Housekeeping Data: Can You Afford Not to Compress It?

Previous work at ESA/ESOC showed that spacecraft housekeeping telemetry contains significant amounts of information redundancy. A simple algorithm was proposed that removed this redundancy almost as effectively as well known commercial products like zip. However conventional wisdom says that even if stored housekeeping telemetry can be compressed - it should not be. At first glance the arguments appear reasonable; it would reduce the robustness of the ground space link, it would make using existing infrastructure more difficult, it would be complicated to implement as on-board software or too resource hungry. Finally there is the old argument that as housekeeping telemetry is typically only a fraction of the total mission data it would not be worth compressing. In this paper we intent to turn that conventional wisdom on its head as we make the move from theory to reality. We test our algorithm across a variety of mission types, solve the risk problem, propose an architecture that reuses existing infrastructure and implement the algorithm on real hardware using real data. Finally we show that there are additional advantages to using this compression technique besides freeing bandwidth and these can be even more significant than the obvious advantages. Can you afford not to compress housekeeping data? The results in this paper might change your answer.