The Griffiths ISRU-Powered Plasma Hopper (IMPH)A Shear-Stabilized Electromagnetic Surface Hopper with ISRU Propellant Generation and Kelvin-Helmholtz Bounded Operation

Abstract

The Griffiths ISRU-Powered Plasma Hopper (IMPH) is a disc-shaped surface lander and hopper vehicle designed for planetary exploration on bodies where in-situ resources are accessible at or near the surface. The IMPH harvests local feedstock (CO2 from the Martian atmosphere, H2O ice from polar deposits, CH4 from Titan surface lakes), cracks it via an integrated GNMT microwave power module, generates plasma through electromagnetic confinement coils, and fires a burst-mode plasma plume downward through the electromagnetic edge to execute surface hops of 10 to 500 km range. The architecture eliminates dependence on Earth-supplied propellant: the planetary surface itself is the fuel source. The plasma drive employs shear-stabilized electromagnetic confinement addressing fundamental instability limitations in high-power plasma thrusters. Traditional systems including VASIMR, helicon thrusters, and magnetoplasmadynamic accelerators suffer from Kelvin-Helmholtz instabilities, anomalous cross-field transport, and erosion from plasma-wall interactions. The IMPH resolves these through engineered shear-layer stabilization where controlled velocity gradients create viscous dissipation exceeding instability growth rates, maintaining stable operation without active feedback control or complex magnetic field topologies. The vehicle operates in three modes. Mode A provides low-power plasma conditioning and precision landing at 10 to 50 kW, 5 to 15 N, Isp 1,500 to 2,500 s. Mode B executes primary hop ascent and descent burns at 50 to 200 kW, 20 to 60 N, Isp 2,500 to 3,500 s. Mode C enables high-performance long-range hops at 200 to 500 kW, 60 to 150 N, Isp 3,500 to 5,000 s with Kelvin-Helmholtz stability margins exceeding factors of 3 to 5 over critical thresholds. Mode transitions occur through software control of magnetic field strength, propellant flow rate, and microwave power allocation without hardware reconfiguration.