Pulsed rocket motor

A pulsed rocket motor is typically defined as a multiple-pulse solid-fuel rocket motor. This design overcomes the limitation of solid propellant motors being unable to be easily shut down and reignited. The pulse rocket motor allows the motor to be burned in segments (or pulses) that burn until completion of that segment. The next segment can be ignited on command by either an onboard algorithm or in a pre-planned sequence. All of the segments are contained in a single rocket motor case, as opposed to staged rocket motors.

The pulsed rocket motor is made by pouring each segment of propellant separately. Between each segment is a barrier that prevents the other segments from burning until ignited. At ignition of a second pulse, the burning of the propellant generally destroys the barrier.

The benefit of the pulsed rocket motor is that, by the on-command ignition of the subsequent pulses, near-optimal energy management of the propellant burn can be accomplished. Each pulse can have a different thrust level and burn time, and achieve a different specific impulse depending on the type of propellant used, its burn rate, its grain design, and the current nozzle throat diameter.