This paper presents the development of an attitude determination and control subsystem (ADCS) for a technology demonstration mission launched by the University of Washington. HuskySat-1 is a 3U CubeSat equipped with a pulsed plasma thruster (PPT) and a high-gain communication antenna employing a full 3-axis active attitude control subsystem. The PPT aims to operate for an extended period of time to provide enough ∆V to maintain altitude for more than 3 months of operation in low earth orbit (LEO). At the same time, a novel high frequency K-band reflect array antenna will complete multiple downlinks of up to 1 Mb/s while flying over the ground station. The ADCS requirements are to estimate the current orientation and position of the spacecraft and provide reliable reorientation control across all attitude modes. Specifically, ADCS shall maintain pointing accuracy of 2◦ during ground station flyovers, and 4◦ accuracy during velocity-pointing maneuvers for PPT operation. For reorientation control, the ADCS employs two control algorithms. One implements a large angle reorientation of a solar panel bore-sight vector in a geodesic manner, while the other carries out a reorientation in the presence of an attitude forbidden zone due to PPT exhaust plumes. To validate the controller, simulations are performed in a closely modeled space environment and the results are compared with conventional algorithms.