A distributed spacecraft thermal control architecture using the Dallas Semiconductor MicroLan products

Distributing the functionality associated with low-level sensing and actuation, particularly for highly granular functions like thermal control, has been difficult because of the overhead associated with local signal processing and communications functions. The MicroLAN^TM serial data protocol and architecture implemented by the Dallas Semiconductor DS1820 Digital Thermometer and DS2407 Dual Addressable Switch provide an interesting approach implementing this functionality on spacecraft. Very low-power devices provide simple sophisticated serial bus interfaces which allow significant reductions in configuration management and cable mass. A detailed application architecture for temperature sensing and control is presented. Radiation effects test data, limitations and mitigation techniques are discussed. An application which demonstrates the virtues of one device, the DS1820, on the New Millennium Program´s Deep Space One mission is described