This page no longer updated from 31 October 2001. Latest version can be found at N2O4/Aerozine-50

Oxidiser: N2O4. Oxidiser Density: 1.45 g/cc. Oxidiser Freezing Point: -11.00 deg C. Oxidiser Boiling Point: 21.00 deg C.

Nitrogen tetroxide became the storable liquid propellant of choice from the late 1950's. Nitrogen tetroxide consists principally of the tetroxide in equilibrium with a small amount of nitrogen dioxide (NO2). The purified grade contains less than 0.1 per cent water. Nitrogen tetroxide (N2O4) has a characteristic reddish-brown colour in both liquid and gaseous phases. The solid tetroxide is colorless. N2O4 has an irritating, unpleasant acid-like odour. N2O4 is a very reactive, toxic oxidiser. It is non-flammable with air; however, it will inflame combustible materials. It is not sensitive to mechanical shock, heat, or detonation. Nitrogen dioxide is made by the catalytic oxidation of ammonia; steam is used as a diluent to reduce the combustion temperature. Most of the water is condensed out, and the gases are further cooled; the nitric oxide is oxidised to nitrogen dioxide, and the remainder of the water is removed as nitric acid. The gas is essentially pure nitrogen tetroxide, which is condensed in a brine-cooled liquefier. 1959 production amounted to 60,000 tonnes per year. In carload lots of one-ton cylinders, the price was $ 0.15 per kg. By 1990 NASA was paying $ 6.00 per kg due to environmental regulations.

Fuel: Aerozine-50. Fuel Density: 0.90 g/cc. Fuel Freezing Point: -7.00 deg C. Fuel Boiling Point: 70.00 deg C. Fuel.Comments: A 50-50 mixture of hydrazine and UDMH developed for use in the Titan 2 missile. Copied in one Russian missile but otherwise straight UDMH used more commonly. Higher boiling point than UDMH.
Engines Using N2O4/Aerozine-50

Eng-engineslink Thrust(vac)-kgf Thrust(vac)-kN Isp-sec Isp (sea level)-sec Designed for Status
SE-9-3 11   295      
SE-9-5 20   300      
RM-100T 45   296      
AJ10-131 1,000          
RS-18 1,587   310      
Astris 2,380 23.30 310 260 Upper Stages Out of Production
AJ10-138 3,628 35.60 311   Upper Stages Out of Production
TR-201 4,275 41.90 301   Upper Stages Out of Production
AJ10-118K 4,425 43.40 321 120 Upper Stages In Production
SE-10 4,760   305      
LE-3 5,440   285      
AJ10-137 9,900 97.50 312   Upper Stages Out of Production
RD-280 11,992 117.60 350   Upper Stages Developed 1963-65
Ares 45,000 440.00 370   First Stages Development 1968.
LR-91-5 45,357 444.80 315   Upper Stages Out of Production
LR-91-7 45,359 444.80 316 160 Upper Stages Out of Production
LR91-9 45,745   316   Upper Stages Out of Production
LR-91-11 46,857 467.00 316 160 Upper Stages In Production
LR-87-7 110,753 1,086.10 296 258 First Stages In Production
LR-87-5 111,844 1,096.80 297 259 First Stages Out of Production
LR-87-11 124,280 1,218.80 302 250 First Stages In Production
LR-87+ 166,666 1,634.40 293 258 First Stages Study 1965

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Last update 3 May 2001.
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© Mark Wade, 2001 .