Just as it is applied to EDS systems on the Earth, the general theory of moments for electrodynamic magnetic levitation systems based upon the dynamic circuit principles and emphasized on the loop-shaped coil and the figureeight- shaped null-flux coil suspension could be modified and fully applied in space. The cross-connected null-flux superconducting EDS technology applied in the Maglev trains technology in Japan is especially suitable to be modified and applied in space. It is characterized by very low magnetic drag at low speed, high suspension stiffness, high lift to drag ratio and high guidance to drag ratio. SCMs suited on the propelled module will spin in a field created by a ring of magnets suited on the guideway. The only clearances to be controlled are those between electrodynamically propelled rotating cylinder-shaped module and the internal cylinder-shaped sidewalls of the nonrotating guideway. Propulsion of the electrodynamic repulsive system can be described as "pull - neutral - push". The propelled module is able to remain centered thanks to a combination of attraction and repulsion forces. Rotation is totally stable without any electronics control thanks to stabilizing Eddy currents induced by permanent magnets. This effect is normally referred to as the electrodynamic repulsion principle. Null-flux and double-layered propulsion coils are suitable to be applied as they allow instantaneous adaptation to changes in the circular trajectory. Generation of controlled magnetic forces and rotating magnetic field between magnetic body (the rotating module) and magnetized body (the rotation generator) will obtain stable and contactless rotation.

Unified Propulsion & Guidance System

     The aim of use of electrodynamic technologies is to obtain fully controlled rotation of habitat for generating gravity sensation by means of guidance and velocity control by a unified rotation and trajectory control system for uninterrupted and total control of propulsion, trajectory, and contactless rotation itself. The unified rotation and trajectory control system is electro-magnetic guideway consisting of propulsion and guidance subsystems.

     The rotating module has to be in the same axis with the rotation generator being guideway at the same time. This way they can be concentric and with uniform radial gap. The path is completely circular and unique and it can not be changed nor modified. Radial and axial centering can be achieved by the magnetic field generated by the radial set of null-flux figure-eightshaped coils attached on the inside hull of the rotation generator and the radial set of SCMs attached on the external surface of the rotating module. Sets of the SCMs jointed in outer aluminum made vessels with incorporated electromagnetic shields, that are radially inserted in the electromagnetically propelled rotating module, will produce permanent magnetic field. The sets are not to be continually inserted but in facing pairs. The other magnetic field is induced from the changes of the field that occur as the SCMs moves relative to the radial set of conductors located in the guideway. The relative motion between the rotating module and the rotation generator creates a repulsive magnetic fields to hold the two objects apart. As the rotating module rotates, there is voltage induction in the coils due to the relative motion of the magnet-coil system. This voltage creates current flow except at equilibrium position, resulting in a secondary magnetic field in opposition to the change in flux due to relative motion.

     So-called figure-eight-shaped null-flux coils similar to those applied in the Japanese EDS Maglev trains could be applied in space to act as trajectory and guidance control coils. They are to be installed on the inner surface of the circular rotation generator guideway and covered with aluminum curved-shaped panels. The guidance null-flux coils are placed over the propulsion coils which are arranged in one or even two overlapping layers to reduce the external electromagnetic disturbances influencing the SCMs mounted sequentially around the outer surface of the rotating module. Each pair of facing eight-shaped coils can be cross-connected by null-flux cable under the guideway constituting a loop.  This concept includes high guidance-to-drag ratios and very low magnetic drag at low speed. The null flux makes the power losses in the guideway from the induced currents in metal loops very low resulting in smaller magnetic drag forces. The null flux coils enable strong and fast acting trajectory control forces being inherently and passively stable. The coils must have high mechanical strength to bear magnetic forces so they are wound aluminum conductors molded out of unsaturated polyester resin reinforced with glass fiber and electrical insulated. The rotating module is guided and driven by superconducting coils mounted sequentially around the inner surface of the rotating generator characterized by a strong magnetic field which enable larger gap between the rotating module and the rotation generator. The choice of operating gap in space is a design decision. Larger gaps improve safety, allow greater construction tolerances and decrease construction costs. Lower sensitivity is very convenient for the circular movement.

     It is possible to develop three different designs of the electrodynamic rotation generator where all basic principles are equal and unchanged except there are three different arrangements of the SCMs, null-flux coils and propulsion coils.
- Radial thrust rotation generator, allready described above.
- Axial thrust rotation generator that includes the cross-connected figure-eight shaped null-flux coils and the propulsion coils suited on the both circular walls of the rotation generator and SCMs suited on the both faces of the cylindrical-shaped rotating module as it is shown in the figure.
- Combined axial/radial thrust rotation generator that combines the first two concepts.