Solid-Fuel Rockets

Solid-fuel rockets are the simplest and oldest type of rockets. Aircraft have been armed with solid-fuel rockets since World War I, when they were used to attack airships and observation bal­loons. Rockets fired from one aircraft at another aircraft are called air-to-air rockets. The airships and balloons were filled with hydrogen, which burned if a flaming rocket flew into it. The problem was that the planes of the day also were made of flammable materials, so firing rockets from them was dangerous. The rockets also were inaccurate and rarely hit their targets.

Small air-to-air rockets were used again in World War II. They enabled fighters to attack bombers without com­ing within range of the bombers’ guns. These small rockets were unguided-they were aimed simply by pointing the

О The Space Shuttle has two solid rocket boost­ers (SRB) that are strapped to its external fuel tank. The SRB are discarded about 2 minutes after liftoff, and they fall back to Earth to be retrieved and reused.

ROBERT H. GODDARD (1882-1945)

 

Solid-Fuel Rockets

Solid-Fuel RocketsRobert Hutchings Goddard was an American scientist and inventor who developed the modern liquid-fuel rocket. He received patents for a liquid-fuel rocket and a two – stage rocket in 1914. In 1919, Goddard wrote a paper called "A Method of Reaching Extreme Altitudes," in which he talked about sending a rocket to the Moon. He was ridiculed at the time for even suggesting such a crazy idea. In 1926, Goddard suc­ceeded in building and launching the first liquid-fuel rocket. Powered by gasoline and liquid oxygen, the small rocket rose to a height of 41 feet (12 meters). Goddard went on to build bigger and more powerful rockets. Some of them climbed higher than

9,0 feet (2,740 meters) and went faster than the speed of sound. Goddard was the first person to steer a rocket by using vanes in the rocket exhaust, and he designed the first gyroscopic systems for guiding rock­ets. NASA’s Goddard Space Flight Center is named in his honor.

Solid-Fuel RocketsC Robert Goddard displays his liquid oxygen-gasoline rocket before its successful launch in 1926.

whole plane. In the 1950s, air-to-air rockets were replaced by guided missiles.

Solid-fuel rockets are used to help launch spacecraft. Space launch rockets are liquid-fuel rockets, but they can be made more powerful by strapping solid- fuel rockets around them. The solid rock­ets provide extra power for liftoff. Extra rockets used like this are called boosters. The Space Shuttle is launched with the
help of two solid rocket boosters (SRB). They burn powdered aluminum fuel with ammonium perchlorate oxidizer. The propellants are mixed as liquids and then set hard in a mold. A hole runs through the center of the rocket. When the propellants are ignited, they burn from the inside out. Once solid-fuel rockets have been lit, they cannot be turned off.