LOX/Kerosene
Propellant Formulation: LOX/Kerosene. Isp: 353.00 vac. Isp: 300.00 sl. Optimum
Oxidizer to Fuel Ratio: 2.56. Density: 1.02 g/cc. Temperature of Combustion:
3,670.00 deg K. Ratio of Specific Heats: 1.24. Characteristic velocity c: 1,805
m/s. Isp Shifting: 301. Isp Frozen: 286. Pp Isp Shifting: 307. Mol: 23.30 M.
Oxidizer: LOX. Oxidizer Density: 1.14 g/cc. Oxidizer Freezing Point:
-219.00 deg C. Oxidizer Boiling Point: -183.00 deg C.
Liquid oxygen was the earliest, cheapest, safest, and eventually the preferred
oxidizer for large space launchers. Its main drawback is that it is moderately
cryogenic, and therefore not suitable for military uses where storage of the
fuelled missile and quick launch are required. Liquid oxygen, as normally
supplied, is of 99.5 percent purity and is covered in the United States by
Military Specification MIL-P-25508. High purity liquid oxygen has a light blue
color and is transparent. It has no characteristic odor. Liquid oxygen does not
burn, but will support combustion vigorously. The liquid is stable; however,
mixtures of fuel and liquid oxygen are shock-sensitive. Gaseous oxygen can form
mixtures with fuel vapors that can be exploded by static electricity, electric
spark, or flame. Liquid oxygen is obtained from air by fractional distillation.
The 1959 United. States production of high-purity oxygen was estimated at nearly
2 million tons. The cost of liquid oxygen, at that time, ex-works, was $ 0.04
per kg. By the 1980's NASA was paying $ 0.08 per kg.
Fuel: Kerosene. Fuel Density: 0.81 g/cc. Fuel Freezing Point: -73.00 deg
C. Fuel Boiling Point: 147.00 deg C.
In January 1953 Rocketdyne commenced the REAP program to develop a number of
improvements to the engines being developed for the Navaho and Atlas missiles.
Among these was development of a special grade of kerosene suitable for rocket
engines. Prior to that any number of rocket propellants derived from petroleum
had been used. Goddard had begun with gasoline, and there were experimental
engines powered by kerosene, diesel oil, paint thinner, or jet fuel kerosene
JP-4 or JP-5. The wide variance in physical properties among fuels of the same
class led to the identification of narrow-range petroleum fractions, embodied in
1954 in the standard US kerosene rocket fuel RP-1, covered by Military
Specification MIL-R-25576. In Russia, similar specifications were developed for
kerosene under the specifications T-1 and RG-1. The Russians also developed a
compound of unknown formulation in the 1980's known as 'Sintin', or synthetic
kerosene. Rocket propellant RP-1 is a straight-run kerosene fraction, which is
subjected to further treatment, i.e., acid washing, sulphur dioxide extraction.
Thus, unsaturated substances which polymerize in storage are removed, as are
sulphur-containing hydrocarbons. Furthermore, in order to meet specification
requirements of density, heat of combustion, and aromatic content, the kerosene
must be obtained from crudes with a high naphthene content. RP-1 is an excellent
solvent for many organic materials. The flash point is above 43 deg C. Above
that temperature RP-1 will form explosive mixtures with air. The temperature
range for explosive mixtures (rich limit) is 79 to 85 deg C. RP-1 is not so
toxic as the JP series of fuels because of its lower aromatic content. In the
United States, suitable kerosene fractions in 1960 were limited almost
exclusively to the West Coast. The estimated 1956 United States production was
7700 tons, and the price was $0.05 per kg. By the 1980's it was typically $ 0.20
per kg. Russian formulations have typical densities of 0.82 to 0.85 g/cc, and
even higher densities were achieved in the N1 and Soyuz 11A511U rockets by
superchilling the fuel prior to loading.
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