Makes me wonder if a giant, clear beach ball could be converted into a parabolic dish simply by spraying a ferrous-based paint on a section/hemisphere of it (with the receiver injected via the inflation tube).
(They didn't specify how 1/3 of the balloon's surface was "alluminized"... spraying would be a pretty easy way to do it, if it worked.)
(They didn't specify how 1/3 of the balloon's surface was "alluminized"... spraying would be a pretty easy way to do it, if it worked.)