1. ROCKETS AND MISSION ANALYSIS

2. SOLID PROPELLANT ROCKETS
Solid fuel rockets rely on controlled explosion of a mixture of substances
Nearly a homogeneous material that is burned
Similar to gunpowder ~ (75% potassium nitrate, 10% carbon, and 15% sulfur)
Example: STS Solid Rocket Boosters:
Contain ammonium perchlorate as an oxidizer and aluminum as a fuel
Rest of mixture devoted to bonding two reactants
Once a solid rocket is ignited, can not be turned off

3. OVERVIEW: SOLID ROCKET COMPONENTS

4. SPACE SHUTTLE SOLID ROCKET BOOSTERS
SRBs are largest solid propellant motors ever flown and first designed for reuse
Diameter = ft
Length = ft
Sea Level Thrust: 3,300,000 lb
Weight
With propellant: 1,300,000 lb
Inert: 192,000 lb
Provide ~ 71% of thrust at lift-off and ascent
Propellant mixture by weight
Ammonium perchlorate: 69.6%
Aluminum: 16%
Iron oxide (catalyst): 0.4%
Polymer binder: 12.04%
Epoxy curing agent: 1.96%
Propellant is 11 point star shape in forward motor segments and double truncated cone in aft segments

5. ADDITIONAL EXAMPLES

6. MINUTEMAN SOLID ROCKET
Minuteman first stage motor
Minuteman missile systems, operated by Air Force Combat Command are long-range,
solid-fuel, three-stage intercontinental ballistic missiles capable of carrying single
or multiple nuclear warheads. The program began in 1958 and is one of Boeing's
longest military contracts.

7. PEGASUS SOLID ROCKET

8. Burning Rate Characteristics of RDX Composite

9. GRAIN DESIGNS

10. GRAIN CROSS-SECTIONAL GEOMETRIES

11. SOLID PROPELLANT ROCKETS

12. DIMENSIONS SUMMARY OF CURRENT SRBs

13. MASS SUMMARY OF CURRENT SRBs

14. PERFORMANCE SUMMARY FOR CURRENT SRBs

15. SOLID ROCKET FUEL DATA

16. SOLID ROCKETS AND NOZZLE FLOW
Special issue with solid propellants that use powdered metals as a fuel additive
Adding aluminum to formation of solid propellant increases gas temperature, but incurs performance penalties related to solid particles that are generated
Aluminum burns with oxygen to form Al2O3 particles
Particles are initially liquid and solidify during expansion process
Also tend to agglomerate to become large particles
Large particles do not accelerate as quickly as the gas surrounding them
These particles may constitute as much as 10-25% of total mass
Need to consider this in nozzle design, which must account for two-phase flow
Simplified models exist for analysis of performance:
Results indicate that large particle sizes are a detriment
However, for small particles, there is an optimum amount of Al to add

17. ROCKET FUEL SELECTION GUIDE
Desirable Physical Properties
Low freezing point
High specific gravity (dense propellant)
Stability (with time)
Heat transfer properties
Pumping properties (low vapor pressure, low viscosity)
Small variation in physical characteristics with temperature
Ignition, combustion, and flame properties
Performance of Propellants
Economic Factors
Physical Hazards (Explosion, Fire, Spills)
Health Hazzards
Corrosion

18. HYBRID ROCKETS
Solid Fuel, Liquid Oxidizer Example