Although the ATV onboard computer is fault tolerant, the complexity of the mission does not allow the prevention of and recovery all possible types of mission failures. Special features of the onboard system would allow detecting and forecasting failures, isolating them and proposing and executing recovery actions, but only for those types of contingencies anticipated during system design. The failure detection and recovery features are linked to both mission safety and mission success. Used on ground, GOAS is a software tool to monitor the ATV mission and intervene in case of a problem. GOAS provides complex command and control capabilities to replan the entire mission if necessary.
Reliability is crucial to space applications.
The software never crashes or misbehaves, despite the fact that both systems were designed to run nonstop for weeks or even months. Performance is the definitive factor in measuring real-time critical software. That is, they receive data from the spacecraft, display it and send it back to the satellite, all in real time. Everything runs within the specified communications rate between craft. Software portability is of vital importance for upgrades and applications enhancement.