Overview of Japan Canada Joint Collaboration Satellites (JC2Sat) GNC Challenges and Design

The Japan Canada Joint Collaboration Satellites – Formation Flight (JC2Sat-FF) project is a joint project between the Canadian Space Agency (CSA) and the Japan Aerospace Exploration Agency (JAXA). This paper presents an overview of JC2Sat mission and discusses unique GNC challenges and solutions with focus on attitude control subsystem (ACS) and relative navigation subsystem (RNS). Preliminary simulations are presented to validate that the design requirements are satisfied by proposed design techniques. Nomenclature Ad = desired geocentric separation latitude prop g sat ( ) a R = satellite gravitational acceleration including only the two-body and J2 perturbation accelerations B = earth magnetic field vector expressed in satellite body coordinates hy e = angular momentum error about the satellite pitch axis h = satellite angular momentum vector expressed in satellite body coordinates h % = satellite angular momentum error vector expressed in satellite body coordinates d h = desired angular momentum vector expressed in satellite body coordinates dw h = desired angular momentum about the satellite pitch axis i = inclination I = satellite moment of inertia matrix expressed in satellite body coordinates 1 2 , , k k k = control gains vo ro k k , = constant gains vr rr k k , = constant gains m = magnetorquer dipole moment vector expressed in the satellite body frame max m = magnetorquer limit vector r = an upper-bound on the covariance of the GPS absolute or relative position error