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If you’re going to keep station over a pole, you’re going to be sitting there with no orbital momentum. This means that the always-present weight vector, pointing at the center of the earth, will have to be counteracted with an equal amount of upward thrust from some source or another, for the entire lifetime of the satellite.

(Of course, the higher the altitude, the less the weight for a given mass, and therefore the less the required thrust.)

It’s by no means obvious how they can utilize solar pressure in the polar sitting-case, since its force is always directed at 90 +/- 22 degrees from the needed direction. Converting that force into thrust using an ion engine, for instance, that could (1) Counteract the sunlight force itself, and (2) Provide levitating force equal to the weight of the satellite, would seem to violate the laws of Physics.

I can conclude only that they are assuming the presence consumable fuels onboard. But how long could such a satellite remain on station given the levitating impulse (thrust * time) available from any present or achievable or proposed, thruster technology? In terms of thrust alone, no presently achievable ion engine would even be close to supporting its own weight (even at, say, 40 000 KM), much less the weight of a practical satellite.

** Side note: Let us define a “classical” orbit as being one where the satellite is not subjected to external forces. This means that the orbit will be planar, with one focus at the center of the earth. (This leaves aside the secondary effects of solar pressure, drag from micro-atmosphere, and tidal irregularities from the earth, moon, and other massive objects.)

Now consider the case of a geosynchronous orbit in the plane of the equator. To “levitate” this orbit so that it follows a line of latitude away from the equator takes increasing amounts of thrust (power). The extreme case is considered above; viz., the polar-sitting case.