Here is the engineering specification

Surface units operate in local gravity 3.7 m/s2.

All units operate in a high-vacuum atmosphere approximately 0.5 nPa (0.005 picobars) in a temperature range of 100K-350K. I have my doubts about the pressure figures but it's still an ultra-vacuum. One unsolved problem is how to keep it that way while refining so much material.

Surface units: we require an assortment of minibots, railgun, railgun power storage, surface power collector, surface power distributor.

Orbiting units: we require orbiting factory unit, minibots, mirror, orbiting power distributor.

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