Warm Gas Ion Thruster

I would like to propose a warm gas ion thruster design to be used for the first stage of a rocket. Ion thrusters have high specific impulse but very low thrust. Therefore, they are mainly used for satellite navigation only. I thought about increasing the thrust by the use of warm gases and the atmosphere as the electric source; compared to cold gas and solar panel electric source used on other ion thrusters.

The warm gas ion thruster would be filled with a gas in liquid form. Initially, I thought about using liquid nitrogen due to its low cost and comparably low ionization energy. The rocket shell will be made of aluminum with carbon nanotube fiber mash to improve its strength. The idea is to electrically charge the liquid nitrogen as the rocket travels at high speeds in the air. The aluminum casing is the ideal material for that. It is a very good conductor of electric and heat. As the rocket travels faster and faster within the atmosphere it would build up more charge on it and heat up due to drag. Which are then efficiently transferred to the liquid nitrogen inside. High aspect ratio of the rocket coupled with the very thin fins inside and outside the shell increase the surface area for charge and heat accumulation.

The heated liquid nitrogen would be transferred to an evaporation chamber at the bottom of the rocket. Where it builds up pressure before exiting from the oppositely charged electret nozzle. Electrets are materials that keep their charge like permanent magnets keep their magnetism. The electret nozzle section will be thermally and electrically isolated from the rest of the rocket to preserve its charge. High voltage difference would further accelerate the exhaust gas to increase the thrust.

The warm gas ion thruster would be strapped together to achieve higher total thrust like the solid boosters attached to a liquid propulsion rocket. They would be very cheap and simple. Therefore, they don’t need to be reused like the very expensive and complex liquid rockets. The flight trajectory of the rocket should be optimized to improve the thrust efficiency. This design would only work at lower altitudes. Just before their launch, the ion thrusters would be heated and electrically charged by induction. Once the required levels are reached, the evaporation chamber would be opened to generate thrust for liftoff.