For takeoff, the space shuttle had two of these boosters, each of which weighed 650 tons and, amazingly, used metal as fuel: they burned aluminum. Once the fuel was spent, the boosters were jettisoned by the shuttle at an altitude of over 25 miles and eventually deployed parachutes so they would splash down into the Atlantic Ocean. Reuse was the name of the shuttle game, so NASA would send boats out to collect the boosters and take them off to be reconditioned and refueled. As they slammed into the ocean, the boosters were basically empty tubes.
