1. Rockets 101 AIAA – March 2009 Theory of Rockets Dr. Eric Besnard California State University, Long Beach Project Director, California Launch Vehicle Education Initiative http://www.csulb.edu/rockets/

2. Rockets 101 AIAA – March 2009 2 How does a rocket work? Exercise 1: –Take a balloon and blow it up – Do not tie it –Release the balloon –What happens? Why? Exercise 2: –Take a cart with a pile of bricks on it –Stand on the cart and throw bricks backward –If there is no friction on the wheel, what happens? Why?

3. Rockets 101 AIAA – March 2009 3 Thrust This effect comes from conservation of momentum –Momentum: Definition: mass x velocity (speed) A truck at 40 miles per hour has more momentum than a car at 40 miles per hour A car at 40 miles per hour has more momentum than a car at 20 miles per hour –Newton’s first law of motion: When no external forces are applied on the object, momentum is conserved –Mass exits backwards at a certain speed or velocity –Therefore object moves forward at a speed which will conserve momentum: → THRUST is generated Rocket (large mass, “small” velocity) Gas (small mass, large velocity)

4. Rockets 101 AIAA – March 2009 4 Rocket flight Newton’s second law of motion: forces acting on the object will change the momentum of the object: F = m a –F: Sum of all forces –m: mass of object –A: acceleration of object Forces on our rocket: –Drag (air) –Weight (gravity) –Thrust (engine) Fins are added for stability of the rocket

5. Rockets 101 AIAA – March 2009 5 Rocket engines Generate high velocity gas by chemical reaction (burning) of propellants: –Something which burns: fuel –Something which carries oxygen: oxidizer Unlike aircraft engines which take the oxygen from the atmosphere (“air-breathing” engines), rocket engines carry their own oxygen so they can fly in space (where there is no atmosphere) LOX tank LH 2 tank Solid Rocket Booster Orbiter Types of propellants: –Solids. Ex: gun powder, Estes rockets –Liquids. Examples: Oxidizer: liquid oxygen, LOX (≈ -320 F) Fuel: liquid hydrogen, LH 2 (≈ -425 F) or kerosene –Hybrids: nitrous oxide (laughing gas) & rubber Propellant is burnt and accelerated with a nozzle

6. Rockets 101 AIAA – March 2009 6 A Really BIG rocket engine 5 F-1 engines were used on the Saturn V on its way to the Moon 1.5 million pounds each!

7. Rockets 101 AIAA – March 2009 7 Smaller rockets, same technology… Designed and integrated by Long Beach State students

8. Rockets 101 AIAA – March 2009 8 Aerospike rocket engine static fire test

9. Rockets 101 AIAA – March 2009 9 When something goes wrong…

10. Rockets 101 AIAA – March 2009 10 Prospector-4 flight

11. Rockets 101 AIAA – March 2009 11 A slightly bigger rocket: size for 20 lb to orbit!

12. Rockets 101 AIAA – March 2009 12

13. Rockets 101 AIAA – March 2009 13

14. Rockets 101 AIAA – March 2009 14 Your rocket Nozzle Solid propellant Ejection charge for deployment of recovery system Non-thrust delay and smoke tracking charge High thrust charge for lift-off and acceleration