Rapid Manned Mars Mission with a Propagating Magnetic Wave Plasma Accelerator

Summary

This document proposes an advanced propulsion concept for deep space exploration using a travelling magnetic wave accelerator to accelerate a magnetically self-confined plasmoid (Field Reversed Configuration or FRC). The technology promises dramatic increases in specific impulse (up to 30,000 s) and high thrust power with exhaust velocities reaching up to 0.01c for rapid manned missions to Mars.

Proposal Summary

Dr. John Slough MSNW “Rapid Manned Mars Mission with a Propagating Magnetic Wave Plasma Accelerator”

For man to venture forth into the solar system, a radically different propulsion system must be envisioned to make these deep space missions possible. The requirements for deep space exploration are two-fold. First, there must be a power source that employs a fuel with a very high specific energy. This fuel must also be available in sufficient quantity for long missions. It is recognized that nuclear fusion is one known source that can satisfy this requirement. Second, there must be an efficient method for converting this energy into the thrust and Isp necessary for a fast mission. It is proposed here to solve this second problem. This is accomplished by employing a travelling magnetic wave accelerator to accelerate a magnetically self-confined plasmoid, commonly referred to as a Field Reversed Configuration (FRC). Since the FRC is magnetically isolated from the accelerator, there is no contact between the propellant (RFC) and the accelerator. The transfer of momentum to the FRC occurs through an electromagnetic interaction with the magnetic wave so that the exhaust velocity could, at least theoretically, approach the speed of light. In previous experiments carried out by the proposers, FRCs of near milligram mass accelerated to velocities of 2x10^5 m/s in a single pulse. A novel inductive magnetized plasma source now being developed at MSNW will make it possible to produce FRCs at a very high pulse repetition rate. Using this plasma source, the acceleration scheme proposed here will allow for orders of magnitude increases in Isp over conventional electric propulsion with efficiencies that approach unity. The physical requirements for the accelerator are quite modest. The magnetic fields employed are ~0.3 T and superconducting coils are not required. The concept appears simple enough that a proof of principle experiment could be initiated that would produce plasma mass exhaust velocities approaching 0.01c.

Performance Parameters and System Diagram

Diagram: Magnetized Plasma Toroid within a Propagating Magnetic Field (from 2D MHD calculation) inside a Helical Transmission Coil.

Performance Parameters:

• System length: First Stage = 5 m | Final = 25 m
• Plasma mass mp: First Stage = 0.2 mg D2 | Final = (same)
• Final plasma velocity: First Stage = 3x10^5 m/sec | Final = (Isp = 30,000 s) 1x10^6 m/s
• Acceleration (Force): First Stage = 2x10^10 m/s (4 kN) | Final = (same)
• Thrust Power (1 kHz rep): First Stage = 9 MW | Final = 100 MW