A Command and Data Handling unit for pico-satellite missions

This paper outlines the design and implementation of phase two of the command and data handling (CDH) unit for the WinCube project. WinCube is a multi-year, multi-disciplinary project conducted at the University of Manitoba in which students from different departments participate in the design of a CubeSat. The purpose of the WinCube project is to provide an opportunity for engineering students to design and implement a space-ready satellite. The project also acts as a vessel for a high school science experiment, which will run an experiment while in space, and relay results down to a satellite base station. The CDH unit must manage the operations and internal communications of the various units inside the satellite. This unit includes a power management application, serial communications protocols to relay information, and a trustworthy timing system. The power management application must monitor the state of the battery, the output of the solar panels, as well as control the amount of power provided to each of the primary units. Serial communications are used to interact with other devices on the satellite. Finally, an external real time clock and watchdog timer were used to enhance the reliability of the system. Special measures were taken to protect the CDH unit from the harsh operating environment and to monitor the health of the system beyond temperature and battery readings by performing periodic tests of components.