Cometary Science Working Group, Meeting, Williams Bay, Wis., June 9-11, 1971, Proceedings.The scope of cometary research is delineated in papers covering the present state of knowledge, detailed objectives of further cometary investigations, the need for ground-based observations, and the types of space missions which would be most suited in the period from 1975 to the mid-1980's. Major contributions of space missions are (1) to identify parent molecules released by the nucleus before they dissociate in the coma, (2) to measure the composition of tail constituents and the electromagnetic environment in the tail, and (3) to define the nature of the cometary nucleus. Experimental payloads and mission parameters are identified for fast flyby, slow flyby, and rendezvous missions to particular comets.