Mysorean Rockets

We just learned about the Great Art of Artillery - First Part.

Another type of ancient rockets are Mysorean Rockets.

These were another type of rockets used as weapons by the people in India around 1780 AD when they were fighting against the people of Britain.

When the people of Britain saw these rockets, they went back home and brought the news about rocket science to Europe.


(from: wikipedia - mysorean rockets)


Kid Facts - Blast from the past: Doublet Earthquake

Great Art of Artillery, the First Part

We just learned about the rocket launch of Lagari Hasan Çelebi in the 1630s.

Another part of rocket hisory is the book Great Art of Artillery, the First Part (Artis Magnae Artilleriae pars prima) written in 1650 by a Polish-Lithuanian general named Casimir Siemienowicz who knew a lot about rockets.

His book talked about rockets used both for war and for fun, and talked about multi stage rocketse, wings for steering rockets, and batteries for rockets.

The book is called "The First Part" but no one has ever found a second part.
Some people believe that there were other scientists from that time who didn't want people knowing all of their secrets about things like rockets so they had him killed!


(from: wikipedia - casimir siemienowicz)


Kid Facts - Blast from the past: Blind Thrust

Lagari Hasan Çelebi

We just learned about the Bellifortis Rockets.

Another ancient rocket launch from history was the first manned rocket flight, by Lagari Hasan Çelebi in 1633 AD in Instabul, Turkey.

Lagari was famous for flying, and the legend of his flying says that he made a 7 winged rocket with gunpowder, and launched it in the air to celebrate the birth of the sultan's daughter.

Before he launched he said "O my sultan! Be blessed, I am going to talk to Jesus!"

After he landed in the water he swam back to shore and jokingly said "O my sultan! Jesus sends his regards to you!"

Some people think maybe this rocket wasn't real, but since it was so long ago no one can really tell for sure.


(from: wikipedia - lagâri hasan celebi)


Kid Facts - Blast from the past: Thrust Fault

Bellifortis Rockets

We just learned about the Shock Diamond.

For the history of rocket science, the inventions were made either for war, or for fun like fireworks.

There was a book called Bellifortis written by a German scientist named Konrad Kyeser around 1400 AD that talks about rockets.
It says how rockets were being used for war but also for fun like fireworks.

Because there were no pictures back then, some people made drawings of the rockets, but no one knows for sure what they looked like.
In this book there was a drawing of the famous Alexander the Great holding a big rocket.

Konrad's book talks about rockets that were launched in the air, rockets that floated on the water, or rockets that were tied on a string.
These rockets probably all used the solid rocket fuel of gunpowder to launch them along.


(from: wikipedia - bellifortis)


Kid Facts - Blast from the past: Aftershock

Shock Diamond

We just learned about the Multi-stage Rocket.

Another part of rocket science is the Shock Diamond.

When a rocket engine is pushing itself along, the burned up rocket fuel coming out of the nozzle is the exhaust.
This exhaust sometimes is coming out faster than the speed of sound, which is called supersonic speed.

When something is moving through the air it is making waves, and when it moves at supersonic speeds it makes these special diamond shapes in the exhaust called shock diamonds.

This is all because the waves that the exhaust is making are moving faster than the sound waves can move, so they overlap and make shapes that you can see.



(from: wikipedia - shock diamond)


Kid Facts - Blast from the past: Mainshock

Multistage Rocket

We just learned about a rocket's Lift.

Another part of rocket science is Multi Stage Rockets.

Sometimes when rockets are going to go into outer space, the rocket is split up into a few different parts that go off at different times.

The first part of the rocket burns up all of its fuel, then splits off and falls to the ground.
When it does this, the rest of the rocket is lighter, and it starts up another rocket engine that burns and thrusts it up higher.
Each one of these parts is called a stage.
These rockets can have anywhere from 2 to 5 stages, sometimes using different types of fuel, like liquid or solid or gas.


(from: wikipedia - multistage rocket)


Kid Facts - Blast from the past: Foreshock

Lift

We just learned about the Air Resistance, part of ballistics which is the science of the forces that move a rocket around.

Another part of ballistics is Lift, which is all about how the air flows underneath a rocket that helps it fly up.

You can feel lift if there is a strong wind and you put your hand out flat, the air will try to push your hand up like a kite.
The way you hold your hand changes how the wind pushes on you, and rockets can use small fins or wings to try and use lift to help them fly.


(from: wikipedia - lift (force))


Kid Facts - Blast from the past: Ring Fault

Air Resistance

We just learned about Ballistics.

One part of ballistics is Air Resistance, which is also called drag.

When the rocket is flying through the air, it is pushing the air out of the way.
The shape of the rocket can make a big difference for how fast it can fly through the air.

If you think about it like pushing your hand through the water, if you point your hand it will go in the water fast.
But if you use the open flat part of your hand and smack the water, your hand will be more like a paddle and you'll slowly push the water out of the way.

We don't think about it much for air, but it works the same way for rockets trying to push through the air.
So the front of the rocket has to have a pointed shape for it to fly quickly.





(from: wikipedia - drag (physics))


Kid Facts - Blast from the past: Listric Fault

Ballistics

We just learned about the Inertial Navigation Systems.

Another part of navigating rockets is the science of Ballistics.

