How do solid fuel rockets work

Any system that throws mass would do. If you could figure out a way to accelerate baseballs to extremely high speeds, you would have a viable rocket engine. The only problem with such an approach would be the baseball "exhaust" high-speed baseballs at that left streaming through space.

This small problem causes rocket engine designers to favor gases for the exhaust product. Many rocket engines are very small. For example, attitude thrusters on satellites don't need to produce much thrust. One common engine design found on satellites uses no "fuel" at all -- pressurized nitrogen thrusters simply blow nitrogen gas from a tank through a nozzle.

Thrusters like these kept Skylab in orbit, and are also used on the shuttle's manned maneuvering system. New engine designs are trying to find ways to accelerate ions or atomic particles to extremely high speeds to create thrust more efficiently. See this page for additional discussion of plasma and ion engines. Sign up for our Newsletter! Mobile Newsletter banner close. Mobile Newsletter chat close. Mobile Newsletter chat dots. Mobile Newsletter chat avatar.

Mobile Newsletter chat subscribe. Space Transportation Systems. How Rocket Engines Work. HowStuffWorks See more rocket pictures. The vacuum of space Heat management problems The difficulty of re-entry Orbital mechanics Micrometeorites and space debris Cosmic and solar radiation The logistics of having restroom facilities in a weightless environment.

If you have ever shot a shotgun , especially a big gauge shotgun, then you know that it has a lot of "kick. That kick is a reaction. A shotgun is shooting about an ounce of metal in one direction at about miles per hour, and your shoulder gets hit with the reaction.

If you were wearing roller skates or standing on a skateboard when you shot the gun, then the gun would be acting like a rocket engine and you would react by rolling in the opposite direction. If you have ever seen a big fire hose spraying water, you may have noticed that it takes a lot of strength to hold the hose sometimes you will see two or three firefighters holding the hose.

The hose is acting like a rocket engine. The hose is throwing water in one direction, and the firefighters are using their strength and weight to counteract the reaction. If they were to let go of the hose, it would thrash around with tremendous force.

If the firefighters were all standing on skateboards, the hose would propel them backward at great speed! When you blow up a balloon and let it go so that it flies all over the room before running out of air, you have created a rocket engine.

In this case, what is being thrown is the air molecules inside the balloon. Many people believe that air molecules don't weigh anything, but they do see the page on helium to get a better picture of the weight of air. When you throw them out the nozzle of a balloon, the rest of the balloon reacts in the opposite direction. More on Rocket Engines. Photo courtesy NASA. Thrust " ". Solid-fuel Rockets: Fuel Mixture " ". Solid-fuel Rockets: Channel Configuration " ". The propellant mixture in each SRB motor consists of an ammonium perchlorate oxidizer, The combustion produces great amounts of exhaust gas at high temperature and pressure.

The amount of exhaust gas that is produced depends on the area of the flame front and engine designers use a variety of hole shapes to control the change in thrust for a particular engine. The hot exhaust gas is passed through a nozzle which accelerates the flow. Thrust is then produced according to Newton's third law of motion. The amount of thrust produced by the rocket depends on the design of the nozzle. The smallest cross-sectional area of the nozzle is called the throat of the nozzle.

The oxidizer and fuel are mixed and ignited inside the combustion chamber and thrust is created. Unfortunately, the last point makes liquid propellant rockets intricate and complex.

A real modern liquid bipropellant engine has thousands of piping connections carrying various cooling, fueling, or lubricating fluids. Also, the various sub-parts such as the turbopump or regulator consist of separate vertigo of pipes, wires, control valves, temperature gauges, and support struts. Given the many parts, the chance of one integral function failing is large. As noted before, liquid oxygen is the most commonly used oxidizer, but it too has its drawbacks.

To achieve the liquid state of this element, a temperature of degrees Celsius must be obtained--conditions under which oxygen readily evaporates, losing a large sum of oxidizer just while loading. The latter point is a measurement similar to density and as it rises higher so to does the propellant's performance.

But, nitric acid is hazardous in handling mixture with water produces a strong acid and produces harmful by-products in combustion with fuel, thus its use is limited. Developed in the second century BC, by the ancient Chinese, fireworks are the oldest form of rockets and the most simplistic.

Originally fireworks had religious purposes but were later adapted for military use during the middle ages in the form of "flaming arrows. During the tenth and thirteenth centuries, the Mongols and the Arabs brought the major component of these early rockets to the West: gunpowder. Although the cannon, and gun became the major developments from the eastern introduction of gunpowder, rockets also resulted.

These rockets were essentially enlarged fireworks which propelled, further than the longbow or cannon, packages of explosive gunpowder. During the late eighteenth century imperialistic wars, Colonel Congreve developed his famed rockets, which trave range distances of four miles. The "rockets' red glare" American Anthem records the usage of rocket warfare, in its early form of military strategy, during the inspirational battle of Fort McHenry.

A fuse cotton twine coated with gunpowder is lit by a match or by a "punk" a wooden stick with a coal-like red-glowing tip. This fuse burns rapidly into the core of the rocket where it ignites the gunpowder walls of the interior core.

As mentioned before one of the chemicals in gunpowder is potassium nitrate, the most important ingredient. The molecular structure of this chemical, KNO3, contains three atoms of oxygen O3 , one atom of nitrogen N , and one atom of potassium K. A solid fuel rocket has its fuel and oxidant mixed together as fine powders and then pressed in to a solid 'cake'. Once it has been lit it will carry on burning until it is used up.

In a black powder rocket the fuel is carbon and the oxidant, potassium nitrate. Sulphur acts as a secondary fuel and also catalyses the reaction.