THE ORIGIN OF THE TWO MOONS OF MARS PHOBOS AND DEIMOS REMAINS A MAJOR UNSOLVED MYSTERY IN OUR UNDERSTANDING OF PLANET AND SATELLITE FORMATION. EXISTING OBSERVATIONS OF PHOBOS AND DEIMOS ARE INSUFFICIENT TO DETERMINE WHICH OF THE MANY PROPOSED MODELS FOR THEIR ORIGIN AND MODIFICATION HISTORY IS CORRECT. PROPOSED ORIGIN MODELS INCLUDE CAPTURE OF ASTEROIDS CONTEMPORANEOUS FORMATION WITH MARS AND FORMATION FROM AN IMPACT-GENERATED DEBRIS DISK. THE LACK OF A DEFINITIVE ORIGIN MODEL ALSO HAS MAJOR IMPLICATIONS FORHUMAN EXPLORATION AS THE AMOUNT OF EXTRACTABLE RESOURCES NEEDED TO AID IN HUMAN EXPLORATION OF MARS IS TIED TO THE MOONS FORMATION AND EVOLUTION. THEREFORE THE POTENTIAL FOR RESOURCE EXPLOITATION OF THE MOONS OF MARS IS HIGHLY UNCERTAIN. PHOBOS AND DEIMOS LACK KEY OBSERVATIONS BECAUSE THERE HAS NOT YET BEEN A SUCCESSFUL MISSION DEDICATED TO THE STUDY THEM. HOWEVER SMALLSATS PROVIDE A NEWOPPORTUNITY TO CONDUCT FOCUSED INVESTIGATIONS TO ADDRESS HIGH PRIORITY SCIENCE OBJECTIVES THAT CANNOT BE OBTAINED FROM PRIMARY MARS MISSIONS AND THUS ARE IDEAL FOR A MISSION TO PHOBOS AND DEIMOS.IN THE PROPOSED CONCEPT STUDY WE WILL EVALUATE THE FEASIBILITY OF A LOW-COST CUBESAT MISSION CALLED CHARIOT THAT WILL PROVIDE HIGH RESOLUTION OBSERVATIONS OF BOTH PHOBOS AND DEIMOS IN ORDER TO DISCRIMINATE AMONG THE VARIOUS PROPOSED ORIGIN MODELS PROVIDING CRUCIAL INFORMATION ABOUT THE EARLY HISTORY OF THE MARS SYSTEM. CHARIOT WILL ACQUIRE MULTISPECTRAL THERMAL-INFRARED IMAGERY AND NEAR-INFRARED POINT SPECTRA PROVIDING CRITICAL DATA SETS FOR THE DETERMINATION OF SURFACE MORPHOLOGY AND MINERALOGY. IN ADDITION THE THERMAL IMAGING SYSTEM WILL ALLOW US TO DETERMINE SURFACE PROPERTIES (THERMAL INERTIA GRAIN SIZE COHERENCE ETC.) THAT ARE CRITICAL FOREVALUATING THE RESOURCE AND EXPLORATION POTENTIAL OF THE MOONS WITH A LEVEL OF ACCURACY THAT IS NOT POSSIBLE FROM OTHER DATASETS. WE WILL ACQUIRE HIGH-RESOLUTION VISIBLE IMAGES FOR CONTEXT AND USE RADIO SCIENCE FOR GRAVITY FIELD MAPPING. THESE MEASUREMENTS WILL CONSTRAIN THE MOONS COMPOSITION AGE AND INTERNAL STRUCTURE AND WILL PROVIDE THE BASIS FOR DETERMINING THEIR ORIGIN AND EVOLUTION. THE CHARIOT MISSION DIRECTLY ADDRESSES NASA STRATEGIC KNOWLEDGE GAPS RELATED TO PHOBOS AND DEIMOS SURFACE COMPOSITION REGOLITH PROPERTIES GRAVITATIONAL FIELDS AND RESOURCE POTENTIAL.THE BASELINE DESIGN FOR THE CHARIOT MISSION INCLUDES A 3-AXIS STABILIZED 12U CUBESAT WITH SOLAR PANELS AND ELECTRIC PROPULSION FOR MANEUVERING. CHARIOT WILL USE AEROCAPTURE TO INSERT INTO AN EQUATORIAL MARS ORBIT REPRESENTING THE FIRST DEMONSTRATION OF THIS CRITICAL TECHNOLOGY IN NASAS HUMAN EXPLORATION ROADMAP. THE VEHICLE WILL REACH MARS WITH THE ASSISTANCE OF A CRUISE STAGE THAT PROVIDESPOWER PROPULSION TELECOMMUNICATIONS AND ATTITUDE CONTROL DURING THE EARTH-TO-MARS TRANSFER. FROM THE INTERPLANETARY TRAJECTORY THE SPACECRAFT WILL DIRECTLY ENTER THE MARS ATMOSPHERE AND AEROCAPTURE INTO ORBIT. SUBSEQUENTLY THE ORBIT IS CIRCULARIZED TO MATCH THE PHOBOS ORBIT RADIUS AND THE CHARIOT CUBESAT IS DEPLOYED FROM THE AEROCAPTURE VEHICLE. FOLLOWING DEPLOYMENT CHARIOT WILL COMMUNICATE EXCLUSIVELY THROUGH UHF CROSSLINK TO EXISTING MARS ORBITERS FOR RELAY. USING ITS LOW-THRUST SYSTEM THE CUBESAT WILLMANEUVER INTO A RELATIVE ORBIT ABOUT PHOBOS FOR A 60-DAY SCIENCE MAPPING MISSION. UPON COMPLETION OF PHOBOS SCIENCE OBJECTIVES CHARIOT WILL TRANSFER TO A DEIMOS CROSSING ORBIT ALLOWING DOZENS OF CLOSE FLYBYS FOR DEIMOS SCIENCE CHARACTERIZATION.THE 6-MONTH CHARIOT MISSION CONCEPT STUDY WILL RESULT IN A FULL DESIGN FOR THE SCIENCE INSTRUMENTS MISSION DESIGN AND FLIGHT SYSTEM. WE WILL DEVELOP TECHNICAL RESOURCE BUDGETS (MASS POWER THERMAL COMMUNICATIONS PROPELLANT AND DATA RETURN) TO DEMONSTRATE FEASIBILITY. WE ALSO WILL IDENTIFY RISKS ASSOCIATED WITH DEVELOPMENT AND OPERATIONS ESTABLISH A PLAN FOR MATURATION OF TECHNOLOGIES ANDDEVELOP A GRASS-ROOTS COST ESTIMATE WITH THE ASSISTANCE OF JPL TEAM XC.