Nuclear thermal engines use the heat of a nuclear reactor to heat a propellant. Although early Russian designs used ammonia or alcohol as propellant, the ideal working fluid is the liquid form of the lightest element, hydrogen. Nuclear engines would have twice the performance of conventional chemical rocket engines. Although successfully tested in both Russia and America, they have never been flown due primarily to environmental and safety concerns.
Ammonia (NH3) is a colourless gas and liquid with a strong irritating characteristic odour. It is a relatively high-boiling gas with a vapour pressure of 8.7 bar at 20 deg C. Ammonia. is toxic, and will dissolve easily in water. It will form flammable and explosive mixtures with air. Although ammonia itself is toxic, the exhaust gases from the combustion of ammonia and oxygen are not. Ammonia is produced by a Haber-Bosch process, in which the elements, nitrogen and hydrogen, are united at a temperature of 500 to 600 deg C and a. pressure of approximately 200 bar in the presence of a promoted iron catalyst. It is estimated that 4 million tonnes of anhydrous synthetic ammonia were produced in 1959 in the United States, at which time the price of tank-car quantities of refrigeration-grade anhydrous ammonia was $ 80 per tonne.
|Eng-engineslink||Thrust(vac)-kgf||Thrust(vac)-kN||Isp-sec||Isp (sea level)-sec||Designed for||Status||YaRD OKB-456||140,000||1,373.00||470||430||First Stages||Developed 1958-1960|