Zero-G Fabrication Purpose & Scope This document defines conceptual and early-stage engineering approaches for manufacturing in microgravity (≈10⁻³–10⁻⁶ g) within the Leviathan self-replicating asteroid-mining architecture. Fabrication is the hardest autonomy bottleneck: most terrestrial manufacturing implicitly relies on gravity for settling, containment, separation, and degassing. In zero-g: Molten metals form spheres Powders drift and contaminate Bubbles do not rise Small disturbances scatter material The objective is not Earth-equivalent manufacturing, but robust, scalable, gravity-independent fabrication using asteroid-derived metals, silicates, and volatiles. Priority outputs: Structural wire, rods, tubes Coils and conductors Ceramic and SiC components Weldable feedstock for higher-order assembly --- 1. Core Zero-G Fabrication Constraints Material Behavior Liquids: surface tension dominates → droplets, adhesion Powders: float freely → dust clouds, sensor fouling Gases: remain trapped → poor degassing, porosity Containment & Shape Control No natural settling or pressing Artificial forces required: centrifugal, electromagnetic, pressure Cross-contamination risk between metals, silicates, volatiles Thermal Management Heat rejection only by radiation or forced convection Slow cooling without active quenching High thermal cycling stress on tooling Precision & Stability Vibrations propagate easily in micro-g Mining, spin systems, and propulsion must be isolated Energy-intensive processes compete with limited power budgets --- 2. Foundational Design Principles 1. Containment precedes shaping Material must be enclosed or field-controlled before melting or cutting. 2. Artificial gravity beats force application Centrifugal acceleration replaces presses, molds, and gravity settling. 3. Field-based heating over contact heating Induction and electromagnetic levitation minimize contamination. 4. Wire-first manufacturing Continuous wire and filament production is the most flexible feedstock. 5. Welding is the primary manufacturing step Complex geometry emerges from assembly, not casting. --- 3. Primary Fabrication Techniques Technique Role Zero-G Mechanism Strengths Limitations Leviathan Fit Centrifugal Foundry / Spinning Chamber Melting, casting, separation Rotation (1–10 rpm) creates 0.1–1 g equivalent Excellent containment; density separation Mechanical complexity Core fabrication “stomach” Induction Heating + EM Levitation Melting, purification Eddy currents heat & levitate conductors No crucible; high purity Power-intensive Dual-use with sorting Spun Conical Ceramic Extrusion Wire / filament Centrifugal pressure extrudes melt Continuous output Cooling critical Primary wire source Plasma / Magnetic Quenching Rapid solidification Confined plasma sheath removes heat Fast cooling; no contact Gas & power demand Preferred quench path Radiative / Vacuum Cooling Simple solidification Radiation + cold sinks Low complexity Slow Early bootstrap only Laser / Optical Sintering Ceramics, silicates Focused laser fuses powder Precision Dust management Secondary / later stage Electroplating (spinning) High-purity layers Centrifugal electrolyte flow Ultra-pure outputs Electrolyte sourcing Reserved for electronics Welding (primary fabrication) Assembly & repair Laser / arc / induction Highly versatile Needs wire feedstock Core fleet role --- 4. Quenching & Solidification Strategy Solidification is the dominant failure mode for zero-g fabrication. Preferred approaches: Plasma-sheath quenching Magnetically confined low-temperature plasma Helium or argon convective heat removal Minimal interaction with molten filament Inert gas jet cooling Pulsed argon/helium jets Simple, scalable, controllable Centrifugal thinning Higher spin → thinner wire → faster radiative loss Shadow / radiator extrusion Extrude toward cold sinks or asteroid night side --- 5. Purity & Cross-Contamination Control Selective induction heats metals, not silicates Centrifugal separation stratifies melts by density Multi-chamber processing sequence: 1. Melt + gross separation 2. Plasma or laser impurity removal 3. Levitation or electroplating for final purity Non-useful residues routed to waste ejection systems --- 6. Validation Lineage & Precedents NASA containerless processing & microgravity ISRU studies International Space Station electromagnetic levitation & welding experiments AstroForge & TransAstra concepts: induction vaporization and capture Zero-g extrusion and welding tests in orbital and parabolic environments These confirm that zero-g fabrication is difficult but tractable with the right assumptions. --- 7. Testing & Scale-Up Roadmap 1. Ground analogs Spin rigs, plasma quenching, induction tests 2. Parabolic flights / drop towers True micro-g extrusion and levitation 3. LEO prototypes Small centrifugal + induction free-flyers 4. NEA demonstrations Full collection → fabrication → welding loop --- Summary Zero-g fabrication is not Earth manufacturing without gravity — it is a different discipline entirely. The Leviathan approach accepts this by: Using spin instead of weight Fields instead of molds Wire instead of parts Welding instead of casting Once wire can be made reliably in space, everything else becomes assembly. --- Next Steps Notebook: zero_g_fabrication_sim.ipynb Diagram: collection → centrifugal melt → quenched wire → spool → welder Cross-links: zero-g-collection-anchoring.md power-solar-backbone/energy-scaling.md Project map & raw links: https://github.com/ksarith/Lazarus-Forge- [Lazarus Forge Discovery.md](https://raw.githubusercontent.com/ksarith/Lazarus-Forge-/main/Discovery.md) Project map & raw links: https://github.com/ksarith/Astroid-miner [Astroid-miner Discovery.md](https://raw.githubusercontent.com/ksarith/Astroid-miner/refs/heads/main/Discovery.md)