Not directly on point, but ham radio people have been doing EME for a number of years: EME = Earth-Moon-Earth transmissions. The Moon isn't a particularly good corner reflector at any wavelength, but it's a lot bigger than the little Apollo corner reflector. https://en.wikipedia.org/wiki/Earth%E2%80%93Moon%E2%80%93Earth_communication At 02:07 PM 10/17/2015, Bill Gosper wrote:
A story I've been telling about the Apollo 11 array is apparently completely apocryphal: The McDonald Observatory was dismayed to receive no return signal, and feared the departing ascent stage blew dust on the array. (Supposedly they were enjoined by NASA from plinking the landing site before the astronauts departed.) Becoming even more dismayed by assurances that the corner reflectors *exceeded* spec, someone finally calculated that Earth rotated several thousand feet during the laser pulse transit time, duly separated the transmitter from the receiver, and became joyful. But https://www.youtube.com/watch?v=VmVxSFnjYCA (poor video) has Mythbusters visit the Apache Point Observatory and supposedly put to rest the Moon landing hoax hoax by getting a paltry few photons back from gigawatt pulses, apparently with receiver and transmitter in the same building. Perhaps even the same instrument? Could the observatory possibly be unable to afford separate transmitter and receiver? Or is the spread of the reflected signal so huge as to dwarf the calculated separation?
Anyway, from these few photons Mythbusters triumphantly conclude we walked on the moon, conveniently forgetting the retroreflector arrays on the Lunakhod rovers. Refuting conspiracy theories is a waste of time, especially when the refuters do a bad job. --rwg