Neural Networks Monitor the Health of Space Shuttle Valve

The gaseous hydrogen flow control vale (GH2FCV; see Figure 1) is a critical space shuttle component that controls the pressure of the hydrogen external tank during launch and ascent to orbit. The valve is one of the components that are to be monitored by the Integrated Vehicle Health Monitoring (IVHM) system. The GH2FCV is a two-position valve that is actuated by electromagnetic force acting against a return spring. In the de-energized position, the gaseous hydrogen flow is high; when the valve is energized, flow is reduced. There are three such valves on the shuttle, one connected to each of the three main engines and manifolded together to return hydrogen gas to the external tank (see Figure 2).