NASA seeks new thermal control technology for EVA suits on Mars. The system must be closed-loop and non-venting, have negligible impact on the Martian environment, and be capable of operating under Mars surface conditions. We propose to develop a space evaporator/absorber/radiator (SEAR) system with innovative features that will enable operation on Mars. The system uses a regenerable water absorption cooling system that rejects heat entirely by radiation. The key innovation needed for operation on Mars is an enhanced absorption process that enables thermal radiation at increased temperatures. In Phase I we will prove the feasibility of our approach through thermal/fluid/mechanical analysis and assessment of design trade-offs, proof-of-concept experiments, and design of a prototype SEAR for Mars. In Phase II we will build a prototype system and demonstrate its operation under conditions that simulate the Martian surface.