Princeton Plasma Physics Laboratory (PPPL) physicist Fatima Ebrahimi has proposed a new type of interplanetary rocket engine that is capable of delivering people to Mars and other planets faster than existing developments. The theoretical engine is detailed in an article published in the Journal of Plasma Physics. The study is summarized in a press release at Phys.org.
The principle of the engine is based on continuous generation of plasmoids – plasma clots supported by a closed magnetic field. A similar configuration is created inside tokamaks, which are an annular channel in which a field with high magnetic helicity is created (which characterizes the twisting and cohesion of field lines). Plasmoids are created by reconnecting magnetic field lines. According to the simulation results, the exhaust speed will reach 20-500 kilometers per second.
Existing prototypes of plasma engines use not a magnetic, but an electric field, but their specific impulse remains too low, that is, a lot of fuel is required to accelerate. A flight to Mars on a rocket with a chemical engine will take a year or more, but the new engine can shorten this period by several times. Changing the strength of the magnetic field will allow you to control the thrust for a specific space mission.
According to Ibrahim, the idea for the motor came to her while working with the tokamak as part of the National Spherical Torus Experiment at (NSTX) PPPL. The installation produced plasmoids that moved at a speed of 20 kilometers per second, which could create thrust. Another similar PPPL project, the Hall Thruster, is a prototype ion thruster where fuel is accelerated by an electric field. Such engines can be used to increase the maneuverability of CubeSats nanosatellites.