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astronautix.com BrF5/Hydrazine





Oxidiser: BrF5. Oxidiser Density: 2.48 g/cc. Oxidiser Freezing Point: -63.00 deg C. Oxidiser Boiling Point: 41.00 deg C.

Bromine Pentafluoride was another of the extremely reactive and toxic oxidisers tested in the United States in the late 1950's. As in the other cases, it was found that the handling problems and safety risks outweighed the performance benefits. Commercial bromine pentafluoride is essentially pure BrF5. It is a pale yellow liquid and exhibits the pungent odour which is characteristic of halogen fluoride. Bromine pentafluoride is toxic and stable, and similar to chlorine trifluoride in reactivity and treated as such. It is prepared by the reaction of fluorine and bromine at temperatures above 200 deg C. The price of BrF5 in 1959 was estimated to be $10.00 per kg in hundred-kg lots.


Fuel: Hydrazine. Fuel Density: 1.01 g/cc. Fuel Freezing Point: 2.00 deg C. Fuel Boiling Point: 113.00 deg C.

Hydrazine (N2H4) found early use as a fuel, but it was quickly replaced by UDMH. It is still used as a monopropellant for satellite station-keeping motors. Hydrazine marketed for rocket propellant contains a minimum of 97 per cent N2H4, the other constituent being primarily water. Hydrazine is a clear, water-white, hygroscopic liquid. The solid is white. Hydrazine a toxic, flammable caustic liquid and a strong reducing agent. Its odour is similar that of ammonia, though less strong. It is slightly soluble in ammonia and methyl-amine. It is soluble in water, methanol, ethanol, UDMH, and ethylenediamine. Hydrazine is manufactured by the Raschig process, which involves the oxidation of ammonia to chloramine, either indirectly with aqueous sodium hypochlorite or directly with chlorine, and subsequent reaction of chloramine with excess ammonia. Raw materials include caustic, ammonia, and chlorine; these are high-tonnage, heavy chemicals. The cost of anhydrous hydrazine in drum quantities in 1959 was $ 7.00 per kg. The projected price, based on large-scale commercial production, was expected to be $ 1.00 per kg. Due to environmental regulations, by 1990 NASA was paying $ 17.00 per kg.


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Last update 3 May 2001.
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