/sci/ - Science & Math

>>16039716
>From what I gathered, they expected they might have a challenge pointing the antennas after landing so it was not off-nominal as far as I know. And remember there are unknowns about comm systems in the lunar south polar region because… /1
>2/…the Earth is low to the horizon and this can have unexpected consequences. Years ago I wrote a proposal inside NASA (that was not funded) to do a full end-to-end robotic mission test at the Haughton Mars research station in the Canadian High Arctic. Part of the justification
>3/…for the rest was that we do not know how end-to-end communications will perform from a geologically rough site with the antennas pointing not very high above the horizon. The problem is that radio signals skip off surfaces then they recombine with the signals that went in a…
>4/…straight line, and with the signals that skipped off all the other nearby surfaces. These signals can add together in and out of phase so the overall signal fades in amplitude. Because the site is geologically rough with little vegetation, you could get reflections that are
>5/…worse than usual. Then add into this that the soil on the Moon includes lots more glass than surfaces on Earth — like 50% or even as much as 80% glass by weight in the soil in some locations — and it could be even worse. And also on the Moon you have the effects of…
>6/…space plasma, solar wind, ultraviolet photoemission causing electrical charges that can spark and make electromagnetic noise, and cosmic/solar high energy particles affecting your equipment, and it adds up to huge uncertainty in how the comms will perform.
>So part of…