Stochastic Cable Harness Coupling to Electric Fields in Spacecraft Cavities

The proposed innovation is a new software tool that overcomes the present obstacles to simulation-based tailoring of EMC environment specifications for all space flight electronics.nbsp;NASArsquo;s baseline EMC qualification process is for all electronics systems, subsystems and components to be test-qualified to a single, universal MIL-STD-461 specification. However, this is not necessarily a safe or cost-effective process. The MIL STD may underestimate some known threats specific to a NASA mission. Successive revisions to MIL-STD-461 have increased radiation susceptibility levels by more than 40dBnbsp;to accommodate the rapidly evolving EMC threats from ever-higher frequency digital electronics. But this in turn means that the MIL STD may substantially overstate the maximum expected environment for other NASA missions, precluding the use of lower cost, commercial-of-the-shelf (COTS) electronics.The proposednbsp;innovationnbsp;uses asymptotic statistics to greatly reduce the simulation task complexity, making it feasible for NASA engineers to predict and mitigate cable harness currents induced by coupling with strong cavity electric fields for all spacecraft and launch vehicle programs. Phase II will deliver a customization of RobustPhysicsrsquo; hybrid electromagnetic field modelling software for NASA electromagnetic compatibility (EMC) applications. The hybrid solution uses rigorous physics to couple a statistical model of the 3D electric field in cavities with a deterministic transmission line / transfer matrix model of currents in a cable harness. nbsp;The reduced order, statistical power balance model for 3D electric fields in complex connected cavities ndash; including launch vehicle fairings - was validated in the Phase I STTR.