Lessons from implementation of beacon spacecraft operations on Deep Space One

A new approach to mission operations has been flight validated on NASA's Deep Space One (DS1) mission that launched in October 1998. The beacon monitor operations technology is aimed at decreasing the total volume of downlinked engineering telemetry by reducing the frequency of downlink and the volume of data received per pass. Cost savings are achieved by reducing the amount of routine telemetry processing and analysis performed by ground staff. With beacon monitoring, the spacecraft will assess its own health and will transmit one of four subcarrier frequency tones to inform the ground how urgent it is to track the spacecraft for telemetry. If all conditions are nominal, the tone provides periodic assurance to ground personnel that the mission is proceeding as planned without having to receive and analyze downlinked telemetry. If there is a problem, the tone will indicate that tracking is required and the resulting telemetry will contain a concise summary of what has occurred since the last telemetry pass. The beacon technology has been proven successful on DS1 through a series of tone tests and data summarization experiments. This collection of experiments was called the DS1 Beacon Monitor Experiment or BMOX. There are important lessons still to be learned from this experiment that can be applied to future spacecraft missions.