Innovative Interstellar Explorer

A robotic space probe to travel beyond the heliopause has for almost three decades been referred to as an "interstellar precursor mission." Such a probe would answer fundamental questions about environment of near interstellar space, including the local interstellar magnetic field and low-energy cosmic rays which can be measured in no other way. In addition, the interaction structure between the heliosphere and the very local interstellar medium can only be fully understood by passing a space probe through this region of space. We describe such a probe that can be built and launched within the next decade. By using existing launch vehicles, a Jupiter gravity assist, and an ion propulsion system powered by radioisotope power sources, such a mission can reach 200 AU within 30 years of launch and continue onward at a speed over twice that of the twin Voyager spacecraft.