This is all about the forces that are moving the rocket around, and what happens to the rocket because of those forces.

Usually there are 4 forces on the rocket:
1. Thrust from the engine
2. Gravity
3. Drag - which is like the air blowing against the rocket
4. Lift - which is like air blowing with the rocket


(from: wikipedia - ballistics)


Kid Facts - Blast from the past: Olique Slip Fault

Inertial Navigation System

We just learned about the Reaction Control System.

Another part of rocket science is an Inertial Navigation System, or just INS for short.

We've learned that accelerometers, gyroscopes and magnetometers are all sensors that can tell a rocket where it is going.
An INS is a computer that is hooked up to different sensors like these, and it steers the rocket the right way based on what the sensors tell it.



(from: wikipedia - inertial navigation system)


Kid Facts - Blast from the past: Dip-Slip Fault

Reaction Control System

We just learned about Attitude Control.

We've learned about a lot of different sensors to help the rocket control it's attitude.
And we've learned about things like gimbaled thrust that can help change it's path.

Another way a rocket can change it's direction is by using a Reaction Control System, or RCS for short.

These are usually small rocket engine thrusters on the sides or front of the rocket, that can give little pushes left, right, front or back to help steer the rocket.


(from: wikipedia - reaction control system)


Kid Facts - Blast from the past: Strike Slip Fault

Attitude Control

We just learned about the Inertial Measurement Unit (IMU).

A lot of the sensors we've been talking about are all part of Attitude Control.

This means controlling where the rocket is and which way it is pointing.
The attitude of the rocket is where the rocket is moving, whether it's up, down, left, right, forward back.


(from: wikipedia - attitude control)


Kid Facts - Blast from the past: Fault

Inertial Measurement Unit (IMU)

We just learned about the Airspeed Indicator.

Some of the tools we've talked about are things called Inertial Measurement Units or just IMU for short.

Inertia is the change in the rockets speed or direction, so the tools that we talked about like the gyroscope, magnetometer and accelerometer are all used to tell how the rocket is moving, so they are all IMUs.

IMUs all help measure things called Roll, Pitch and Yaw.

Roll is like when an airplane is still going forward in the air, but does a spin so it is flipped upside down, but still going forward.
Pitch is like when the airplane moves its nose to go down toward the ground or up toward the sky.
Yaw is like when the airplane isn't flying along and then turns left or right.

Different types of rockets use different IMUs depending on what kind of sensors they need, but they all are used to measure roll, pitch and yaw.



(from: wikipedia - inertial measurement unit)


Kid Facts - Blast from the past: Tectonic plates.

Airspeed Indicator

We just learned about the Spacecraft Magnetometer.

Another rocket guidance tool is an Airspeed Indicator.

When the rocket is blasting through the air, it can use this tool to figure out how fast it is going.
The Airspeed Indicator uses something called a pitot tube (pronounced PEE-toh) which is a tube that has some liquid in it.
As the rocket flies along the air flowing into the pitot tube puts pressure on the liquid, and the airspeed indicator uses that pressure to measure how fast the rocket is going.

If it is going very fast, there will be a lot of pressure.



(from: wikipedia - airspeed indicator)


Kid Facts - Blast from the past: Hypocenter

Spacecraft Magnetometer

We just learned about the Gyroscope.

Another tool used for navigation and guidance is a Spacecraft Magnetometer.

This uses a magnet that is wrapped in metal coils, with electricity running through the metal coils.
If there are other magnetic forces around, these electric coils will give off fields that can tell the rocket which way to go.


(from: wikipedia - spacecraft magnetometer)


Kid Facts - Blast from the past: Cross Peen Hammer

Gyroscope

We just learned about the Star Tracker.

Another part of rocket navigation systems is the Gyroscope.

Gyroscopes are sort of like a spinning top, with a few other circles on them.
The top is a circle shaped disc spinning around sideways, with a post in the middle, like an anchor for it.

There are usually three circle shaped frames, called "gimbals" around the spinning top.
On the very inside there is a circle holding on to the post for the top. This is the "inner gimbal".
Another circle is hooked onto that inner gimbal, and that is called the "outer gimbal".
The one on the outside of the outer gimbal is called the "outer ring".

If the disc in the middle is spinning, and you move the outer ring around, the inner gimbal and outer gimbal will move up, down or sideways, and the disc will stay straight up and spinning.
This might seem like magic, but really it's the same kind of science that keeps a toy top spinning on the ground, or helps you ride a bike.
The fancy name for it is "angular momentum", but it really just means a spinning wheel doesn't like to fall over, so for a gyroscope it makes the inner and outer gimbal move instead of falling over when you move the outer ring.

Rocket scientists figured out that if you hook the outer ring up to sensors in the rocket, you can tell when the rocket is tilting, and they can hook up the nozzle to a gyroscope to use the gimbaled thrust we learned about and steer the rocket back on course!

The science behind gyroscopes was discovered hundreds of years ago, and used to help steer ships on the water.
These days gyroscopes are even used in video games and cell phones, to tell the phone when it is being tilted!
The ones inside phones aren't spinning wheels though, they are microscopic sensors that move around when you move your phone.





(from: wikipedia - gyroscope)


Kid Facts - Blast from the past: Earthquakes

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