OBJECTIVES AND SIGNIFICANCE: WE PROPOSE HERE TO INVESTIGATE NUMERICALLY ANALYTICALLY AND WITH ANALYSIS OF SPACECRAFT IMAGES THE PHYSICS OF DUSTY RINGS. WE WILL FOCUS OUR ATTENTION ON ONE OF THE MOST INTERESTING MANIFESTATIONS OF DUST IN THE SOLAR SYSTEM - SPOKES IN SATURN'S B RING RAPIDLY-FORMED RADIAL MARKINGS THAT HAVE PUZZLED PLANETARY SCIENTISTS SINCE THEIR DISCOVERY OVER 35 YEARS AGO. IN THIS PROPOSAL WE SEEK TO ELUCIDATE THE DETAILED WORKINGS OF B RING SPOKES; OUR PRIMARY GOAL IS THE CONSTRUCTION OF A NEW PARADIGM FOR SPOKE ORIGIN AND EVOLUTION. VOYAGER AND CASSINI DATASETS ON SPOKES ARE EXTENSIVE AND SHOW A WIDE RANGE OF MORPHOLOGY AND PHENOMENOLOGY THAT HAS NEVER BEEN FULLY EXPLAINED. SATURN'S PROMINENT RING SYSTEM IS THE SOLAR SYSTEM ARCHETYPE AND ITS MYSTERIOUS AND GHOSTLY SPOKES DESERVE RENEWED SCRUTINY. OUR FINDINGS WILL GREATLY IMPROVE THE UNDERSTANDING OF THE DYNAMICS OF DUST IN SATURN'S MAIN RINGS AND WILL RESOLVE A DECADES-OLD PUZZLE. MOST OF THE PROCESSES THAT WE WILL ELUCIDATE WILL BE GENERAL AND ACCORDINGLY WILL HAVE RAMIFICATIONS FOR THE DUSTY RINGS SYSTEMS OF THE OTHER GIANT PLANETS. STUDYING DUSTY RINGS TEACHES US ABOUT EROSIONAL AND ACCRETIONAL PROCESSES THAT HAVE BEEN ACTIVE OVER THE AGE OF THE SOLAR SYSTEM AND HAVE PLAYED A ROLE IN SCULPTING THE RING SYSTEMS OF THE GIANT PLANETS INTO THE FORMS THAT THEY TAKE TODAY. OUR STUDY WILL GREATLY IMPROVE THE COMMUNITY'S UNDERSTANDING OF THE EVOLUTION OF SATURN'S MAIN RING SYSTEM THE BEST ANALOG THAT WE HAVE TO DISKS FROM WHICH THE PLANETS AND SATELLITES FORM. RELEVANCE TO THE CASSINI DATA ANALYSIS PROGRAM: WE PLAN TO UTILIZE THE EXTENSIVE DATA OBTAINED BY THE CASSINI ISS CAMERAS TO QUANTIFY THE RANGE OF STRUCTURES AND INTENSITIES VISIBLE IN B RING SPOKES. OUR PRIMARY GOAL IN THIS WORK IS TO DEFINE KEY DYNAMICAL PROCESSES OPERATING IN SATURN'S ARCHETYPAL RING SYSTEM - SPOKE FORMATION AND EVOLUTION - FOR WHICH NO ADEQUATE MODEL CURRENTLY EXISTS. THE RESEARCH PROPOSED HERE FALLS WITHIN THE SCOPE OF NASA CDAP DUE TO ITS SIGNIFICANT USE OF DATA RETURNED BY THE ISS INSTRUMENT. BESIDES MAKING USE OF CASSINI DATA OUR THEORETICAL STUDY WILL ALSO SIGNIFICANTLY FACILITATE THE INTERPRETATION OF DATA FROM THE CASSINI MISSION THEREBY STRONGLY ENHANCING THE SCIENTIFIC RETURN FROM THE MISSION. THIS PROPOSAL MIGHT ALSO BE APPROPRIATE FOR SOLAR SYSTEM WORKINGS BUT WE JUDGE THE CASSINI DATA ANALYSIS COMPONENT AS WELL AS THE VALUE OF THE RESEARCH TO CASSINI SCIENTISTS TO BE IMPORTANT ENOUGH TO MAKE CDAP THE LOGICAL FIT. WE FURTHER EXPECT THAT CASSINI DATA ON THE LIT AND UNLIT SIDES OF SATURN'S RINGS AND AT MULTIPLE EPOCHS WITH DIFFERENT RING OPENING ANGLES WILL BE PARTICULARLY DIAGNOSTIC IN CONSTRAINING OUR SPOKE MODELS. FINALLY WE WILL MAKE SIGNIFICANT USE OF THE LARGE AND EXPANDING CASSINI ISS DATASET EFFICIENTLY UTILIZING THE TOOLS AND EXPERTISE OF CO-I MATT HEDMAN A CASSINI DATA SCIENTIST WITH YEARS OF EXPERIENCE WITH BOTH THE ISS AND VIMS INSTRUMENTS.