Direct flight to Pluto using solar electric propulsion

High-performance spacecraft propulsion and lightweight integrated science payloads promise to enable extensive exploration of the outer solar system. Previous analysis has shown that a small, yet highly capable, spacecraft launched on a Delta II could be propelled by solar-powered ion thrusters on an Earth-gravity-assist trajectory that reaches Pluto in just 7-8 years. Whether additional development of solar electric propulsion technology could improve the power-to-mass ratio sufficiently to enable using a direct trajectory is determined, The advantages would be a slower flyby velocity at target encounter and a much reduced operating time required of the propulsion system, This approach becomes feasible with the implementation of two anticipated advances: a lightweight, foldable-blanket solar array operating at 1000 V, and thruster ion optics made with high-durability carbon-carbon composite material.