Ray\curve mirror problem

Question

I have an idea for a space station, but there is the following problem.

I have a patch of grass on a space station. If the sun (yellow rays) shines from below it, what is the best shape of mirror (gray curve) to hang above it and reflect back onto the grass?

Thanks!

Answer 1

Hint: The real world applications of parabolas are exactly this situation. Depending on how you want illumination over the grass, modification to the original parabola (moving the focus down) suffices, otherwise play with the parabola formula a bit

Answer 2

You don't want to much light on your grass, as to much may well cook it or set it ablaze. In my view, in this case, a simple flat or slightly convexe mirror could very be the best solution.