I have seen papers on heliostat and rover regolith sintering for lunar manufacturing. It struck me that a more bitmapped approach on a much grander scale could be very cost effective. A very large, zero G, long focal length telescope mirror mounted in an equatorial low orbit satellite could trace out paths on the surface with a high energy focused beam pass after pass without expending significant energy in movement. Two opposing mirrors much like a very long focal length schmidt cassegrain telescope with the smaller mirror obstructing the center of the light headed into the large mirror from the sun and with the axis of the two mirrors on a radius from the center of the moon would be focusing the sunlight on the surface for a significant distance on the current orbit bright side of the moon with no gross motor movements. Fine motor movements could be tasked with tracing the desired sintered path. Yes, the focus will be slightly off at the edges of the active area. Do coarser resolution plotting near the edges. Yes, you must shift the tilt of your smaller mirror slightly as you scan a line.
The active area being 3D printed would move around the moon as the sunlight does and a moderately large percentage of each orbital pass would be non-functional. Ignore that dead time since you get a huge solar power rating for your sinterer and over many passes you access a huge lunar surface area. Since the process is efficient with delivered material and consumables, over time, you win. You can build a complete equatorial road for rovers using the technique and you can collect the product of your efforts when and where it is convenient from the edges of that road. Leave abrupt elevation changes(steep craters) fallow, Very slowly shift your orbit to circumnavigate fallow areas.
Techniques may need to be developed to precisely refresh the unsintered dust layer during the dead time of each orbit but realize that natural meteorite activity will be doing this some anyway and a minor trailing charged particle(electron/alpa) gun scan might provide enough particles attracted to the active area to collect a desired amount of new regolith dust where you want it. Fire the alphas so they embed into the target and the betas at surrounding dust.
For those who have a need for a question: Are we planning to do this already ? If not, why not ? The sooner we get it up there the sooner we will have an equatorial rover road lined with bricks to use to construct shelter.
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thewildotter
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