Nasa is currently working on a project, that could have a massive impact on the future of space travel. They are experimenting on an ion thruster, which takes up little to no energy, but also provides very little thrust in return. The solution, was to supply constant thrust until reaching the preferred speed. Instead of using a few big blasts, we use many small blasts. This way our satellites, and other space craft, can move further through space without using gravity boosting. Gravity boosting is when space craft use a planet's gravity in order to speed it up, as conventional fuel cannot get the job done. With the new ion thruster humans can travel out side our own solar system, and potentially anywhere else in the galaxy, given the time and resources. What I am suggesting is that the government funds their research, as it is highly beneficial to space travel. Thoughts?
Sounds good until you do the math. The dirty little secret about ion thrusters and other reaction rockets which throw 'stuff' out at very high velocities is that they may be propellant efficient but are energy inefficient. Its a tradeoff. Space geeks spout confusing stuff like delta V and the rocket equation to muddy the water. But fundamentally reaction rocket space travel breaks down to 2 equations. Force=mass * acceleration and kinetic energy=(1/2)*mass*(velocity squared). You can get thrust needed for a mission by shooting ions out at a very high velocity but only at the cost of quadrupling the energy needed every time you double the velocity of the ion rocket exhaust. Ion drives are great as long as solar power is plentiful, such as the inner solar system. But out in interstellar space solar energy is pretty thin. Then you have to go back to bulky atomic reactors which take a LOT of energy and propellant to move around. Disney's 1957 Mars and Beyond presented Ernst Stuhlinger's atomic powered 'parasol' ion propulsion ships but it was concluded that they were too inefficient due to the issues I mentioned. They looked beautiful though.
