A direct fusion drive for rocket propulsion

• The odd-parity rotating magnetic field effectively heats a small reactor to fusion temperatures.
• Field-reversed configuration devices provide high specific powers for propulsion.
• The James Webb Space Telescope can be deployed to a Sun–Earth L2 orbit in 437 days.
• On that mission, a 1 MW reactor would consume about half a kilogram of 3He and 353 kg of D.
• Compact, aneutronic fusion reactors provide a safe option for manned missions.

The Direct Fusion Drive (DFD), a compact, anuetronic fusion engine, will enable more challenging exploration missions in the solar system. The engine proposed here uses a deuterium–helium-3 reaction to produce fusion energy by employing a novel field-reversed configuration (FRC) for magnetic confinement. The FRC has a simple linear solenoid coil geometry yet generates higher plasma pressure, hence higher fusion power density, for a given magnetic field strength than other magnetic-confinement plasma devices. Waste heat generated from the plasma׳s Bremsstrahlung and synchrotron radiation is recycled to maintain the fusion temperature. The charged reaction products, augmented by additional propellant, are exhausted through a magnetic nozzle. A 1 MW DFD is presented in the context of a mission to deploy the James Webb Space Telescope (6200 kg) from GPS orbit to a Sun–Earth L2 halo orbit in 37 days using just 353 kg of propellant and about half a kilogram of 3He. The engine is designed to produce 40 N of thrust with an exhaust velocity of 56.5 km/s and has a specific power of 0.18 kW/kg.