Past, Current, and Future Mission Support with Ground-Based Observations of Comets at MM/Sub-MM and Near-IR Wavelengths

Missions targeting comets afford an opportunity to sample primitive remnants of the protosolar disk at unprecedented scales. Rendezvous missions, such as Rosetta to comet 67P/Churyumov-Gerasimenko, and space platforms such as the James Webb Space Telescope, provide paradigm-challenging science with in-depth studies of individual small bodies that cannot be realized from the ground. However, extracting the full science return of these missions requires placing their results into the context of extensive ground-based work targeting the comet population at large. Furthermore, fully characterizing intrinsically variable objects such as comets requires serial observations, which may not be feasible for particular missions. Ground-based observations of comets at mm/sub-mm and near-IR wavelengths can provide this support and enhanced science and are highly complementary to multiple past, current, and future missions. We will discuss recently executed Keck/NIRSPEC and NASA-IRTF/iSHELL observations of comet 67P/Churyumov-Gerasimenko supporting Rosetta, as well as ongoing ALMA Cycle 8 observations of comet C/2017 K2 (PanSTARRS) supporting JWST, and will examine opportunities for future mission support.