Positively Verifying Mating of Previously Unverifiable Flight Connectors

Goddard Space Flight Center, Greenbelt, Maryland

Current practice is to uniquely key the connectors, which, when mated, could not be verified by ground tests such as those used in explosive or non-explosive initiators and pyro valves. However, this practice does not assure 100-percent correct mating. This problem could be overcome by the following approach.

Errors in mating of interchangeable connectors can result in degraded or failed space mission. Mating of all flight connectors considered not verifiable via ground tests can be verified electrically by the following approach. It requires two additional wires going through the connector of interest, a few resistors, and a voltage source (see figure). The test-point voltage Vtp when the connector is not mated will be the same as the input voltage, which gets attenuated by the resistor Rl when the female (F) and male (M) connectors are mated correctly and properly. The voltage at the test point will be a function of Rl and R2. Monitoring of the test point could be done on ground support equipment (GSE) only, or it can be a telemetry point. For implementation on multiple connector pairs, a different value for Rl or R2 or both can be selected for each pair of connectors that would result in a unique test point voltage for each connector pair. Each test point voltage is unique, and correct test point voltage is read only when the correct pair is mated correctly together. Thus, this design approach can be used to verify positively the correct mating of the connector pairs. This design approach can be applied to any number of connectors on the flight vehicle.

This work was done by R.K. Chetty Pandipati and Marlon Enciso of Goddard Space Flight Center. GSC-15896-1

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