Ejection charge (commonly Black Powder),[1] also called expelling charge, is a pyrotechnic composition, a type of a pyrotechnic gas generator designed to produce a small short-term amount of thrust to burst open a container and eject its content.
In model rocketry, ejection charges are used to deploy a recovery system (usually parachute or streamer).
The ejection charge is ignited through a layer of delay composition, to fire shortly after the main engine burns out.
Ejection charges can be also triggered by a timer or an altimeter.
In cluster bombs, ejection charges are used to disperse the submunitions.