|"Space Shuttle." Encyclopedia Britannica CD 97.||"main engines fire together, producing 7,000,000 lbs (31,000,000 N) of thrust"||3.1 × 107 N|
|McAleer, Neil. The Omni Space Almanac. World Almanac, 208.||"five engines deliver a total of 6,425,000 lbs of thrust"||2.9 × 107 N|
|Gatland, Kenneth. Space Technology. Orion, 226.||"a combined thrust of nearly 6.5 million lb (2.95 million kg)"||2.9 × 107 N|
|Mullane, R. Mike. Do Your Ears Pop in Space? New York: Wiley, 25.||"To get this off the ground, the shuttles liquid and solid fueled engines generate about 7.5 million pounds of thrust."||3.3 × 107 N|
On April 12, 1981, the space program entered a new era with the launch of the Space Shuttle or Space Transportation System (STS). It was the first manned spacecraft designed for reuse.
The Shuttle is composed of a winged orbiter, drop tank, and two solid rockets. The winged orbiter is what contains the crew, equipment, cargo, Space Lab, computers and three main engines. It is basically the only thing which returns to earth from outer space. The drop tank contains a majority of the fuel which drops off and disintegrates in the earth's atmosphere after the fuel has been used up. The 2 solid rockets are boosters that help in lifting the shuttle through its first stage of flight. After being used they are dropped into the ocean where are retrieved, refurbished and reused. They can be reused up to 20 times.
The engines of the shuttle are internal combustion engines. The rocket develops thrust by rearward ejection of mass at a very high velocity. This is when the gas is released and burned. When all the engines are fired up, they create approximately 30 million newtons of thrust which launches the space shuttle upwards.
Colin Lew -- 1998