometimes during earthquakes these break, or sometimes cave ceilings collapse.

These broken or tilted rock growths are the speleoseismites, and they can be used to study earthquakes that happened a long time ago.


(from: wikipedia - speleoseismite)


Kid Facts - Blast from the past: Milling

Seismite

We just learned about the Mercalli Intensity Scale.

Another interesting thing about earthquakes is Seismite.

This is a type of rock formed when an earthquake causes a bunch of sedimentary layered rocks to get messed up and deformed.

Sedimentary rocks usually look like a bunch of sideways lines stacked on top of each other.
Sometimes when an earthquake happens, the lines get squished around and sometimes look like bubbled up rocks.

That squished up rock is called seismite.


(from: wikipedia - seismite)

Kid Facts - Blast from the past: Lathe - Carriage