Page 18 - Curriculum Visions Dynamic Book

 The orbiter being attached to the external tank (brown). Note: This picture was taken looking upward inside the vehicle assembly building (VAB). You can see the three main engines and also the two smaller maneuvering engines (with their covers on).
How the Shuttle is designed
The Shuttle is just over 37 m long and has a wing span
of just under 24 m. Fully loaded and waiting for takeoff, together with the external tank and boosters, it weighs 2,000 tonnes! The actual orbiter with its payload may weigh only about 100 tonnes of this total. All the rest is rocket and fuel. The boosters and tank make the final length of the Shuttle at launch just over 56 m.
External tank
The external tank when full weighs 735 tonnes and is the heaviest single part of the Shuttle. It was originally made of aluminum and contains liquid oxygen and liquid hydrogen fuel. By changing to a design made with an aluminum-lithium alloy,
3 tonnes of weight have been saved
(and so more pAyloAd can be carried).
The external tank is connected to the Shuttle for about 8 minutes after takeoff. Then its fuel is used up, and it falls away from a height of 80 km, burning up in the Earth’s atmosphere.
Boosters
The boosters alone weigh 1,170 tonnes when full.
They are the biggest solid fuel motors ever designed. In the tanks are aluminum powder and ammonium perchlorate, which provides the oxygen required to burn the aluminum fuel. To make the fuel burn quickly, there is also an iron oxide cAtAlyst. All of this is held together with a polymer binder and epoxy resin. They provide the extra 29% of the takeoff thrust that cannot be provided by the Shuttle’s own massive engines.
See page 11 of Volume 6: Journey into space for more on the weight of the Space Shuttle.
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