SEVERAL NEW HORIZONS (NH) OBSERVATIONS MAKE NECESSARY A NEW EXAMINATION OF UPPER ATMOSPHERIC PROPERTIES OF THE PLUTO-CHARON SYSTEM. PLUTO S UPPER ATMOSPHERE WAS COLDER THAN EXPECTED PRE-ENCOUNTER PERHAPS DUE TO TRACE SPECIES UNDERGOING RADIATIVE COOLING THE ESCAPE RATE WAS LOWER THE METHANE/NITROGEN FRACTIONATION GREATER AND THE SOLAR WIND PENETRATED CLOSER TO PLUTO. IN FACT THE SOLAR WIND INTERACTION OCCURRED INSIDE OF CHARON S ORBITAL DISTANCE. THERE WAS ALSO NO OBSERVED ATMOSPHERE ON CHARON THOUGH THERE ARE SURFACE COLORATIONS SUGGESTIVE OF INTER-BODY GAS TRANSFER AND MIGRATION OVER CHARON S SURFACE. PLUTO S SURFACE WAS OBSERVED TO SHOW RECENT POSSIBLE LIQUID FLOWS SUGGESTING PERIODS OF APPRECIABLY GREATER ATMOSPHERIC COLUMN PERHAPS DUE TO PLUTONIAN MILANKOVICH CYCLES AND IMPLYING VERY DIFFERENT ESCAPE RATES/PROCESSES IN THE PAST. THE KNOWLEDGE GAP IMPLIED BY THESE AND OTHER NH OBSERVATIONS PROVIDES THE MOTIVATION FOR THIS PROPOSAL. WE HAVE CREATED A FULLY THREE DIMENSIONAL FULLY RESOLVED DIRECT SIMULATION MONTE CARLO (DSMC) MODEL OF PLUTO S N2/CH4 UPPER ATMOSPHERE INCLUDING GAS TRANSFER TO/FROM CHARON AND ESCAPE FROM THE SYSTEM (HOEY ET AL. 2017). WE PRESENTED PRELIMINARY RESULTS FOR DIFFERENT POSSIBLE LOWER BOUNDARY CONDITIONS FOR THE PROCESS OF ATMOSPHERIC TRANSPORT FROM PLUTO TO CHARON AND ESCAPE FROM THE SYSTEM AND MATCH THE 5-TO-6 10^25 S 1 ESCAPE RATE OBSERVED BY NH (BAGENAL ET AL. 2016 GLADSTONE ET AL. 2016). IN THE COURSE OF OTHER WORK WE HAVE RECENTLY DEVELOPED MORE SOPHISTICATED MODULES FOR OUR DSMC CODE SO IT CAN NOW ACCOMMODATE MOLECULAR COLLISIONAL CHEMISTRY AND PHOTOCHEMISTRY INCLUDING CHARGED PARTICLES. WE HAVE ALSO DEVELOPED THE ABILITY TO SIMULATE LINEBY- LINE RADIATIVE TRANSPORT IN 3-D WITHIN THE DSMC CODE USING A PHOTON MONTE CARLO PROCEDURE FULLY COUPLED TO THE MOLECULAR DSMC MODELS. OUR GROUP NOW ALSO HAS THE ABILITY TO USE THE SOPHISTICATED 1-D RADIATIVE TRANSFER CODE PRESENTED IN MAHIEUX ET AL. (2015 2017). FURTHERMORE WE CAN NOW MODEL THE EFFECTS OF DIURNAL TEMPERATURE VARIATIONS IN PLUTO S UPPER ATMOSPHERE AND ON CHARON S SURFACE. WE PROPOSE TO GREATLY EXPAND ON OUR INITIAL MODELING USING THESE MORE SOPHISTICATED MODELS NOW AVAILABLE AND CORRELATE RESULTS WITH THE NH OBSERVATIONS PARTICULARLY THOSE OF THE UV SPECTRA (ALICE) THE SOLAR WIND (SWAP) CHARON SURFACE PROPERTIES (LORRI) AND FIELDS AND PARTICLES (PEPSSI). WE WILL ALSO INDIRECTLY USE REX OBSERVATIONS OF THE LOWER ATMOSPHERE AS THEY ARE INCORPORATED INTO THE LITERATURE MODELS FROM WHICH WE DRAW OUR BOUNDARY CONDITIONS. THE PROPOSED WORK IS THUS RELEVANT TO THE NFDAP IN THAT IT INTEGRATES A VARIETY OF NH OBSERVATIONS TO MODEL THE PLUTO/CHARON ATMOSPHERE A KEY TARGET OF THE NH MISSION TO EXTEND THE SCIENTIFIC YIELD OF THE NFDAP PROGRAM. USING THESE MODELS AND NH DATA WE AIM TO GREATLY IMPROVE UNDERSTANDING OF THE UPPERMOST PORTIONS OF THE PLUTO/CHARON ATMOSPHERE PARTICULARLY AS REGARDS TO THE NATURE OF INTERBODY TRANSFER AND ESCAPE PROCESSES.