The Proton launcher

The capabilities, design features and missions for the Soviet Proton booster are described. The Proton, outfitted with six strap-on boosters, launched the Vega 1 and 2 Venus/Halley dual mission spacecraft. RD-253 engines burn N2O4 and UDMH fuels, possibly through a preburner before the combustion chamber. A vacuum thrust of 450,000 lb is projected for the engine. Analyses are presented to set the launch weight at 1,600,000 lb, implying that the vehicle is based on an ICBM design. It is suggested that the Proton has sufficiently high noise and vibration levels to prohibit it from being man-rated.