A Small Interstellar Probe to the Heliospheric Boundary and Interstellar Space

The Small Interstellar Probe m1ss1on would be designed to cross the solar wind termination shock and the heliopause, and make a significant penetration into nearby interstellar space. The principal scientific objectives of this mission would be to explore the structure of the heliosphere, to investigate its interaction with the interstellar medium, and to explore the nature of the interstellar medium itself. These studies would be carried out by a ~200 kg spacecraft carrying a scientific payload designed to make comprehensive, in situ measurements of both heliospheric and interstellar plasma, fields, energetic particles, gas, and dust. New trajectory calculations indicate significantly improved performance over earlier studies with larger spacecraft, including spacecraft velocities ranging from -6 to -14 AU/yr., depending on trajectory and launch vehicle