MARS WAS ONCE RICH WITH LIQUID SURFACE WATER BUT THE LOSS OF THE PLANET'S ATMOSPHERE OVER TIME HAS REMOVED ITS ABILITY TO SUSTAIN SUCH FEATURES. MUCH OF THIS LOSS WAS DUE TO THE ESCAPE OF ATMOSPHERIC PARTICLES TO SPACE WHICH CONTINUOUSLY OCCURS THROUGHOUT THE MARTIAN SYSTEM. STUDYING ATMOSPHERIC ESCAPE AT MARS THEREFORE AFFECTS OUR UNDERSTANDING OF THE PLANET'S PAST HABITABILITY AND NASA'S MAVEN MISSION WAS DESIGNED SPECIFICALLY TO EXAMINE THE VARIETY OF PROCESSES THAT DRIVE THIS ESCAPE. ION ESCAPE FROM CRUSTAL MAGNETIC CUSPS IS ONE SUCH PROCESS THAT MAY HAVE CONTRIBUTED SUBSTANTIALLY TO MARTIAN ATMOSPHERIC LOSS OVER TIME. THIS MECHANISM INVOLVES THE ENERGIZATION AND OUTFLOW OF CHARGED PARTICLES FROM MARTIAN CRUSTAL MAGNETIC FIELD REGIONS POCKETS OF MAGNETISM THAT WERE LOCKED INTO MARS' CRUST WHEN THE PLANET POSSESSED A GLOBAL DYNAMO. SPACECRAFT MEASUREMENTS HAVE SHOWN THAT THESE REGIONS EXHIBIT ENHANCED LEVELS OF PARTICLE OUTFLOW BUT NO STUDY HAS YET DETERMINED WHAT THE RELATIVE CONTRIBUTION OF THIS OUTFLOW IS TO THE OVERALL LOSS OF ATMOSPHERE FROM MARS. THE WORK I PROPOSE HERE WILL ADDRESS THIS QUESTION DIRECTLY USING DATA FROM THE MAVEN SPACECRAFT TO STUDY THE GLOBAL-SCALE EFFECTS OF ION OUTFLOW FROM CRUSTAL MAGNETIC FIELD CUSPS. I WILL USE DIRECT MEASUREMENTS OF THESE CUSPS TO ANALYZE THEIR STRUCTURE AND VARIABILITY. I WILL CHARACTERIZE THE SIZE AND SPREAD OF CUSPS AS WELL AS THE MAGNITUDE OF THEIR ESCAPING ION FLUXES AND BY COMBINING THESE MEASUREMENTS I WILL CALCULATE WHAT FRACTION OF GLOBAL ION ESCAPE ORIGINATES FROM CRUSTAL MAGNETIC FIELD REGIONS. THIS WILL PROVIDE INSIGHT INTO THE INFLUENCE OF CRUSTAL MAGNETIC FIELDS ON MARS' ATMOSPHERIC ESCAPE AND PLANETARY EVOLUTION AS WELL AS INTO THE IMPORTANCE OF PLANETARY MAGNETIC FIELDS IN GENERAL FOR THE RETENTION OF SUBSTANTIAL ATMOSPHERES. IN THIS WAY MY WORK WILL DIRECTLY CONTRIBUTE TO THE OBJECTIVES OF THE MAVEN MISSION AND WILL HAVE IMPLICATIONS PERTAINING TO NASA'S STRATEGIC GOALS OF UNDERSTANDING THE PHYSICAL PROCESSES THAT AFFECT OUR SOLAR SYSTEM AND CHARACTERIZING THE EVOLUTION OF SOLAR SYSTEM BODIES