Yeah, what you just stated about a concave mirror is not only ludicrous, but would be very destructive to the wilderness and wildlife and probably would be time to contact every wilderness and wildlife defense group to have this so called start-up shut down.

A concave mirror would focus all of the light from a wide area into a single point. What you've created there is a giant space laser. One that only works at night because you need the sun on the opposite side of the Earth to reflect it.

Also all of the previous problems about it needing to be massive, or close to the Earth and moving faster apply.