Abstract: The Comet Astrobiology Exploration Sample Return (CAESAR) mission is one of two finalists selected by NASA for Phase A study in the New Frontiers program. CAESAR will acquire a minimum of 80 grams of material from the surface of comet 67P/Churuyumov-Gerasimenko and return it to Earth for laboratory analysis. CAESAR preserves much of the science of a cryogenic sample return by retaining volatiles in a dedicated reservoir securely separated from the solid sample. Comet 67P was selected based on…