Sadly you can't fire a heat ray back. At the focal point, rays will be coming from all across the primary reflector. Whatever shape mirror you place there, the rays will spread out again after bouncing off it.
(If the primary was smoothly curved and formed a sharp image at the focus, you could place a convex mirror in front of the focus to project a beam back, but with the primary mirror being made up of many flat elements, that wont work.)
Would you find a moment to talk about Our Lord Jesus Christ?
Would you find a moment to talk about Our Lord Jesus Christ?