Satellites from a Combat Aircraft

This work presents the analytical results of a parametric investigation of a launch concept of micro-satellites from a combat aircraft. The concept of air launching of a satellite from a carrier aircraft is not new; however, most designs consider heavy aircraft and launch vehicle to place a mini to a large satellite, typically launched today via ground-based rocket launchers. Documented air launcher designs usually incorporate a lift aided trajectory. It is the authors’ intention to present a method for air launching of a low-cost tactical micro-satellite, on demand, for various missions, using a weight economical vehicle via a Gravity Turn Trajectory. The carrier aircraft will be an F-15 fighter, and the launcher will be a 3-stage vehicle, assembled from a ducted rocket (ramrocket) 1st stage and two solid propellant rocket stages. The option of an air-breathing engine for the first stage results from the high initial speed (as high as Mach 1.6) provided to the launcher by the carrier aircraft. An air-breathing engine provides much higher energetic performance compared to a standard solid rocket motor (higher Isp and lower mass). A ducted rocket was chosen over other ramjet configurations for its higher thrust coefficient. Optimization on initial flight path angle, coasting time, and ducted rocket sizing was done. The solution presents a concept for placing a 50-100 kg micro-satellite in either a circular 250 km low earth orbit (LEO) or a more elliptic LEO. It is demonstrated that a