On Behalf Of Paul Deema Couple of questions. I'd like to look at the reference (Advise reading the NASA description, to save extended speculation). Can you direct me? [Robert Bennett] Sure . see the reference list in GWW. Also, is LLR another program -- my reference describes it as LRRR. [Robert Bennett] LLR is the topic, not project, name. LLR = Laser Lunar Ranging More serious. Distance measuring -- especially to six inches or better -- requires a precise knowledge of the time the pulse was sent and sweeping to find the target would seem to preclude this. Is this covered in the NASA description also? [Robert Bennett] I forget. The pulses are coded for identification, so this would seem to answer your objection. But be sure to check the NASA description.