THIS PROPOSAL AIMS TO DEVELOP AN IMPROVED CARBON DIOXIDE ADSORBENT FOR AIR RECYCLING ABOARD SPACE VESSELS. AS NASA TRENDS TOWARD LONGER MISSIONS THE DEVELOPMENT OF NEW STRATEGIES TO ENSURE THE LONG-TERM HEALTH AND SAFETY OF CREWMEMBERS IS ESSENTIAL. CO2 REMOVAL FOR AIR PURIFICATION AND RECIRCULATION IS A CRITICAL COMPONENT OF THIS AS EVEN SLIGHTLY ELEVATED AMBIENT CO2 CONCENTRATIONS HAVE BEEN SHOWN TO CAUSE DETRIMENTAL EFFECTS ON CREWMEMBER WELL-BEING AND COGNITIVE FUNCTION OVER EXTENDED PERIODS OF TIME. THE CURRENT STATE OF THE ART TECHNOLOGY USED ON THE ISS EMPLOYED ZEOLITE 5A TO CAPTURE CO2 AND REQUIRED PRETREATMENT OF THE INLET GAS STREAM TO REMOVE ANY WATER BEFORE CONTACTING THE ZEOLITE MATERIAL. THIS TECHNOLOGY SERVED THE ISS FOR 16 YEARS AND SUPPORTED AN INCREDIBLE AMOUNT OF MEANINGFUL SPACE RESEARCH HOWEVER THERE ARE MANY IMPROVEMENTS THAT CAN BE MADE IN ORDER TO PRODUCE MORE EFFICIENT MATERIALS FOR FUTURE SPACE VESSELS. THIS ZEOLITE MATERIAL IS EXTREMELY SENSITIVE TO WATER BOTH IN HAVING A STRONG AFFINITY FOR WATER BINDING LEADING TO LOSS OF CO2 CAPACITY OVER TIME AND IN UNDERGOING STRUCTURAL DEGRADATION IN THE PRESENCE OF WATER LEADING TO DUSTING. FURTHERMORE REGENERATION OF ZEOLITE 5A REQUIRES HARSH CONDITIONS OF HIGH VACUUM AND TEMPERATURES UP TO 400 C. FINALLY DEEPER REMOVAL OF CO2 FROM THE CABIN ATMOSPHERE IS DESIRABLE AS THE PREVIOUS TARGET CONCENTRATION SET FOR THE ISS RESULTED IN ADVERSE EFFECTS TO CREWMEMBER HEALTH AND COMFORT LEADING TO FURTHER REDUCTION OF THE TARGET CONCENTRATION MOVING FORWARD. DEVELOPING AN IMPROVED CO2 ADSORBENT FOR USE IN SPACE VESSEL ENVIRONMENTAL CONTROL IS DIRECTLY IN LINE WITH TA6.1.1 SPECIFICALLY REALIZING THE TECHNOLOGY GOALS OF TA6.1.1.1. HERE NEW ADSORBENT MATERIALS WILL BE DEVELOPED TO ACHIEVE EACH OF THE ABOVE TARGETS AND IMPROVE UPON CURRENT TECHNOLOGY. THE PROPOSED MATERIALS DIAMINE-APPENDED METAL ORGANIC FRAMEWORKS (MOFS) ARE A CLASS OF SOLID ADSORBENTS THAT POSSESS DISTINCT CO2 AND H2O BINDING SITES ALLOWING FOR STABILITY AND PERFORMANCE IN HUMID CONDITIONS. THIS ALLOWS FOR THE POTENTIAL ELIMINATION OF PRE-TREATMENT BEDS FOR H2O REMOVAL WHICH WILL CUT DOWN ON UNIT SIZE AND IS PROMISING FOR THE REDUCTION OF DUSTING AND ASSOCIATED MAINTENANCE. DIAMINE-APPENDED MOFS ALSO EXHIBIT IMPROVED CAPACITIES AND LOWER REGENERATION TEMPERATURES WHICH WILL SERVE TO FURTHER DECREASE UNIT SIZE AND ALSO DECREASE ENERGY CONSUMPTION REQUIREMENTS. ADDITIONALLY THESE MATERIALS ARE HIGHLY TUNABLE WHERE SMALL CHANGES IN DIAMINE STRUCTURE PRODUCE PREDICTABLE CHANGES IN THE RESULTING CO2 ADSORPTION H2O CO-ADSORPTION AND KINETIC PROPERTIES. SEVERAL VARIANTS OF THESE MATERIALS HAVE BEEN SHOWN IN PRELIMINARY STUDIES TO ADSORB CO2 AT THE LOW CONCENTRATIONS NEEDED FOR AIR RECYCLING APPLICATIONS. THESE VARIANTS WILL BE STUDIED THROUGH EXTENSIVE PERFORMANCE TESTING IN HUMID CONDITIONS ASSESSMENT OF H2O CO-ADSORPTION AND MEASUREMENT OF CO2 CAPTURE CAPABILITY FROM SIMULATED CABIN AIR IN A BENCH-SCALE ADSORPTION COLUMN UNIT. THE OPTIMAL STRUCTURE WILL BE SUBSEQUENTLY SELECTED AND FURTHER DEVELOPED.