OUR SCIENCE QUESTION IS: CAN DRIFT-BOUNCE DISPERSION OF MICROBURSTS EXPLAIN THE RECENT SURPRISING OBSERVATION OF 30-60 KM FINE SCALE PERSISTENT (>60 SECONDS) STRUCTURES IN>35 KEV ELECTRONS PRECIPITATING INTO THE EARTH S ATMOSPHERE. IN BLAKE AND O BRIEN [2016 JGR] WE REPORTED OBSERVATIONS OF THESE STRUCTURES FROM THE UNIQUE AEROCUBE-6 (AC6) MISSION. AC6 IS AN AEROSPACE CORPORATION TECHNOLOGY DEMONSTRATION MISSION WITH SPONSORSHIP FROM THE US AIR FORCE SPACE AND MISSILE SYSTEMS CENTER. LAUNCHED IN JUNE 2014 AND STILL OPERATING AC6 CONSISTS OF TWO 0.5U CUBESATS EACH EQUIPPED WITH THREE MICRODOSIMETERS SAMPLED AT UP TO 10 HZ. THE TWO VEHICLES ARE IN SIMILAR 620 KM X 700 KM ORBITS AT A 98 DEGREE INCLINATION. THE IN-TRACK SEPARATION OF THE VEHICLES VARIES OVER THE MISSION AND CAN BE CONTROLLED VIA DIFFERENTIAL DRAG. THE FINE STRUCTURES WERE OBSERVED IN THE DRIFT LOSS CONE (DLC) WHERE LOCAL PARTICLES CAN DRIFT PART WAY AROUND THE EARTH BEFORE BEING LOST TO THE ATMOSPHERE IN THE SOUTH ATLANTIC ANOMALY (SAA). THE INDIVIDUAL TEMPORAL FEATURES ARE A FEW SECONDS LONG TOO LONG TO BE BOUNCE PHASE STRUCTURE AND HAVE A ~30 KM LATITUDINAL EXTENT. THE FACT THAT THE SAME FEATURES ARE STILL PRESENT AFTER ~60 SECONDS SUGGESTS NOT ONLY THAT THEY ARE SPATIAL AND BOUNCE PHASE MIXED BUT ALSO THAT THEY HAVE A LONGITUDE EXTENT OF AT LEAST 60 KM AS ANYTHING SMALLER WOULD HAVE DRIFTED AWAY BEFORE THE ARRIVAL OF THE SECOND SPACECRAFT. WE WILL SYSTEMATICALLY ANALYZE THE 30-60 KM STRUCTURES AND ATTEMPT TO SIMULATE THEIR FORMATION. AT A GIVEN ALTITUDE THE BOUNCE LOSS CONE (BLC) IS A GEOGRAPHIC REGION ROUGHLY MAGNETICALLY CONJUGATE TO THE SAA WHERE EVEN LOCALLY MIRRORING PARTICLES WILL BE LOST TO THE ATMOSPHERE WHEN THEY BOUNCE INTO THE OPPOSITE HEMISPHERE. THEREFORE PARTICLES OBSERVED IN THE BLC HAVE BEEN PITCH ANGLE SCATTERED ON THE LOCAL MAGNETIC FIELD LINE. BY EXAMINING THE TEMPORAL STRUCTURE OF BLC PRECIPITATION EVENTS AT SEVERAL DIFFERENT SPACECRAFT SEPARATIONS FROM ~0 KM TO ~300 KM WE CAN DETERMINE THE INITIAL TRANSVERSE (SPATIAL) AND BOUNCE PHASE (TEMPORAL) PROPERTIES OF THE SCATTERED PACKETS OF ELECTRONS. TO SUPPORT THIS DATA ANALYSIS OUR PROPOSAL INCLUDES TWO YEARS OF SPECIAL AC6 OPERATIONS IN BLC CAMPAIGNS AND DRIFT LOSS CONE (DLC) CAMPAIGNS. DURING THE SCIENCE PHASE THE SPACECRAFT SEPARATION WILL GRADUALLY SEPARATE FROM ~0 KM TO 300 KM AND THEN RETURN TOGETHER. DATA COLLECTION WILL BE ALTERNATELY MAXIMIZED IN THE BLC OR DLC TO STUDY PRISTINE PARTICLES IN THE BLC OR PROCESSED ONES IN THE DLC. USING ESTABLISHED ELECTROMAGNETIC FIELD MODELS WE WILL TRACE PARTICLES FROM A MODEL SCATTERED PACKET FORWARD IN TIME TO DETERMINE WHETHER BOUNCE PHASE MIXING AND DRIFT DISPERSION CAN PRODUCE THE PERSISTENT 30-60 KM SPATIAL STRUCTURES. IF THIS HYPOTHESIS EXPLAINS THE OBSERVATIONS THEN IT ALSO REVEALS AN IMPORTANT SPATIAL SCALE OF THE SOURCE REGION OF MICROBURSTS AND LIKELY CHORUS. OBSERVATIONAL STUDIES INDICATE THAT THE CHORUS SOURCE REGION IS COHERENT OVER TRANSVERSE SCALES OF UP TO 100 KM WHILE A POTENTIALLY LARGER REGION (~3000 KM) MAY BE UNSTABLE AND GENERATING CHORUS SIMULTANEOUSLY BUT NOT COHERENTLY. THE PROPOSED STUDY WOULD PROVIDE A STRONG OBSERVATIONAL CONSTRAINT ON THE SIZE OF PRECIPITATION FROM THAT LARGER REGION WHICH IS THE RELEVANT SCALE SIZE FOR DETERMINING THE AMOUNT OF ELECTRONS LOST IN A SINGLE MICROBURST EPISODE. THE PROPOSAL ADDRESSES THE DECADAL SURVEY S KEY SCIENCE GOAL 2 WHICH SPECIFICALLY CALLS OUT UNDERSTANDING CHARGED-PARTICLE ACCELERATION SCATTERING AND LOSS WHICH CONTROL THE INTENSIFICATION AND DEPLETION OF THE RADIATION BELTS IS THEREFORE A PRIORITY OF SOLAR AND SPACE PHYSICS. CHARGED-PARTICLE LOSS IS AT THE CORE OF THE PROPOSAL WITH IMPLICATIONS FOR ACCELERATION VIA CHORUS IN ORDER TO FACILITATE MAXIMUM SCIENTIFIC RETURN ON THE AC6 DATA WE PROPOSE TO PROVIDE A COMPLETE LEVEL 2 MISSION ARCHIVE IN STANDARD NASA COMMON DATA FORMAT TO THE SPACE PHYSICS DATA FACILITY.