Only five spacecraft have escaped the Sun's gravity field to travel to the outer solar system toward interstellar space: Pioneer 10 and 11, Voyagers 1 and 2, and New Horizons. Any Interstellar Probe spacecraft must be autonomous, compact and lightweight, and lean on power –yet robust enough to gather data and communicate with operators on Earth. Relying on heritage, the team is using the New Horizons spacecraft as its baseline design, with incremental improvements as needed. As with the Pioneers, Voyagers and New Horizons, the baseline power source is a radioisotope thermoelectric generator, which provides reliable power over long mission lifetimes and great distances from the Sun.
All of the instrument technologies needed to achieve an interstellar mission's science goals exist today. Given the delicate balance between asymptotic speed and mass, the study leads are seeking solutions that combine certain instrumentation to save mass, power and data rates.
A payload that addresses all science goals notionally consists of: