Qassam Rocket - Rocket Design and Cost

Rocket Design and Cost

The aim of the Qassam rocket design appears to be ease and speed of manufacture, using common tools and components. To this end, the rockets are propelled by a solid mixture of sugar and potassium nitrate, a widely available fertilizer. The warhead is filled with smuggled or scavenged TNT and urea nitrate, another common fertilizer.

The rocket consists of a steel cylinder, containing a rectangular block of the propellant. A steel plate which forms and supports the nozzles is then spot-welded to the base of the cylinder. The warhead consists of a simple metal shell surrounding the explosives, and is triggered by a fuse constructed using a simple firearm cartridge, a spring and a nail.

While early designs used a single nozzle which screwed into the base, recent rockets use a seven-nozzle design, with the nozzles drilled directly into the rocket baseplate. This change both increases the tolerance of the rocket to small nozzle design defects, and eases manufacture by allowing the use of a drill rather than a lathe during manufacture due to the smaller nozzle size. However due to the cone shape of each of the 7 nozzles, each nozzle's inside must be made with a lathe, or else the interior of the nozzle would be cylindrical rather than conical (see rocket engine nozzle). Unlike many other rockets, the nozzles are not canted, which means the rocket does not spin about its longitudinal axis during flight. While this results in a significant decrease in accuracy, it greatly simplifies rocket manufacture and the launch systems required.