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 to accelerate the spacecraft in the solar wind direction by capturing the solar wind energy. MPS’s significant feature is it’s a utilization of magnetic field inflation process, in which a small magnetosphere by on-board coils is inflated by low-speed plasma released 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 injected plasma parameters (the mass flow rate and the thermal beta value at the injection point). As a result, the thrust gain, which is defined as the ratio of the MPS spacecraft thrust force to the Magnetic Sail thrust force, and the specific impulse have the maximum value against the thermal beta value, and in addition, increases with lower mass flow rate. It is indicated that the maximum value of the thrust gain is 3.77 when the thermal beta value is 25 and the mass flow rate is 100 in the non-dimensional parameter (when a magnetic moment of the spacecraft is assumed 6.28x10⁷ Wb・m, the thrust force is 60 N and the mass flow rate is 3.6 mg/s).