Small hybrid thruster development for small satellite attitude control system

Through this work we show the development of small hybrid rocket thrusters intended for attitude control systems of small satellites and space-crafts. These thrusters have the advantage of being controllable and having higher specific impulse than the traditional solid fuel thrusters or hydrazine based thrusters. An internal ballistic model of the small hybrid thrusters is shown together with numerical results for the thrust-curves and other relevant parameters. The internal ballistic model is shown to be influenced by the regression speed and the need for higher regression speed fuel-oxidizer pairs is, hence, shown. In the present study we also show how to couple the hybrid combustion process with the unsteady flow. Moderately high specific impulses can be obtained by using polypropylene as fuel and NO2 as oxidizer. Detailed discussion is done on the construction of the thrusters as well as the engineering solutions for the combustion chamber, injector and nozzle. Several experimental thrust-curves are shown together with the estimation of total impulse and specific impulse.