1. Rocket Engines Liquid Propellant Solid Propellant Hybrid Nuclear
Mono propellant
Catalysts
Bi-propellant
Solid Propellant
Grain Patterns
Hybrid
Nuclear
Electric
Performance
Energy
Safety
Simplicity
Expanding Gases
Thrust Termination
Restart

2. Rocket Propulsion Liquid Rocket Engine Propellants Oxidizer Fuel
Combustion Chamber
Throat
Nozzle

3. Newton’s Laws m = F a m a = F F = ma
The force required to accelerate a body is proportional to the product of the mass of the body and the acceleration desired.
m = F a m
a = F
F = ma

4. . Rocket Thrust Thrust is produced by the expanding propellants.
There is thrust from the difference between the ambient pressure and that of the exhaust gases at the nozzle exit (Pressure Thrust) and from the momentum of the propellants (Momentum Thrust).
Total Thrust = Momentum Thrust + Pressure Thrust
Nozzle Area times
pressure differential
Propellant Mass Flow
times Velocity W . g Ve
F = Ae ( Pe - Pa)

5. Exhaust Plumes and Nozzles
Pexhaust < Pambient
Under Expanded
Pexhaust = Pambient
Ideal Expansion
Pexhaust > Pambient
Over Expanded

6. Expansion Ratio
Ratio of the nozzle exit area divided by the area at the nozzle throat. At Ae
x =
Throat
Exit

7. Specific Impulse
A measure of the energy in the propellants and of the efficiency of the rocket engine design
Specific Impulse is the ratio of the Thrust (Force) produced divided by the weight rate flow of propellants W . F
Isp =

8. Mass Ratio of a Vehicle
Mass Ratio is the ratio between the booster mass before
the rocket engine burn divided by the booster mass
after rocket engine burn.
MR = mi mf
The Mass Ratio for a multistage rocket is the product
of the Mass Ratios of all the stages, i.e.
MROver All = MR1 x MR2 x MR3 x …x MRn

9. Thrust-to-Weight Ratio
Measure of booster or stage design and manufacturing technology.
The higher the thrust-to-weight ratio the faster the vehicle will accelerate
The initial acceleration of a vehicle in “g’s” equals
Y =
Thrust
Vehicle Weight = F W
a = ( Y - 1 )

10. Ideal Rocket Equation
The ideal velocity change ( DV ) for each stage of a rocket is a function of the mass ratio ( MR) of the stage and the specific impulse ( Isp ) of the rocket
Ideal means you do not consider gravity changes, drag, or rotating Earth
DVi = Isp x g x ln MR