The mission concept developed by the Interstellar Probe Definition Team and JPL meets all mission requirements. To travel to >200 AU within 15 years, Interstellar Probe will rely on solar sail propulsion. For the trajectory shown, an exit velocity of ~14 AU/year is needed. This can be achieved with a 200 m radius sail with an areal density of 1 g/m² (sail material plus support structure). The total accelerated mass (spacecraft plus sail system) is ~246 kg. Following a Delta-II launch, the spacecraft uses the solar sail to maneuver in to 0.25 AU to obtain increased radiation pressure before accelerating towards the nose of the heliosphere. To avoid interference with the instruments, the sail is jettisoned at ~5 AU when the effect of the light pressure becomes negligible. The final velocity is 70 km/s, four times that of the Voyager 1 spacecraft. The required orientation of the sail relative to the Sun is indicated on the trajectory diagram.

The spacecraft is designed for a mission to 200 AU with consumables to last to 400 AU (~30 year mission). Science and engineering data are gathered at an average rate of 30 bps. The telecommunications system uses Ka band to communicate with the Deep Space Network; data is stored and dumped during 1 pass/week. The 2.7 m antenna can accommodate a downlink data rate of 350 bps at 200 AU using a 220 W transmitter. Power is provided by three next-generation advanced radioisotope power source (ARPS) units.