<p>Space exploration has been long constrained by the efficiency and capability of modern chemical rocket. Propellant-less propulsion has been proposed as a solution to expand the boundary of space exploration. In this paper, we examine the possibilities of a propellantless propulsion scheme through the interaction between the spacecraft and ambient plasma. The spacecraft is charged to high electric potential by constantly shooting electrons away. The high voltage spacecraft will deplete the surrounding electrons, thus interact with a wide range of the background plasma (solar wind) and thus effectively extract momentum from the plasma. By taking advantage of the exploitable ambient plasma, a spacecraft can reach very high speed, thus considerably reducing the travel time. The scheme is also applicable for braking, which is helpful in the exploration of inner planets like Venus and Mercury, and the stopping at the destination planets or stars.</p>