alt Hacker NewsYes, think about how this can be weaponized. Illuminate an area? Or, focus that energy on a single point and you've got sun powered space lasers?
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Except if the reflectors are shaped for wide area illumination, then their focal distance is probably nowhere near the distance from the satellites to the earth’s surface. So I don’t think is any “single point” to be had.
Heck, I haven’t done the math or anything but I bet even if you did instead use parabolic reflectors that were tuned to focus at the earth’s surface, it would still be very difficult to keep them aimed at a specific point for long enough to achieve significant heating. I wouldn’t be surprised if it’s difficult to achieve an increase in heating that’s close to, say, the heating difference from standing outside at noon as opposed to 5PM. Which then doesn’t do much because you couldn’t effectively use a reflector at noon, anyway. You’d want a lens instead. Or some sort of complicated Newtonian telescope type contraption.
Assuming the orbit is at 200km, these mirrors could only focus the image of the Sun on a 1.7km wide disk (that's (Sun diameter)/(Sun's distance)×(Earth distance)).
Moreover, the Sun's illuminance is about 1kW/m2 around Earth. 10000×60m2 satellite will thetefore intercept 600MW, so that's 260W/m2 on the focussed area. You're not going to burn anything with that.