This project develops an Attitude Determination and Control (ADC) subsystem for a six-unit CubeSat in an extreme low Earth orbit (eLEO) mission performing atmospheric neutral and ion mass spectrometry. The selection of sensors and actuators were evaluated and updated from a previous mission. The performance of algorithms used for detumble, initial attitude determination, and attitude maintenance was evaluated using MATLAB, Simulink, and Systems Tool Kit (STK) simulations. In order to conduct this evaluation, in-depth Simulink models of spacecraft attitude dynamics and control were developed which consider sensor noise and refresh rates for a GPS receiver, gyroscope, magnetometer, and two-axis sun sensors, as well as actuator limitations for reaction wheels and magnetorquers
