The science goals of heliospheric and planetary missions continue to require longer mission durations. Meeting the science goals being discussed for the Interstellar Probe mission will require the spacecraft to operate for 50 or more years. The mission will require not only a spacecraft to operate for this long duration but also a team of scientists, engineers, and managers and an infrastructure that can support the mission and science objectives. In this paper, we review past missions that have met these challenges – Voyager, Cassini, and New Horizons – and draw upon the sociology of science and technology – tacit knowledge, repair work, and management continuity – to reveal what lessons can be learned to provide strategies for this next generation of mission exemplified by the Interstellar Probe concept. We provide recommendations for making mission longevity part of the mission planning process with an eye to the human dimension.