The Voyager Neptune/Interstellar Mission is the continuation of the NASA program of exploration of the outer solar system. The prior phases of the Voyager program included encounters with Jupiter, Saturn, and Uranus as summarized in the Journal of Geophysical Research (volume 86, pages 8121–8841, 1981; volume 88, pages 8625–9018, 1983; and volume 92, pages 14,873–15,375, 1987). Following the successes of these prior phases of the Voyager mission, a new phase was undertaken with the objectives of exploring the Neptune system and continuing the investigation of the interplanetary and interstellar media. An additional objective was to preserve the capability to extend the investigations to include a search for the heliopause. Summaries of results from the Neptune and Triton encounters are reported in the following papers.