Command and Data Handling System

The Command and Data Handling (C&DH) system is the ILLINISAT-2's brain, needed to sustain our satellite for the 80% of time in which it is beyond our radio's reach. Our system is capable of running complex and computationally intensive software, which is required to maintain our advanced systems and the payload. These calculations are run on a highly efficient TI OMAP processor, similar to what could be found in today's latest smartphones. Our particular processor is not only power efficient, but with both an ARM and a DSP core, we are able to intelligently split up work between the two different cores to optimize our processing efficiency.

Our processor is embedded on a custom circuit board which connects the processor to a variety of other peripherals within the satellite. The board is connected to all the various sensors, power control/monitoring hardware, and communications equipment. We also have a dedicated USB and serial port for the payload to utilize. By routing this information to the processor, we are able to take necessary actions to ensure the survival and success of the mission.

We have developed software to accomplish our goals. Our processor runs a customized stripped-down Linux kernel and a daemon (iond) which runs in the background: it decides which actions need to be taken based on temperature, battery life, satellite orientation, or radio communication. For example, when the daemon notices that the we are not properly aligned, it will run the appropriate program to perform the attitude calculations, and then will use that data in order to reposition the satellite.

Externally, our system is critical in its interaction with the payload. We offer a dedicated USB and serial port for the payload to utilize so that it, too, may interact with the processor and even run their mission's software.

Copyright University of Illinois at Urbana-Champaign 2008