THE GOAL OF THIS PROPOSAL IS TO CONDUCT A NOVEL ANALYSIS OF MAVEN IUVS MEASUREMENTS OF H EMISSION AT 121.6 NM (LYMAN ALPHA) FROM THE MARTIAN H CORONA IN ORDER TO PROVIDE A MORE REALISTIC QUANTIFICATION OF THE GLOBAL TIME-DEPENDENT DISTRIBUTION OF THE H CORONA AND TO ENABLE A MORE ACCURATE ASSESSMENT OF ITS ONGOING LOSS TO INTERPLANETARY SPACE. THIS EFFORT WILL USE A STATE-OF-THE-ART RADIATIVE TRANSFER MODEL DEVELOPED BY THE PI AND CO-PI FOR ANALYSIS OF H LYMAN ALPHA EMISSION AS MEASURED IN THE EARTH S CORONA BY NUMEROUS NASA HELIOPHYSICS MISSIONS (TIMED TWINS AND IMAGE). WE WILL EXAMINE THE SENSITIVITY OF MARTIAN ESCAPE FLUX CALCULATIONS TO THE SPECIFIC DENSITY PARAMETERIZATION ADOPTED IN THE INVERSION SCHEME IMPLEMENTING BOTH PHYSICS-BASED AND MATHEMATICALLY-DRIVEN FUNCTIONAL FORMS INCLUDING A NON-PARAMETERIZED INVERSE MODEL. WE WILL EXPLICITLY EVALUATE THE SALIENCE OF SATELLITE ATOM SPECIFICATIONS AS A MORE ACCURATE TREATMENT OF THE THREE-DIMENSIONAL STRUCTURE OF THE H DISTRIBUTION. THIS EFFORT PROMISES TO SIGNIFICANTLY ADVANCE UNDERSTANDING OF THE MARTIAN ATMOSPHERE AND CLIMATE WITH DIRECT RELEVANCE TO BOTH THE OVERALL MAVEN MISSION AND NASA STRATEGIC PRIORITIES.