According to [Lunar Crater Radio Telescope (LCRT) on the Far-Side of the Moon NASA Innovative Advanced Concepts (NIAC) Phase 1 Report][1], > We propose to deploy a 1km-diameter wire-mesh ... to form a > **sphericalcap** reflector. A spherical cap is a section of a sphere, not a parabola. Apparently the quote from Wikipedia in the OP is in error. [1]: https://www.nasa.gov/general/lunar-crater-radio-telescope-lcrt-on-the-far-side-of-the-moon/