People do use radio (though not optical) for Earth-Moon-Earth data links: https://en.wikipedia.org/wiki/Earth%E2%80%93Moon%E2%80%93Earth_communication https://e

People do use radio (though not optical) for Earth-Moon-Earth data links: https://en.wikipedia.org/wiki/Earth%E2%80%93Moon%E2%80%93Earth_communication https://en.wikipedia.org/wiki/Earth%E2%80%93Moon%E2%80%93Ear...