The Quest for Interstellar Exploration

Abstract. NASA strategic planning includes the objective for a set of missions that would begin exploration beyond our solar system. These missions would determine the nature of the interface between our solar system and the local interstellar medium, as well as directly sample the properties of the interstellar medium as an initial step in exploring the nearby Galaxy. Preliminary planning envisions four missions making up this initial quest for exploration. Each of the mission concepts is described in terms of science objectives, mission characteristics, and technology needs. The four missions are: 1) Interstellar Probe (reaching 200 AU in < 15 years via solar sail to explore the heliospheric boundaries and the interstellar medium); 2) Heliosphere Imager & Galactic Gas Sampler (delivery to a low inclination, 1 by 4 A U ecliptic orbit to establish the 3-D structure of the heliosphere and boundaries and sample Galactic material injected into the heliosphere); 3) Outer Heliosphere Radio Imager (16 subsatellites with mother spacecraft delivered to 20 to 30 A U via solar sail to radio-image the boundaries of the heliosphere); and 4) Interstellar Trailblazer (reach 2000 AU in- 30 years via advanced solar sail to explore the local interstellar cloud). Technology needs for these missions include solar sail propulsion, advanced instrumentation, autonomous spacecraft operations, advanced power, advanced telecommuni-cation, and long life systems