Mars Express TTC Contingency Operations - Hoping for the Best, Preparing for the Worst

摘要

The Telemetry, Tracking and Commanding (TT&C) system on any spacecraft is critical to operations as it is the only thing linking us to the spacecraft from ground. Therefore the response to a failure in the TT&C system especially requires a high level of autonomy and preparation both on board and on ground given that any failure could temporarily or permanently sever the link to the spacecraft and cut-off any opportunity to recover or troubleshoot from ground. There are two different kinds of failure that can occur in any TT&C system - a failure on the receive chain (uplink) or a failure on the transmit chain (downlink). The response and operational approach for each kind of failure are very different and require a customized solution for each. In both cases the traditional method of analyzing telemetry, determining a response and recovering with telecommands cannot work completely.