Comment Re:Hit or Miss (Score 1) 149
Why would tracking be slow? Parallax being what it is? As long as the mirror is tracking targets within the same quadrant of the sky, it should be able to switch fast enough.
As for modulation, I think you are making unstated assumptions about reflectivity and switching speeds. How are you imagining the focus to be shifted and reflectivity varied? Mylar held by variable stays, held taught by photion pressure, for example? Easy, point a big dish at a little dish for a two reflector system, and your traverse speeds (governed by mass) and modulation speed (also, to some extent governed by mass, depending on the method) are dramatically reduced, as now you only must move the smaller reflector.
I know very well about solar concentration with mirrors. A reflector array in the L1 would have the potential to extend the day cycle of a solar collection site.