Unlike most of my others K2SE science blueprints, this is not an update of an old Nytromance Games plan, their A3 was bloated garbage, so I simply remade the whole thing from scratch.
I built this north of my A1 plan, directly north of its Astrometric Facilities. The garbage ejection lines feed into A1's garbage ejection lines. The Cold Thermofluid is being piped from my A2 plan, directly to the east, and the Blank Observation Frames is simply an straight-line extension of A2's line.
Factorio 2.0, Krastorio 2, Space Exploration 0.7x, stringweasel’s Valves mod, and xkyouchoux’s Space Age Building Integration mods. Should be easy to adjust without the last two.