Abstract
Small-scale reusable sounding rocket system is under development to provide means of stratosphere observation and three-minutes microgravity experiment. The propulsion system is a hybrid type that uses solid fuel (plastics) and liquid oxygen as propellants and free from explosives, resulting in the dramatically reduced launch cost. To enhance the burning rate of the solid fuel and to augment the thrust, the rocket has employed a new fuel grain design. This new design, named CAMUI as an abbreviation of "Cascaded Multistage Impinging-jet", allows mixing and combustion to occur around stagnation points on fuel surfaces. Successful launch experiments using a 50-kgf CAMUI engine have proved the feasibility of the basic idea of the system. Finally, possible configurations of the stratosphere observation vehicle and the microgravity test vehicle are presented.
