HIGH CAPACITY HEAT PIPE RADIATOR

THE HEAT REJECTION REQUIREMENTS OF FUTURE SPACE SYSTEMS ARE PROJECTED TO INCREASE BY AN ORDER OF MAGNITUDE OVER THE COMMING DECADES, TO MEET THE NEEDS OF MANNED PLANETARY MISSIONS AND BASES. THE SPACE STATION FREEDOM ALONE WILL REQUIRE 75 KW OF HEAT REJECTION AT ASSEMBLY COMPLETE (AC) AND THREE TO FOUR TIMES THAT CAPACITY IN THE GROWTH PHASE. THE SPACE CONSTRUCTABLE RADIATORS (SCRS) REPRESENT THE MAJOR WEIGHT COMPONENT IN THE THERMAL-MANAGEMENT SYSTEM, CONTRIBUTING ABOUT 40 KG/KW OF HEAT-REJECTION CAPACITY. THE SCRS ALSO REPRESENT THE LARGEST COMPONENTS, WITH A STOWED VOLUME OF 0.16 M (3)/KW. USING PRESENT TECHNOLOGY, THE GROWTH PHASE OF THE SPACE STATION FREEDOM WILL REQUIRE TRANSPORTATION TO SPACE OF 4,000 TO 9,000 KILOGRAMS OF RADIATOR PANELS AT A COST OF ABOUT $40 TO $90 MILLION. THIS PROJECT ADDRESSES THE DEVELOPMENT OF A NOVEL HIGH-CAPACITY, HEAT-PIPE RADIATOR THAT HAS THE POTENTIAL TO REDUCE THE RADIATOR WEIGHT BY A FACTOR OF 6 AND THE STOWED VOLUME BY A FACTOR OF 10. THE PROPOSED RADIATOR WOULD HAVE A SPECIFIC MASS OF ABOUT 0.7 KG/M(2), WHICH TRANSLATES TO ABOUT 6 KG/KW FOR HEAT REJECTION AT ROOM TEMPERATURE IN NEAR-EARTH ORBIT. THE RADIATOR HEAT PIPE IS ALSO INHERENTLY RESISTANT TO DEPRIMING, AND ITS EVAPORATOR WOULD HAVE A SIGNIFICANTLY HIGHER HEAT-FLUX CAPABILITY THAN PRESENT DESIGNS. IN PHASE I, THE FEASIBILITY OF THE CONCEPT WILL BE DEMONSTRATED BY DESIGNING THE KEY ELEMENTS OF THE RADIATOR AND PERFORMING SOME PROOF-OF-CONCEPT TESTS. THE HEAT REJECTION REQUIREMENTS OF FUTURE SPACE SYSTEMS ARE PROJECTED TO INCREASE BY AN ORDER OF MAGNITUDE OVER THE COMMING DECADES, TO MEET THE NEEDS OF MANNED PLANETARY MISSIONS AND BASES. THE SPACE STATION FREEDOM ALONE WILL REQUIRE 75 KW OF HEAT REJECTION AT ASSEMBLY COMPLETE (AC) AND THREE TO FOUR TIMES THAT CAPACITY IN THE GROWTH PHASE. THE SPACE CONSTRUCTABLE RADIATORS (SCRS) REPRESENT THE MAJOR WEIGHT COMPONENT IN THE THERMAL-MANAGEMENT SYSTEM, CONTRIBUTING ABOUT 40 KG/KW OF HEAT-REJECTION CAPACITY. THE SCRS ALSO REPRESENT THE LARGEST COMPONENTS, WITH A STOWED VOLUME OF 0.16 M (3)/KW. USING PRESENT TECHNOLOGY, THE GROWTH PHASE OF THE SPACE STATION FREEDOM WILL REQUIRE TRANSPORTATION TO SPACE OF 4,000 TO 9,000 KILOGRAMS OF RADIATOR PANELS AT A COST OF ABOUT $40 TO $90 MILLION. THIS PROJECT ADDRESSES THE DEVELOPMENT OF A NOVEL HIGH-CAPACITY, HEAT-PIPE RADIATOR THAT HAS THE POTENTIAL TO REDUCE THE RADIATOR WEIGHT BY A FACTOR OF 6 AND THE STOWED VOLUME BY A FACTOR OF 10. THE PROPOSED RADIATOR WOULD HAVE A SPECIFIC MASS OF ABOUT 0.7 KG/M(2), WHICH TRANSLATES TO ABOUT 6 KG/KW FOR HEAT REJECTION AT ROOM TEMPERATURE IN NEAR-EARTH ORBIT. THE RADIATOR HEAT PIPE IS ALSO INHERENTLY RESISTANT TO DEPRIMING, AND ITS EVAPORATOR WOULD HAVE A SIGNIFICANTLY HIGHER HEAT-FLUX CAPABILITY THAN PRESENT DESIGNS. IN PHASE I, THE FEASIBILITY OF THE CONCEPT WILL BE DEMONSTRATED BY DESIGNING THE KEY ELEMENTS OF THE RADIATOR AND PERFORMING SOME PROOF-OF-CONCEPT TESTS.