Evaluation of numerical bus systems used in rocket engine test facilities

Abstract

Currently measurement, control and com- mand system (MCC) for rocket engine test facilities use classical connections for mea- surements and also for control and command systems of the test bench and the engine. At the moment numerical bus systems are mainly used inside the MCC system or to interface stages (MIL STD-1553). In future applications, engine and stage components are interfaced by numerical bus systems in- stead of direct wiring. In addition the com- mon known MIL-STD-1553 bus system will be compared with modern approaches. This paper provides an overview of public available information concerning bus systems used in aeropspace applications. The evalu- ation criteria are chosen with respect to the use in rocket engine test benches and launch vehicles. The questions asked to each bus are focussed on reliability and performance since the data bus network is as safety-critical for the test bench as it is for the launch vehicle. Beside interfacing the engine or stage avionics, numerical bus systems also allow MCC systems to react more flexible on changed requirements for acquisition, control and health monitoring. Possible extensions and constraints, to include such systems in existing MCC systems, are also shown in this paper.