Comet nucleus tour

Summary CONTOUR, a Discovery-class flyby mission of three comets (Encke, d’Arrest, Tempel 1) provides the next step in comet exploration and is a useful precursor to more complex endeavors. The small, focused payload of three instruments (imager, dust analyzer/counter, mass spectrometer) will provide unique data on the composition of near-nucleus gas and dust, as well as on the global characteristics of the nuclei of three diverse comets. Most importantly, CONTOUR will provide the 10 m resolution (or better) imaging still needed to elucidate fundamental nucleus surface processes. A unique aspect of CONTOUR is the possibility of returning to Encke during an extended mission, for a second look after an interval of 10 years!