Ion Thrusters Are the Future

Ion Thrusters, yes those things from Star Trek, are real and making a big splash in Spacecraft propulsion. Excite the ions in an inert gas like xenon, and wham! you're moving. Granted, you are traveling very, very slowly at first. The force exerted out the rear nozzle is about as strong as $6 in quarters resting in the palm of your hand, but in the vacuum of Space inertia allows that force to build to the limits of physics.
The nuclear powered version will provide speeds up to 200,000 mph when it's throttled up, give the pilot full throttle control and provide enough electricity for a practically limitless amount of experimentation.
Prometheus is only the beginning...