What is the difference between black powder and composite propellant?
Black powder is a pressed mixture of Potassium Nitrate, Sulfur and charcoal. This propellant has been used for hundreds of years but has relatively low performance. In contrast, composite propellant is usually composed of a mixture of Ammonium Perchlorate, synthetic rubber and a metal fuel like Aluminum. Its performance can be up to three times that of black powder by weight, and because of this it is commonly used in all sorts of military rockets and the Space Shuttle solid rocket boosters (SRBs). It has other important advantages, too.
