From: utzoo!decvax!cca!REM@MIT-MC@sri-unix Newsgroups: net.space Title: Remote control mining Article-I.D.: sri-unix.3066 Posted: Thu Sep 2 00:12:36 1982 Received: Thu Sep 9 06:31:45 1982 From: Robert Elton MaasDate: 1 Sep 1982 09:08 PDT From: Ciccarelli at PARC-MAXC Why the insistence on Earth-based control of the mining machine? It's simpler to get it working that way. Eventually we want to automate it. With remote control, we need only solve the problems of getting the device there and maintaining communication with it. With automatic control we have to in addition find an algorithm that can replace a human worker, and debug it. Remember even the Voyager didn't make its own decisions, we radioed a sequence of commands to it and it merely executed them by rote. It took days to figure out a change before we could safely radio it up. We couldn't use interactive control because (1) too many things had to be done in too short a time, (2) the radio (speed of light) delay was much more than 3 seconds (more like a half hour each way) making interaction impossible, (3) motions had to be more precise than a human could do by servo. On the moon we have plenty of time to stop and retry something without losing a once-in-a-lifetime chance, only 3-second total delay, and no need to be especially unclumbsy. One possible way of positioning would be for the lander unit to shoot out lengths of fine wire which could be several hundred meters long and would be energized with a signal which the mining rover could detect. One more system that can fail. But maybe worth trying the second or third time. 1) Can a suitable mining area be located from lunar orbit (i.e. do you need to actually sift the sand or can you use remote-sensing techniques)? 2) Can a payload be set down in that area with suitable positioning accuracy? [I think present art would indicate "Yes" on both counts]. Good questions. Is SSI or anybody working on them? Re accurate locating, a rover to move from landing spot to work spot would help, as would a navagation system for the Moon similar to the one currently planned for Earth, allowing travel to within a couple meters of each other merely by subtracting coordinates and traveling "toward" each other accordingly. Anybody working on accurate lunar navigation?