The air molecules used by the ion engine as propellant go through channels in the satellite. The molecules aren't "caught" but instead pass through it and once they're ionized, the electromagnetic repulsion between the propellant and the satellite pushes them apart.
As long as the solar panels can supply enough energy, I don't see a problem. It isn't actually a perpetual motion machine as there's a constant energy input and there's no violation of conservation of momentum that I can see. The problem I think is more of an optimization - how big can they make the solar panels without adding too much drag? That will set a bound for how low these things can fly.
As long as the solar panels can supply enough energy, I don't see a problem. It isn't actually a perpetual motion machine as there's a constant energy input and there's no violation of conservation of momentum that I can see. The problem I think is more of an optimization - how big can they make the solar panels without adding too much drag? That will set a bound for how low these things can fly.