SINCE ITS LAUNCH IN 2002 AQUA HAS DEMONSTRATED A VERY HIGH LEVEL OF PRECISION IN THE PRIMARY LONG-TERM MEASUREMENTS MADE BY THE MISSION. THESE HIGHLY CALIBRATED CLIMATE QUALITY MEASUREMENTS OF RADIANCE REFLECTANCE AND BACKSCATTER HAVE BEEN USED TO CROSS-CALIBRATE PAST AND PRESENT SENSORS LAUNCHED BY NASA AS WELL AS A VARIETY OF SENSORS LAUNCHED FROM OTHER AGENCIES AND THE INTERNATIONAL COMMUNITY. THOUSANDS OF SCIENTISTS AND OPERATIONAL USERS FROM AROUND THE WORLD ARE MAKING USE OF THE AQUA DATA TO ADDRESS NASA'S SIX INTERDISCIPLINARY EARTH SCIENCE FOCUS AREAS: ATMOSPHERIC COMPOSITION WEATHER CARBON CYCLE AND ECOSYSTEMS WATER AND ENERGY CYCLE CLIMATE VARIABILITY AND CHANGE AND EARTH SURFACE AND INTERIOR. THE AQUA TIME SERIES OF OBSERVATIONS BECOMES INCREASINGLY VALUABLE AS THE LENGTH OF THE DATASET IS EXTENDED AND EPISODIC FLUCTUATIONS CAN BE DIFFERENTIATED FROM SECULAR TRENDS TO BETTER ASSESS ENVIRONMENTAL PROCESSES. SUCH LONG-TERM DATA RECORDS CAN BE USED TO ADDRESS A VARIETY OF INTERDISCIPLINARY SCIENCE TOPICS INCLUDING: ( 1) UNDERSTANDING HOW CHANGES IN EARTH'S OCEANIC AND TERRESTRIAL ECOSYSTEM STRUCTURE AND BIODIVERSITY INFORM IMPROVED MANAGEMENT PRACTICES; (2) QUANTIFYING THE FEEDBACKS BETWEEN CLOUDS AEROSOLS AND CLIMATE CHANGE; (3) ASSESSING MECHANISMS FOR CHANGING POLAR TEMPERATURES AND SEA ICE OVERTIME; (4) IMPROVING FORECASTING AND MITIGATION OF NATURAL DISASTERS AND EXTREME WEATHER; AND (5) EVALUATING THE GEOGRAPHICAL DISTRIBUTION OF TERRESTRIAL AND AQUATIC HABITATS. THE AQUA SPACECRAFT IS STILL HIGHLY CAPABLE AFTER 15 YEARS AND FOUR OF ITS INSTRUMENTS (ATMOSPHERIC INFRARED SOUNDER AIRS ADVANCED MICROWAVE SOUNDING UNIT AMSU CLOUDS AND THE EARTH'S RADIANT ENERGY SYSTEM CERES AND MODERATE RESOLUTION IMAGING SPECTRORADIOMETER MODIS CONTINUE TO COLLECT VALUABLE DATA ABOUT THE ATMOSPHERE OCEANS LAND AND ICE. AS DEMONSTRATED BY AQUA'S HIGH QUALITY CLIMATE DATA RECORDS THE CONTINUITY OF THIS TIME SERIES IS CRITICAL FOR THE SCIENTIFIC COMMUNITY GOVERNMENTAL AGENCIES AND THE INTERNATIONAL OPERATIONAL USER COMMUNITY. THEREFORE THE SUBCOMMITTEE RECOMMENDED THAT THE AQUA MISSION CONTINUE AS CURRENTLY BASELINED. A FURTHER RECOMMENDATION CONCERNS THE MODIS SENSOR. THE OCEAN BIOLOGY PROCESSING GROUP OBPG HAS OBSERVED SOME DEGRADATION OF CHANNELS IN THE MODIS SHORTWAVE VISIBLE BANDS. FOR THE FUTURE THIS REQUIRES EXTRA CORRECTIONS FOR OCEAN APPLICATIONS. AT PRESENT THE IMPACT ON MOST OTHER AQUA DATA PRODUCTS IS CONSIDERED NEGLIGIBLE BUT THE ISSUE SHOULD BE COMMUNICATED MORE PROMINENTLY TO THE BROAD COMMUNITY OF EXTERNAL SCIENCE USERS. MOREOVER BECAUSE OF THE DIFFERENCES BETWEEN THE CALIBRATION APPROACHES OF THE MODIS CHARACTERIZATION SUPPORT TEAM MCST AND THE OBPG THE SUBCOMMITTEE RECOMMENDED THAT THE OBPG BE INCLUDED IN FUTURE SENIOR REVIEWS TO BE ABLE TO DIRECTLY ADDRESS QUESTIONS AND UNCERTAINTIES ABOUT THE MISSION. TWENTY-SIX THREE-PAGE PROPOSALS FOR SUPPORT OF EXISTING SCIENCE DATA PRODUCTS AND ALGORITHM MAINTENANCE WERE SUBMITTED IN CONJUNCTION WITH THE AQUA PROPOSAL. THIS WORK HAS TRADITIONALLY BEEN COMPETED IN RESEARCH OPPORTUNITIES IN EARTH AND SPACE SCIENCE ROSES PROGRAM ELEMENTS BUT EVALUATIONS ARE NOW BEING TRANSFERRED TO THE ESD SENIOR REVIEW. THESE ALGORITHM PROPOSALS FOCUS ON CRITICAL ACTIVITIES ESSENTIAL TO THE MAINTENANCE OF DATA PRODUCT QUALITY AND A SEAMLESS TIME SERIES. EXTENDING THIS WORK WILL BE ESSENTIAL TO THE CONTINUED SUCCESS OF THE AQUA MISSION. THE SUBCOMMITTEE RECOMMENDED CONTINUED SUPPORT OF THESE ALGORITHMS AND STANDARD DATA PRODUCTS FOR THE NEXT THREE YEARS AT ROUGHLY THE LEVEL OF FUNDING REQUESTED. I HAVE USED THE SUBCOMMITTEE'S ASSESSMENT IN FORMULATING THE MISSION PROGRAMMATIC DIRECTIONS FOR THE FY2018-2023 PERIOD. THESE NEW GUIDELINES TOGETHER WITH THE SCOPE OF ACTIVITIES DEFINED IN THIS LETTER CONSTITUTE THE NEW PROJECT REQUIREMENTS FOR THE EXTENDED MISSION. YOUR RESPONSE TO THIS DIRECTION SHOULD BE IN THE FORM OF A LETTER THAT INCLUDES THE AQUA PROJECT'S RESPONSE TO TH