The need for improved heat pipe fluids

Low mass high performance radiators and thermal management systems for advanced space systems are discussed. The key to these new improved thermal systems are high performance heat pipes. One aspect in achieving low mass/high performance heat pipes requires working fluids compatible with low mass materials of construction, such as aluminum, magnesium, beryllium and titanium. The application of heat pipe systems in manned spacecraft also requires the use of low or nontoxic working fluids. The development of new or improved heat pipe fluid/vessel combinations for advanced space systems should be carried out. Two approaches worthy of investigation are: the synthesis of new high performance fluids compatible with appropriate envelope materials and the development of integral impervious coatings and/or passivation to prevent the reaction of currently acceptable working fluids with the envelope.