Want to stay on top of all the space news? Follow @universetoday on TwitterThe solid fuel rocket has one of the simplest designs in rocketry. The solid rocket fuel that powers this type is the majority of the rocket’s design. However the type of solid propellant powering it can vary depending on the type of rocket being used. Those used for simple fireworks use the traditional nitrogen single base compounds. For rockets such as the booster rockets used to launch space craft have the propellant is more complex, a category of solid propellants called compound propellants.
The first solid rocket fuel was gunpowder and was developed by the Chinese sometime in the first millennium AD. Chinese gunpowder for military rockets was very inefficient and was only used for broad bombardments. The real revolution of design came in the 19th century with the work of Sir William Congreve. Drawing inspiration from the rockets used by Irish nationals during the Emmet Rebellion he developed the first iron casing solid rocket fuel missile for military application. There is further evidence that the British military also took cues from the rockets used by Indian kingdoms at that time.
Over the decades solid fuels were developed to produce more thrust and have more control. The main innovation lay in the composition of the fuel. The fuels not only used traditional gunpowder but went to used different metal oxides. These increased the power of the rocket and the distance it could travel. They also were considered more attractive than liquid fuel rockets which debuted in earnest with the introduction of the German V-2 rocket during WWII. The fueling and storage of liquid fuel was more difficult and dangerous so solid fuel rockets were considered a more attractive alternative since they are easy to store and fuel.
Solid Fuel rockets became more effective with the invention of castable solid fuel propellants. The first were asphalt with a binding agent and perchlorates as the oxidizer. This changed to metal oxides mixed with perchlorates to make a rubbery substance. These new solid rocket fuels not only delivered more punch but also left few traces in the exhaust making solid fuel missiles more attractive. With the success of this research during the 50′s solid fuel rockets were adapted for space flight and became the booster rocket of choice for sending payloads into space. Even now in modern times due their consistent reliability and relatively cheap costs they continue to be used by space programs worldwide.
We’ve recorded an episode of Astronomy Cast all about the space shuttle. Listen here, Episode 127: The US Space Shuttle.