Comparing hydrogen and hydrocarbon booster fuels

The present evaluation of the consequences of hydrogen and hydrocarbon fuels as the basis of launch vehicle booster rocket-stage performance notes that hydrocarbon fuels lead to lower vehicle dry mass, for low-velocity requirements, while hydrogen fuel furnishes lower dry mass. Vehicles employing both types of fuel attempt to take advantage of the low intercept and slope of hydrocarbon fuel at low velocity, and subsequently, of the slope of the hydrogen curves at higher velocities.