Apogee Boost (Kick) Motor

An apogee boost (kick) motor is the propulsion device or function used to raise a satellite from its initial transfer orbit into its final operational orbit by firing near apogee. The maneuver increases orbital energy to raise perigee, typically circularizing the orbit at the desired altitude and often reducing inclination, particularly for geostationary missions.

Historically, the term apogee kick motor referred to a dedicated solid-propellant motor providing a short, high-impulse burn. In modern spacecraft, the same function is frequently performed by liquid-propellant engines or electric propulsion systems integrated into the main thrust subsystem, sometimes over multiple burns. For this reason, the terms apogee kick motor and apogee boost motor are now commonly used interchangeably to describe the apogee-raising function rather than a specific propulsion technology.