The program of the International Halley Watch (IHW) is analyzed stressing that proper planning and coordination will serve to maximize the scientific opportunities presented by the comet's passage. The Halley Watch comprises four parts: deep space observations, earth orbital observations, nonorbital flight techniques, and earth-based observation. The current status of each of these activities is
... [Show full abstract] examined presenting observing conditions of the comet in 1986 for observers at various latitudes. Design characteristics for potential Halley Comet missions (deep space) are also given, as are sample payloads for comet observations (earth orbital) and various international missions programs.