Dr. Swindle has spent most of his career using measurements of the noble gases in extraterrestrial materials lunar samples and meteorites) to study the evolution of the solar system. Past research projects have included performing Ar-40/Ar-39 dating of shocked lunar samples and meteorites, to study the timing of impacts in the inner Solar system; using I-129, and its decay product Xe-129, to study the timing of the formation of the earliest solids in the solar nebula; and working on developing techniques to use instruments on spacecraft to measure ages of planetary surfaces in situ. He is also active in working to develonew mission concepts.