A gas generator is a device for generating gas. It may take many forms but often refers to a device, similar to a solid rocket or a liquid rocket that burns fuel to produce large volumes of relatively cool gas, instead of maximizing the temperature and specific impulse. The low temperature allows the gas to be put to use more easily in many applications, particularly to drive gas turbines. Gas generators are used to power turbopumps in rocket motors, to deploy airbags, and in other cases where large volumes of gas are needed, and storing it as a pressurized gas is undesirable or impractical.