Arocket (from Italian: rocchetto, lit. 'bobbin/spool') is a vehicle that uses jet propulsiontoaccelerate without using any surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely from propellant carried within the vehicle; therefore a rocket can fly in the vacuum of space. Rockets work more efficiently in a vacuum and incur a loss of thrust due to the opposing pressure of the atmosphere.
Chemical rockets are the most common type of high power rocket, typically creating a high speed exhaust by the combustionoffuel with an oxidizer. The stored propellant can be a simple pressurized gas or a single liquid fuel that disassociates in the presence of a catalyst (monopropellant), two liquids that spontaneously react on contact (hypergolic propellants), two liquids that must be ignited to react (like kerosene (RP1) and liquid oxygen, used in most liquid-propellant rockets), a solid combination of fuel with oxidizer (solid fuel), or solid fuel with liquid or gaseous oxidizer (hybrid propellant system). Chemical rockets store a large amount of energy in an easily released form, and can be very dangerous. However, careful design, testing, construction and use minimizes risks. (Full article...)
The first (STS-1) of four orbital test flights occurred in 1981, leading to operational flights (STS-5) beginning in 1982. Five complete Space Shuttle orbiter vehicles were built and flown on a total of 135 missions from 1981 to 2011. They launched from the Kennedy Space Center (KSC) in Florida. Operational missions launched numerous satellites, interplanetary probes, and the Hubble Space Telescope (HST), conducted science experiments in orbit, participated in the Shuttle-Mir program with Russia, and participated in the construction and servicing of the International Space Station (ISS). The Space Shuttle fleet's total mission time was 1,323 days. (Full article...)
Image 9The 'convocation of eagles chasing hare' rocket launcher from the Wubei Zhi (17th century). A double-ended rocket pod that carries 30 small poisoned rockets on each end for a total of 60 rockets. It carries a sling for transport. (from History of rockets)
Image 20A "long serpent enemy breaking" fire arrow launcher as depicted in the Wubei Zhi (17th century). It carries 32 medium small poisoned rockets and comes with a sling to carry on the back. (from History of rockets)
Image 21Robert Goddard and the first liquid-fueled rocket. (from History of rockets)
Image 22Rocket thrust is caused by pressures acting in the combustion chamber and nozzle. From Newton's third law, equal and opposite pressures act on the exhaust, and this accelerates it to high speeds. (from Rocket engine)
Image 23Robert Anderson suggests using metal for rocket casing (from History of rockets)
Image 24Rocket vehicle mechanical efficiency as a function of vehicle instantaneous speed divided by effective exhaust speed. These percentages need to be multiplied by internal engine efficiency to get overall efficiency. (from Rocket engine)
Image 25An illustration of fire arrow launchers as depicted in the Wubei Zhi (17th century). The launcher is constructed using basketry. (from History of rockets)