Future Missions to the Giant Planets that can Advance Atmospheric Science Objectives

Other papers in this special issue have discussed the diversity of planetary atmospheres andsome of the key science questions for giant planet atmospheres to be addressed in thefuture. There are crucial measurements that can only be made by orbiters of giant planetsand probes dropped into their atmospheres. To help the community be more effectivedevelopers of missions and users of data products, we summarize how NASA and ESAcategorize their planetary space missions, and the restrictions and requirements placed oneach category. We then discuss the atmospheric goals to be addressed by currentlyapproved giant-planet missions as well as missions likely to be considered in the next fewyears, such as a joint NASA/ESA Ice Giant orbiter with atmospheric probe. Our focus is oninterplanetary spacecraft, but we acknowledge the crucial role to be played by ground-basedand near-Earth telescopes, as well as theoretical and laboratory work.