AUTOMATIC HOLOGRAPHIC CONTROLLED REFLECTIVITY/EMISSIVITY OF SPACECRAFT AND TERRESTRIAL VEHICLES

THE ABILITY TO CONTINUOUSLY CHANGE THE THERMAL REFLECTIVITY/EMISSIVITY OF EXTERNAL SPACECRAFT SURFACES AUTOMATICALLY THROUGH INTENSITY-INDUCED REFRACTIVE INDEX CHANGES IN A NONLINEAR OPTICAL LIQUID WITHIN A HOLOGRAPHIC FILM WITH NO MOVING PARTS WOULD HAVE CONSIDERABLE PERFORMANCE, RELIABILITY AND COST IMPACT ON FUTURE DOD, NASA AND COMMERCIAL SPACECRAFT AND TERRESTRIAL VEHICLES. HAVING THE ENTIRE EXTERNAL SPACECRAFT OR VEHICLE SURFACE PART OF AN ACTIVE THERMAL MANAGEMENT SYSTEM WILL ENABLE FAR MORE PRECISE PLATFORMS FOR THERMAL SENSITIVE SYSTEMS AS WELL AS GIVING THESE SYSTEMS CAMELEON ABILITY TO CHANGE THEIR THERMAL SIGNATURE WHEN INTERROGATED. AUTOMATIC THERMAL MANAGEMENT ON THE VEHICLE SKIN WILL REDUCE THE NEED (COST/WEIGHT) FOR INTERNAL HVAC SYSTEMS AND WILL IMPROVE THE ENVIRONMENT (RELIABILITY/SERVICE LIFE) FOR ELECTRONIC SYSTEMS. THE PROPOSED PHASE I PROGRAM WILL DESIGN, FABRICATE AND DEMONSTRATE A BROADBAND VARIABLE HOLOGRAM IN A RUGGED, THIN POLYMER FILM THAT WILL CONTROL SURFACE REFLECTIVITY/EMISSIVITY OVER A WIDE DYNAMIC RANGE. OUR GOAL IS TO ACHIEVE 99% REFLECTIVITY WITH THE HOLOGRAM TURNED FULL-ON, A DYNAMIC RANGE OF AT LEAST 80% WITH A TIME CONSTANT OF AT LEAST ONE SECOND TO REACH THE 90% POINT IN EITHER DIRECTION. IN PHASE II WE WILL ADDRESS THE PRODUCIBILITY ISSUES OF THE TUNABLE HOLOGRAPHIC FILM WITH OUR COMMERCIAL PARTNER, POLAROID. WE WILL FABRICATE A MODEL VEHICLE WITH A CONTROLLABLE REFLECTIVITY EMISSIVITY EXTERNAL SKIN AND TEST THIS MODEL IN A SOLAR SIMULATION TEST CHAMBER WITH THE HELP OF OUR AEROSPACE PARTNER, LOCKHEED. ANTICIPATED BENEFITS/POTENTIAL APPLICATIONS - IN ADDITION TO THE POTENTIAL OF REVOLUTIONIZING THE THERMAL MANAGEMENT DESIGN OF SPACECRAFT, EARTHBOUND VEHICLES AND HABITATS, TUNABLE HOLOGRAMS WILL HAVE MANY APPLICATIONS IN EMERGING LASER BASED TECHNOLOGIES INCLUDING OPTICAL SWITCHES, BEAM DIVIDERS, OPTICAL NEURAL NETWORKS, LASER PROTECTION AND A VARIETY OF OPTICAL COMPUTING SYSTEMS. THE AUTOMOTIVE AND ARCHITECTURAL APPLICATIONS ALONE MAKE TUNABLE HOLOGRAMS AN EXCITING COMMERCIAL OPPORTUNITY.