Innovative Interstellar Explorer was a NASA "Vision Mission" study funded by NASA following a proposal under NRA-03-OSS-01 on 11 September 2003. This study has focused on the elusive quest to reach and measure the interstellar medium, the "undiscovered country" outside of the influence of the nearest star, the Sun.[1] It proposes to use a radioisotope thermal generator with ion thrusters.[1] The project is a study of a proposed interstellar precursor mission that would probe the nearby interstellar medium and measure the properties of magnetic fields and cosmic rays and their effects on a craft leaving the Solar System.[2]
Several routes are proposed, but one recommendation consists of a launch in late 2014, Jupiter flyby in early 2016, and reaching 200 AU in 2044.[1][2] It would try reach a speed of about 7.9 AU/yr by the time its xenon propellant was depleted, allowing it to reach 1000 AU after about one hundred years from launch.[1]