High Energy Liquid Propellants for Rockets

Abstract

High energy rocket propellants (such as fluorine, hydrogen, hydrazine, etc.) are of great interest because they result in large increases in vehicle performance over that possible with conventional propellants. This means that for any mission to be accomplished the size and weight of the vehic1e required would be sm aller for the high energy propellants than for conventional propellants. Figure 1 shows the comparative size and weight of two vehic1es for placing a manned satellite in orbit; one uses conventional and the other high energy propellants. The vehic1es are two-stage with a payload of 20,000 pounds. The figure indicates the total propellant volume as a measure of the overall bulk of the vehicle. Also indicated are gross weights. The high energy propellant combination would produce a much smaller bulk and much less weight. Problems associated with very large vehicle structures are reduced by the use of high energy propellants and the consequent reduction in bulk. These differences in bulk and weight for the different propellants become greater as the mission becomes more difficult, that is, as the energy requirements become greater to carry more payload or to go farther, such as to the moon. Some space flight missions may be accomplished only by using high energy propellants because of the tremendous vehicle size that would be required with conventional propellants • High energy propellants can also be used in upper stages with boosters we have today to accomplish missions that would otherwise require the development of boosters of much higher thrust. The reasons for the use of high energy propellants must be very compelling because many problems are encountered due to the unique properties of thepropellants. These problems involve design, materials, handling methods,-1-K. D. Timmerhaus (ed.), Advances in Cryogenic Engineering