it is a simple concept capable with a 15 mile (similar) square mirror, but I would guess capability is limited to no more than several hundred yards square for the present, or actual sky coverage size, if this was / is the question.
Wouldn't it be cool if a system of mirrors like that could be used to light up large areas on the Earth at night?
It would be a more useful endeavor if such a system were also used to generate power for use on planet Earth. Then again, there would be the usual nervous nellies worried about the potential such a thing would have as a weapon (would would then be exploited by vested interests afraid of losing a chokehold on energy sources).