Space shuttle fuels/propellants

One spectacular example of the oxidizing ability of perchlorates is their use in the booster rockets of space shuttles. The solid propellant consists of aluminum powder (the fuel), ammonium perchlorate (the oxidizing agent as well as a fuel), and iron(III) oxide (the catalyst). These reactants are mixed into a liquid polymer, which sets to a solid inside the rocket shell. A variety of products can form when the mixture is ignited. One of the reactions is... 

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... 

The "newest" oxidizer to appear in pyrotechnics, ammonium perchlorate has found considerable use in modern solid-fuel rocket propellants and in the fireworks industry. The space shuttle alone uses approximately two million pounds of solid fuel per launch the mixture is 70% ammonium perchlorate, 16% aluminum metal, and 14% organic polymer. 

Perchlorates are the most oxidized of the salts of the chlorooxyacids. Although perchlorates are not particularly toxic, ammonium perchlorate (NH4C104) should be mentioned because it is a powerful oxidizer and reactive chemical produced in large quantities as a fuel oxidizer in solid rocket fuels. Each of the U.S. space shuttle booster rockets contains about 350,000 kg of ammonium perchlorate in its propellant mixture. By 1988, U.S. consumption of ammonium perchlorate for rocket fuel uses was of the order of 24 million kg/year. In May 1988, a series of massive explosions in Henderson, Nevada, demolished one of only two plants producing ammonium perchlorate for the U.S. space shuttle, MX missile, and other applications, so that supplies were severely curtailed. The plant has since been rebuilt. 

Hydrazine has been used as fuel for many rockets and spacecraft, including the space shuttle. Hydrazine is used to treat boiler water to reduce corrosion, to reduce other chemicals, and to bring about or speed up chemical reactions. It is also used as a medicine and to make other medicines, farm chemicals, and plastic foams. 1,1-Dimethylhydrazine has been used as a rocket propellant and to make other chemicals. Other uses are also possible. 1,2-Dimethylhydrazine has no commercial uses but is used in labs to study colon cancer in experimental animals. 

Space Shuttle PropeUants At liftojf, the arbiter and an external fuel tank carry 3,164,445 L of the liquid propellants hydrogen, oxygen, hydrazine, monomethylhydrazine, and dinitrogen tetroxide. Their total mass is 727,233 kg. Data for the propellants carried at liftoff are given in Table 10.6. 

Aerospace Industry AppUcations. NASA s space program utilizes cryogenic liquids to propel rockets. Rockets carry liquid hydrogen for fuel and liquid oxygen for combustion. Cryogenic hydrogen fuel is what enables NASA s workhorse space shuttle to get into orbit. Another application is using liquid helium to cool the infrared telescopes on rockets. 

In the space shuttle s main engines, hydrogen molecules, H2 (white), and oxygen molecules, O2 (red), which are stored In the central fuel tank, react violently to form water molecules, H2O. The reaction emits the energy that helps propel the shuttle into space. 

The newest oxidizer to appear in significant use in pyrotechnics, anunonium perchlorate (AP), has found considerable use in modem solid-fuel rocket propellants and in the firewoiks industry. The Space Shuttle alone uses approximately 2 million pounds of solid fuel per launch the mixture is 70% ammonium perchlorate, 16% almninum metal, and 14% organic polymer/epoxy, with a trace of iron oxide catalyst that can be varied to modify the bum rate. The aluminum powder is a surprising ingredient to find in a propellant, since it generates solid rather than gaseous reaction products, but its substantial heat output as a fuel and its excellent thermal conductivity both contribute to an enhancement of the bum rate of this propellant formulation. 

Solid propellants are also used as rocket fuels. The mixture used in the booster rockets of the space shuttles (Figure 6.17) is a fuel containing aluminum metal powder. An oxidizer of ammonium perchlorate, NH4CIO4, is mixed with the fuel. 

Perchlorate ion is one of the components in the solid fuel that propels the booster rockets of the Space Shuttle. 

To understand the technical root cause. Figure 7.8 shows the shuttle system, including the two SRBs, external fuel tank, and shuttle main orbiter vehicle. The SRBs con-tribnte 80% of thrnst at liftoff. They bum for two minutes when, with fuel exhausted, they separate from the orbiter 24 miles downrange and drop by parachute to the sea. The SRBs are made up of a nose forward section, a shroud aft section that covers the nozzle, and a solid-propellant rocket motor (SRM). The SRM consists of four sections, each of which were cast with propellant in the Morton Thiokol factory in Utah and shipped to the Kennedy Space Flight Center in Florida for assembly. 

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