A PARTICULATE MONITOR FOR COMET AND PLANETARY ATMOSPHERES

FUTURE MISSIONS TO COMETS AND PLANETARY ATMOSPHERES REQUIRE PARTICULATE MONITORING INSTRUMENTATION TO FULFILL A NUMBER OF SCIENTIFIC AND ENGINEERING MEASUREMENT NEEDS. THERE IS ONLY ONE INSTRUMENT CAPABLE OF SPACECRAFT OPERATION WHICH CAN PROVIDE A DIRECT MEASUREMENT OF PARTICULATE MASSES WITH A LOADING RANGE OF SIX ORDERS OF MAGNITUDE. THIS INSTRUMENT IS THE TAPERED ELEMENT OSCILLATING MICROBALANCE (TEOM). A TEOM WITH A COLLECTION SUBSTRATE CAN MEASURE SUB-NANOGRAM PARTICLES IN A COMET RENDEZVOUS MISSION, AND A TEOM WITH A FILTER CARTRIDGE CAN MONITOR PARTICULATES IN A PLANETARY ATMOSPHERE. THE INSTRUMENTATION PROVIDES REAL-TIME MEASUREMENTS, AND CAN BE TEMPERATURE CYCLED TO PROVIDE A MEASURE OF VOLATILE AND NON-VOLATILE COMPONENTS OF THE PARTICULATES. PHASE I OF PROJECT IS INTENDED TO ESTABLISH THE LIMITS OF MASS RESOLUTION CAPABILITY OF THE TEOM UNDER RELEVANT SPACE AND PLANETARY ATMOSPHERE CONDITIONS. THE GOAL OF PHASE II IS THE PRODUCTION OF PROTOTYPES WHICH CAN SERVE THE PARTICULATE MEASUREMENT TASKS OF THE VARIOUS MISSIONS.