Design, fabrication and modeling of solid propellant microrocket-application to micropropulsion

The integration of propellant within a silicon micromachined systems enables the realization of a new class of MEMS devices called microscale rocket. These new devices seem to respond to a real need in the field of high energetic microscale actuation. Their main originality is the use of only one solid propellant loaded in a small tank micromachined in a ceramic or silicon substrate, The structure consists of a sandwich of three micromachined silicon substrates: nozzles, igniters and propellant chambers. The thrust force issued from the combustion of the solid propellant ranges from 1 mN to a few mN. Just by geometrical and dimensional considerations, it is possible to adapt the thrust impulse depending on the application requirements. One identified application of microrockets is space with the realization of microscale thrusters for the control of the attitude or/and the station keeping of very small satellite. In a first part of the paper, we present the process of fabrication and the assembling of microthrusters as well as the specific equipment developed to load the solid propellant into microcavities. On a second part, we present briefly the modeling tools developed to predict the (C) 2002 Elsevier Science B.V. All rights reserved. thruster performances.