Magnetohydrodynamic Analysis of Thrust Characteristics on Magneto-Plasma Sail with Plasma Magnetic Field Inflation by Low-Beta Plasma

Abstract

Magneto-Plasma Sail (MPS) is a sail space propulsion system utilizing an artificial magnetosphere, which captures the solar wind dynamic pressure for the thrust production. The artificial magnetosphere is generated by on-board superconducting coils, and a significant feature of the MPS spacecraft is the deployment of the magnetic field inflation, in which the small magnetosphere by the on-board coils is inflated by the static pressure of the low-speed plasma injected from the spacecraft. In this study, a parametric survey is conducted using the axis-symmetric two-dimensional magnetohydrodynamic (MHD) simulation to investigate the relation between the thrust characteristics and the released plasma parameters (mass flow rate and the thermal beta value at the releasing point). As a result, it is indicated that the maximum value of the thrust gain, which is defined as the ratio of the MPS spacecraft thrust force to the Magnetic Sail thrust force, is 3.77 when the thermal beta value is 25 and mass flow rate is 100 in the non-dimensional parameter (when the magnetospheric size is assumed as about 300 km, the thrust force is 60 N and the mass flow rate is 3.6 mg/s). In addition, the thrust gain and the specific impulse tend to be higher as the mass flow rate is lower and the thermal beta value is higher.