Propellant Types
Aerotech composite propellant rocket motors are available in three different propellant types, which vary in burn characteristics, flame colour, smoke colour and sound.
All of these solid rocket motors use a base propellant combination which primarily consists of solid Ammonium Perchlorate (AP) oxidiser mixed with a fuel, which also acts as a binding agent. This fuel is a polymer called hydroxyl terminated polybutadene (HTPB). The advantages of this propellant combination, are that it is relatively benign and safe to handle compared with the more volatile state of liquid rocket engine propellants, yet provides an extremely powerful thrust per weight of propellant.
This propellant combination is actually very similar to the propellant combination used in the solid rocket boosters of the space shuttle and solid rocket boosters of other commercial space launcher rockets.
Propellant compounds may be doped with various additives to alter the chemical composition and hence retard or increase the burn rate. Aluminum or magnesium may be employed in smaller motors for smoke generation, or in larger motors for use as additional fuel.
The Aerotech composite propellant solid rocket motors are supplied as pre-cast solid propellant grains. The number of propellant grains depends on the length of the casing used. The propellant grains supplied for a specific casing should never be varied (i.e. you should not leave out grains, or try and modify grains to fit more in a casing, to do so is dangerous, and could result in destruction of a motor).
White Lightning
A brilliant white flame, dense bright white exhaust and a throaty roar are the hall marks of this very popular propellant. It is easy to track and to watch. White Lightning looks and sounds like actual sounding rockets and launch vehicles. Special effects professionals and aerospace companies specify White Lightning propellant to achieve realistic simulation. White Lightning propellant is doped with aluminium and magnesium based alloys, which retard the burn rate, but result in a bright yellow/white flame and white smoke.
The motor powering the rocket in the photograph is a K-700 White Lightning motor. (The rocket is a PML Thunder and Lightning).
Blue Thunder
Produces a bright violet-blue flame with very little smoke. These motors provide a higher level of thrust than the White Lightning or Black Jack motors of the same total impulse, but for a shorter burn time. Blue Thunder is the perfect propellant for the greatest lift-off acceleration, with its high thrust, short burn motors. The Blue Thunder propellant is not doped with additives, and such, is the purest of the three propellants, so to speak. The lack of any dopants, means that the burn rate is not inhibited in any way, and this is why the burn is shorter than for the other propellant formulations.
The motor powering the rocket in the photograph is an I-300 Blue Thunder motor. (The rocket is a PML Quantum Leap).
Black Jack
Provides the high visibility tracking of a dense black exhaust. In addition to a distinctive lift-off roar, Black Jack motors give your motors lower acceleration and longer powered flight than White Lightning or Blue Thunder motors of the same total impulse.
The motor powering the rocket in the photograph is an I-195 Black Jack motor. (The rocket is a PML Tomahawk).
