Event Priority Instrumentation System for Nuclear Experiments on Scientific Satellites

The number of information bits per unit time, or data rate, which can be telemetered back to earth from a scientific satellite is limited by restrictions on weight, volume and power. Thus, each experimenter (generally one of many) is allotted a very limited data rate capability. In nuclear experiments, where a wide variety of events may occur per unit time, use of this rate capability may be optimized by selection of events on a priority basis. Described here is an event priority instrumentation system developed for use in scientific satellites. The system allows for the selection of the highest priority event occurring during a telemetry sequence. Also, provision is made for periodically changing the order of priority. All circuitry was designed and developed to minimize weight, volume and power drain and to maintain stable characteristics while unattended for periods as long as one year. The operating temperature range is -20°C to 60°C.