The U.S. National Aeronautics and Space Administration says that the space shuttle holds more than 1 million gallons of propellants at liftoff. The space shuttle uses a combination of oxygen, hydrogen, hydrazine, monomethylhydrazine and nitrogen tetroxide to power the craft, and fuel is needed at liftoff and while in use.
According to NASA, the space shuttle's solid propellant is loaded on a large external tank. This external tank contains over 500,000 gallons of liquid hydrogen and supercooled liquid oxygen, which are blended together to create the fuel that generates the power for the three main rocket engines on the orbiter. These propellants weigh more than 1.6 million pounds.