THE ACTIVE THERMAL ARCHITECTURE FOR CRYOGENIC OPTICAL INSTRUMENTS (ATACOI) WILL ADVANCE THE TECHNOLOGY READINESS LEVEL OF IR OPTICAL INSTRUMENTS THERMAL SUPPORT SYSTEMS TARGETING 6U CUBESAT FORM FACTORS AND ABOVE. SPECIFICALLY THE DEVELOPMENT OF A DEPLOYABLE SOLAR TRACKING RADIATOR A ROTATIONALLY FLEXIBLE FLUID UNION HINGE AND MECHANICAL VIBRATION AND THERMAL ISOLATION OF ELECTRO-OPTIC DETECTORS IN THE RANGE OF 60-100 K. SUCH A UNIQUE THERMAL MANAGEMENT SYSTEM WILL ENABLE A NEW GENERATION OF CUBESAT BASED MWIR AND LWIR EXPLORATION MISSIONS IN THE FIELDS OF HELIOPHYSICS AND EARTH SCIENCE OTHERWISE THOUGHT IMPOSSIBLE IN SUCH SMALL SATELLITES. THE ATACOI PROJECT WILL TARGET 6U AND 12U FORM FACTORS AND WILL CONSIST OF A FIRST STAGE MECHANICALLY PUMPED FLUID LOOP AS THE PRIMARY THERMAL CONTROL SYSTEM. A MINIATURE CRYOCOOLER WILL MOUNT TO A HEAT EXCHANGER (HX) WITHIN THE MECHANICALLY PUMPED FLUID LOOP AND FORM THE SECOND STAGE. THE PUMPED FLUID LOOP WILL CONNECT TO A ONE-TIME DEPLOYABLE SOLAR TRACKING RADIATOR THROUGH A SINGLE AXIS ROTATIONALLY FLEXIBLE FLUID UNION. INTEGRATION OF THE PUMPED FLUID LOOPS CONFORMAL COOLANT CHANNELS WITH THE CUBESATS INSTRUMENTS SYSTEMS CHASSIS AND RADIATOR WILL BE ENABLED VIA ULTRASONIC ADDITIVE MANUFACTURING TECHNIQUES. THE SYSTEM WILL ALSO BE ISOLATED FROM EXPORTED VIBRATION AND PARASITIC THERMAL LOADS. THE ATACOI TEAM INVOLVES EXPERTS AT UTAH STATE UNIVERSITIES CENTER FOR SPACE ENGINEERING IN SPACECRAFT SYSTEMS ELECTRO-OPTICAL INSTRUMENTATION EXPORTED VIBRATION MANAGEMENT AND THERMAL CONTROL COUPLED WITH JPLS EXPERTISE IN MECHANICAL PUMPED FLUID LOOP THERMAL CONTROL SYSTEMS ADDITIVE MANUFACTURING CRYOCOOLER TECHNOLOGY AND INTEGRATION AND SPACE SYSTEM DESIGN. THIS COMBINED KNOWLEDGE OF HIGH PERFORMANCE THERMAL DESIGN SPACECRAFT SYSTEMS ENGINEERING AND THE FRESH INNOVATIVE PERSPECTIVE OF THE UNIVERSITY COMMUNITY WILL ALLOW THE TEAM TO DEVELOP AND INTEGRATE THESE NEW TECHNOLOGIES INTO A COMPLETE PROTO-FLIGHT THERMAL MANAGEMENT SUBSYSTEM CAPABLE OF ENABLING GROUND BREAKING NEW CUBESAT SCIENCE MISSIONS. PERIOD OF PERFORMANCE WILL BE 24 MONTHS. THE STARTING TRL OF THE ATACOI SYSTEM WILL BE BETWEEN A 3-4. RADIATOR DEPLOYMENT PANEL TRACKING FLUID COUPLING AND VIBRATIONAL ISOLATION HAVE ALL BEEN DEMONSTRATED WITHIN NASA AND THE INDUSTRY. THE MINIATURE CRYOCOOLER UAM RADIATOR AND MPFL SYSTEMS WILL ALREADY BE DEMONSTRATED IN A RELEVANT GROUND BASED TVAC SYSTEM THROUGH THE ACCS PROJECT (TRL 5) BY THE START TIME OF THIS PROJECT. STUDENTS AND RESEARCHERS AT UTAH STATE UNIVERSITY IN COLLABORATION WITH COLLEAGUES AT NASA JPL WILL COMPLETE THIS WORK.