The University of Illinois is developing a CubeSat bus, known as IlliniSat-2, which will be capable of achieving 3-axis attitude control via magnetic torque coils and attitude determination via Kalman-filtered magnetometer data with an optional Sun vector measurement. This innovative new attitude determination and control (ADC) method is more sophisticated than those traditionally employed on CubeSats and will require extensive pre-flight testing to ensure that IlliniSat-2 functions properly after it is launched. To accommodate such testing, a hardware-in-the-loop ADC simulation suite, known as CubeSim, is being developed. CubeSim uses a large triaxial Helmholtz coil, known as the HC3, to dynamically manipulate the magnetic field around a CubeSat to simulate an orbital environment. In the case of an IlliniSat-2 bus, the HC3 testbed allows the CubeSat to determine its attitude in real-time. CubeSim will also receive control feedback from the CubeSat and update the simulated attitude accordingly. This thesis will discuss the development of CubeSim, including the theory and design of the HC3 and the associated software interfaces. Results from initial simulations and testing will be presented and the path for future work will be discussed
