Rocket Propulsion Elements, 9th Edition

CHAPTER 7LIQUID PROPELLANTS

The classification of liquid propellants was first introduced in Section 6.1. In this chapter, we discuss properties, performance, hazards, and other characteristics of commonly used propellants that are stored as liquids (and a few as gases). These characteristics influence engine and vehicle design, test facilities, and propellant storage and handling. At the present time, we ordinarily use three liquid bipropellant combinations: (1) the cryogenic oxygen–hydrogen propellant system, used in upper stages and sometimes booster stages of space launch vehicles, giving the highest specific impulse nontoxic propellant combination and one that is best for high vehicle velocity missions; (2) the liquid oxygen–hydrocarbon propellant combination, used for booster stages (and a few second stages) of space launch vehicles —having a higher average density allows more compact booster stages with less inert mass when compared to the previous combination (historically, it was developed first and was originally used with ballistic missiles); (3) not a single bipropellant combination but several ambient temperature storable propellant combinations used in large rocket engines for first and second stages of ballistic missiles and in almost all bipropellant low‐thrust, auxiliary or reaction control rocket engines (this term is defined below); these allow for long‐term storage and almost instant readiness (starting without the delays and the precautions that come with ...