Solid rocket booster

Solid rocket boosters (SRBs) are large solid fuel motors used to provide thrust in spacecraft launches from initial launch through the first ascent stage. Many launch vehicles, including the Ariane 5, Atlas V, and the NASA Space Shuttle, use SRBs to give launch vehicles much of the thrust required to escape Earth's gravitational pull. The NASA Space Shuttle used two Space Shuttle SRBs, which were the largest solid fuel motors ever built and the first designed for recovery and reuse. The propellant for each solid rocket motor on the Space Shuttle weighed approximately 500,000 kilograms.