VASIMR (Variable Specific Impulse Magnetoplasma Rocket) is an electrodeless electric-propulsion concept: a helicon antenna ionizes argon gas into cold plasma, a second RF stage tuned to the ion cyclotron resonance frequency heats the ions' gyration around the magnetic field, and a magnetic nozzle downstream converts that perpendicular energy into directed thrust as the field lines diverge and the adiabatic invariant μ = E⊥/B forces the energy axial. This simulator lets you split a fixed RF power budget between ionization and heating, adjust propellant flow and nozzle field strength, and watch the plasma stream through all three stages in 3D while thrust, specific impulse, exhaust velocity and jet efficiency update live from the underlying energy-balance equations — the same thrust/Isp trade a real magnetoplasma rocket makes in flight.