Laboratory testing of the Mini-Magnetospheric Plasma Propulsion (M2P2) prototype

Abstract

Mini-Magnetospheric Plasma Propulsion (M2P2) seeks the creation of a magnetic wall or bubble (i.e. a magnetosphere) attached to a spacecraft that will intercept the solar wind and thereby provide high-speed propulsion with little expenditure of propellant. Results from a laboratory prototype that demonstrate the basic formation and expansion of a mini-magnetosphere are presented. The prototype uses a helicon source embedded asymmetrically in a dipole-like magnetic field. Breakdown of the plasma can be produced at neutral pressures of between about 0.25 to 1 mTorr to produce plasma densities of the order of 10 11-10 12 cm-3 with a temperature of a few eV. The plasma pressure is sufficient to cause the outward expansion or inflation of the mini-magnetosphere. The motion of both open and closed field lines within the vacuum chamber is demonstrated through the optical emissions from the helicon plasma. Inflation of the magnetosphere to several feet away from the magnetic coil and the equatorial confinement of the plasma are demonstrated. In space, inflation to about 15-20 km would be expected for the same configuration, which would potentially lead to the acceleration a 70-140 kg payload to speeds of about 50-80 km/s over a 3-month acceleration period. At this speed, missions to the heliopause and beyond can be achieved in under 10 yrs.

Solar Wind Sails

“…This propulsion system, illustrated in Fig.18, is called mini-magnetospheric plasma propulsion (M2P2) or MagnetoPlasma Sail (MPS). This idea gained great interest because the study by Winglee et al (Winglee, et al, 2001) suggested the possibility of dramatically large acceleration by M2P2 spacecraft in deep space.…”

“…The first experiment on the magnetic field inflation concept was tried by Winglee and his group (Winglee, et al, 2001;Ziemba, et al, 2001;Slough, et al, 2001;Giersch, et al, 2003). A highdensity helicon or an arc plasma source is located in a drum-like solenoid to observe magnetic field inflation.…”

Advances in magnetized plasma propulsion and radiation shielding

“…The set up of the simulations at the inner boundary is shown in Figure 1, and closely models the actual laboratory kW prototype 4,5 . A dipole magnet represented by a hollow (black/white) cylinder with a radius of 20 cm.…”

“…It is sufficient for example to produce differential erosion of surface material of Ganymede 1 and for the erosion of the Martian atmosphere 2 . At the same time there is potential for harnessing the solar wind for enhanced spacecraft propulsion, as suggested in MiniMagnetospheric Plasma Propulsion (M2P2) 3,4 . In this scheme a magnetic field attached to the spacecraft is expanded by the injection of plasma to a scale size of the order of 10 km.…”

Efficient Plasma Production in Low Background Neutral Pressures with the M2P2 Prototype

“…The M2P2 concept attempts to couple with the ambient solar wind to provide an overall power efficiency gain >> 1 with thrust levels predicted by simulation of several Newtons. 6 To accomplish this, plasma must be produced and injected along an imposed dipole magnetic field as has been previously described. 7 Plasma parameters required for the M2P2 concept are similar to those produced by helicon plasma sources.…”