Gemini liftoff

14x upscale Gemini DC on 1 Aerotech M1939 and 4 Aerotech M1315s

High Power Rocketry is the term used for rockets that use engines with higher impulse than Mid Power or Low Power rockets. These engines vary from "H" up to "O" sizes, though engine sizes up to "R" have been built for extreme payload weight/altitude launches. This the most advanced forms of hobby rocketry, and often employs advanced techniques, such as engine clustering and upscale rocketry