Laser-Ignited Micromotor Using Multiple Stacked Solid Propellant Pellets

This study proposes the laser-ignited micromotor (LIMO), which is a new propulsion system for CubeSats to overcome the problems associated with conventional chemical propellants. The solid propellant pellets are stacked and stored in the micromotor. This concept makes it possible to design the total impulse of the micromotor in a flexible manner at a low cost and in a short time, depending on microsatellite missions. In addition, a laser-ignition system is integrated with the micromotor to address the problems of ignition delay and the difficulty in cutting the high-current feed lines of the ignition system. Firing tests are conducted in a vacuum chamber using four types of micromotors with different characteristics; that is, each type has a different number of solid propellant pellets and a different ignition system. Total impulses of 184 and 229 N . s are achieved by the two types of LIMOs with 98 and 140 stored pellets, respectively, with a burning rate of 30.4 mm/s. Ignition delay is improved from 0.37 to 0.04 s by using the laser-ignition system. In addition, an engineering model of the LIMO is designed.