Development of Lithium Chloride Absorber Radiator for Flight Demonstration

Abstract

Water conservation is an essential requirement for future exploration space suits. Lithium Chloride Absorber Radiator (LCAR) technology has been developed to meet this requirement by rejecting heat without venting water from a Spacesuit Evaporator Absorber Radiator (SEAR) subsystem. Prototype LCARs have been developed and optimized through numerous thermal vacuum tests that simulate operation in space. An actual flight demonstration is a key next step needed to advance the technology readiness level of the LCAR and make it available for future exploration missions. This paper describes on-going work to enable a flight test of an LCAR as part of a subscale SEAR system that uses a space station EMU as a test bed. The twin goals of this program are to develop a prototype LCAR design that can integrate with an EMU using existing flight-qualified hardware, and to develop and demonstrate a regeneration system that is suitable for use on the space station. Significant advances in LCAR technology include: (1) an optimized design of the absorber bed enables heat rejection at higher temperature and higher rates than prior LCAR designs; (2) measurement of improved heat rejection performance of the optimized LCAR panel through several absorption/regeneration cycles; (3) demonstration of a suitable coolant/refrigerant for use in the SEAR system; (4) demonstration that the prototype panel survives impact loads required for operation on the space station without compromising containment of LiCl / water solution; and (5) demonstration that the LCAR’s thermal performance is essentially unaffected after suffering a design-basis impact.