Mass-Ejecting Reaction Wheel for CubeSat Small Orbit Corrections

Abstract

CubeSats usually carry no propulsion system because of difficulties in scaling down existing propulsion technologies to meet the stringent size, volume, and power limits. The most challenging case in this context is the one-unit CubeSat: the use of which has been rapidly growing. To increase CubeSat functionality by allowing small orbit corrections, particularly due to orbit injection errors, this paper develops a new propulsion method relying on an ejection of masses from a reaction wheel. Using the reaction wheel’s kinetic energy, propellant masses are released from the wheel’s outer circumference using an impulsive application of an electric current. This paper models the dynamics of the satellite, the modified reaction wheel, and the ejected masses; evaluates the pros and cons of the proposed method; and provides a methodology for constructing a model of a mass-ejecting reaction wheel designed according to given specifications of a desired velocity change and satellite attitude stability. The system is useful for small orbit corrections, which can be used (for example) for CubeSat formation establishment after orbital injection.