Nanosatellite orbit control using MEMS cold gas thrusters

Abstract

We introduce nanosatellite orbit control using a novel miniaturized cold gas propulsion module based on microelectromechanical systems (MEMS) technology. Firstly, the design and characteristics of the propulsion module suitable for CubeSat class nanosatellites are described. Secondly, mission analyses for in-orbit validation of the propulsion module on a 2-unit CubeSat in 300 km low Earth orbit are presented. The MEMS cold gas propulsion module with 10 cm × 10 cm × 3 cm dimensions and 220 g mass is specifically designed for use in CubeSats. In baseline configuration with a tank for 60 g of butane under 2 to 5 bar pressure, it can provide up to 15 m/s delta-V capability for a 2.66 kg satellite. The module includes four individually controllable thrusters with proportional thrust regulation and closed loop control; maximum thrust is 1 mN per thruster with 5 1N thrust resolution. The fully operational satellite with active orbital control is capable of accommodating a 0.64 kg and 10 cm × 10 cm × 7 cm additional payload. The analysed mission scenarios have potential for different Earth observation applications. Natural deorbiting, controlled orbit lowering, controlled orbit raising, and orbit keeping at 300 km altitude are simulated. Simulations indicate that the natural orbit lifetime can be extended from 63 days to 193 days with the baseline propulsion module and satellite altitude can be increased to 348 km or lowered to 257 km. Orbit keeping at 300 km is possible for up to 76 days; proportional thrust control could provide a further increase to 204 days.