Solid rocket boosters

Modern composite solid propellant is a mechanical mixture of the powder-like chemicals and a binding resin. The propellant used for the Space Shuttle solid rocket boosters (SRBs) is a typical example of such mixture ... 

The solid products form the thick clouds of white powder emitted hy the solid rocket boosters during liftoff (Fig. 15.23). 

The solid rocket boosters of the Space Shuttle are appropriately named for the solid propellant loaded within them. The ignition provided by the reaction of the solid aluminum powder and ammonium perchlorate powder generates a finely divided white powder known as alumina, various gases, and an extensive amount of heat. The dispersal of the white powder in the gases streaming from the boosters creates the billowy white appearance. 

The propellant mixture in each solid rocket booster of the Space Shuttle contains ammonium perchlorate ( the oxidizer, 69.6% by weight), aluminum ( the fuel, 16% by weight), an iron oxide catalyst (0.4% by weight), a polymeric binder that... 

Solid Rocket Boosters. NASA Space Shuttle Reference Manual,... 

The Space Shuttle Solid Rocket Boosters. Student Space Awareness — National Web Team, University of Arizona Chapter of Students for the Exploration and Development of Space, http //seds.lpl.arizona.edu/ssa/docs/Space.Shuttle/srb.shtml... 

The immediate cause was failure of the ring joint seal on the solid rocket booster. Yet, a root-cause analysis revealed a much more complex scenario. According to information published after the investigation, post flight evidence from as far back as early 1984 showed that the joint seals were failing to meet design specifications. 

The U.S. Space Shuttle, for example, has two large solid-rocket boosters for its launch stage. The booster propellant has the following composition ... 

It takes a lot of force to get a space shuttle out of the grip of Earth s gravity. Two solid rocket boosters filled with a solid mixture of ammonium perchlorate and aluminum metal, called the propellant, produce most of that force. The rockets also contain a catalyst made of iron oxide, which speeds up the burning of the propellant. Another material called the binder holds everything together. All together, the propellant, the catalyst, and the binder make up the solid material inside the rocket boosters. 

This reaction is extremely exothermic and heats the inside of the solid rocket booster to about 5,800°F (3,200°C). This extremely high temperature causes the two gases, nitrogen and water vapor, to expand rapidly. This is... 

The reaction happens quickly All the fuel in the solid rocket boosters is used up in about two minutes. When all of the propellant is used up, the boosters separate from the shuttle and fall back to Earth and into the Atlantic Ocean, where a ship picks them up and tows them back to Florida so they can be reused. About 71 % of the upward thrust needed to get the shuttle into orbit comes from the solid rocket boosters. 

The reaction also produces extremely high temperatures—around 6,000°F (3,300°C). The water vapor produces the extra lift the shuttle needs to get out of Earth s orbit. Like the solid rocket boosters, the external tank separates from the shuttle when the fuel is gone. Unlike the boosters, by the time the external tank is released from the shuttle, it is outside of Earth s atmosphere and it burns up as it reenters the atmosphere. 

Solid propellants of essentially all solid rocket boosters are based on a mixture of aluminum (Al, fuel) and ammonium perchlorate (AP, oxidizer). 

Pyrotechnic device—On a spacecraft, an explosive device used for quick release of some mechanism or object. Explosive bolts used to separate rocket stages or the solid rocket boosters used during a space shuttle launch are examples of pyrotechnic devices. 

Using Numbers The space shuttle gains nearly 72% of its lift from its solid rocket boosters (SRBs) during the first two minutes of launch. The two pencil-shaped SRB tanks are attached to both sides of the liquid hydrogen and oxygen fuel tank. Each SRB contains 495 000 kg of an explosive mixture of ammonium perchlorate and aluminum. The unbalanced equation for the reaction is given below. 

Niels Bohr—Atomic Physicist and Humanitarian Solid Rocket Booster Engines... 

Shuttle forces Each solid rocket booster weighs 591 000 kg at liftoff, produces 11.5 million N of force, and operates for about two minutes into the flight. For comparison, a 1000-kg car accelerating from 0 to 26.8 m/s (60 mph) in 7 seconds would require a force of only 3830 N. The tremendous release of chemical energy and expansion of hot gases due to the oxidation-reduction reaction through the engine of the solid rocket booster produces the tremendous thrust needed to get the 2 million-kg shuttle from 0 to almost 700 m/s (1500 mph) in just 132 seconds. 

The space shuttle s solid rocket boosters get their thrust from the reaction of aluminum metal with ammonium perchlorate, NH4CIO4, which generates a lot of gas and heat. The billowy white smoke is due to the formation of very finely divided solid aluminum oxide. One of the reactions that takes place is... 

Hydrogen chloride gas is a noxious byproduct of many industrial chloride processes, and a major product from the combustion of most solid-rocket boosters. A quartz crystal microbalance using trlphenylamine as coating with 10" g/frequency was reported (37). The detector was capable of detecting 10 g of or 2.5 x 10" molecules of HCl. The performance of the detector was demonstrated during the Titan-Centaur launch in 1975. 

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