Redundancy design philosophy for catastrophic loss protection

To ensure high flight safety and mission reliability in flight-critical electronics of aerospace vehicles, a redundancy design technique named brick wall is discussed. Basically, the technique proposes triplex redundant, independent paths where each path can self-monitor its own health (by using a comparison scheme within each path). Upon a fault detection, the whole path is taken offline. The inherent high redundancy allows the achievement of stringent flight safety and mission reliability goals. The design also protects against hidden/unknown failure modes and sneak circuits. The design tradeoffs are made against higher maintenance rates, cost, and weight