15. 3) A – Autarky Mass Fraction
A · Autarky Mass Fraction = “What share of the survival-critical bill of materials do we actually supply locally, at spec, at steady cadence?” (volume & origin)
Autarky Mass Fraction is the share of survival the hub makes for itself. We measured it by count over a frozen chokelist, weighted by criticality and time-to-replace: seals, filters, pressure parts; disinfectants and med gases; glass, polymers, base metals; power devices and boards; the reagents that keep labs honest. What moves it are machine-tool lines with metrology teeth and supplier independence proofs that stand up in an audit. Proof is a spares ledger with >80% of critical SKUs fabricated locally and destructive tests that do not blink. Failure is a long import tail hiding inside pretty charts.
Quick Heuristic: R (Replication Capacity) vs A can be easily confused. The best analogy: Blueprints for a workshop vs steady delivery of timber. R is proving you can rebuild the workshop, certify it, and run it. A is the ongoing local supply of the materials and parts. Test: Did you commission a daughter line (R) or raise local share of the chokelist (A)?
Cross-pillar ties to A: M enables A by adding processes at spec; S reuses A’s criticality/time weights to size buffers; R needs A to reproduce the Base-Kit without imports; G polices substitution governance and emergency awards; P trains the people who keep lines running; E budgets heat/power for furnaces, kilns, and electrolysis.
Lessons Learnt: Delete the part or process first. We began by trimming the chokelist until it hurt—eliminating SKUs, fittings, and reagents that nobody would personally own. Anything that returned needed a named owner and a survival case. Only then did we drive localization. Autarky is the weighted, at-spec, steady-cadence share of the survival bill — not assembly theater. The origin factor (assembly < fab < ISRU chain) kept us honest.
Misjudged Initially:
Chased heroic parts (exotics, optics) and ignored bulk & urgent: water, O₂, glass, cement, seals.
Confused assembly with sovereignty; imported kits ≠ local supply.
Undercounted time-critical disposables (filters, steriles, reagents) that stockpile poorly.
Let departments own requirements; when everyone owns it, nobody does.
Failed to correct for quality (FPY, field failures) in the autarky numerator.
Qs to Ask:
What import did you keep on purpose, and what is the contingency when it stops?
For your top 10 items, what is the origin factor today, and who owns its improvement?
Which spec did you delete—and what fell away downstream when you did?
Port Harmonia, Mars (Year 94 Mars Human Era)
Here is a simplified example of Port Harmonia’s Autarky Mass Fraction MIS in the early third century HE:
A≈0.58
Take Dref=10,000, β=1, Hj=1. Compute wj ∝ dj⋅Ij⋅Tj. After normalizing wj and applying a^j, you’d get a pillar score roughly. (High weights on water/O₂ pull A up; partial localization of metals/polymers/steriles holds it below 0.6.)
Illustrative: Suppose a hub tracks 6 chokelist items
Item j | dj (kg/yr) | Ij | Tj | Mode ϕj | Local_output / demand | yj | Notes |
Oxygen | 180,000 | 1.00 | 1.00 | 1.00 | 0.95 | 0.98 | Electrolysis + Sabatier loop |
Water (potable/process) | 1,000,000 | 0.95 | 1.00 | 1.00 | 0.90 | 0.99 | ISRU + recycle |
Glass | 120,000 | 0.60 | 0.70 | 0.75 | 0.70 | 0.95 | ISRU sand + imported dopants |
Steel | 80,000 | 0.80 | 0.70 | 0.50 | 0.60 | 0.90 | Recycle + imported alloys |
Polymers | 40,000 | 0.70 | 0.60 | 0.50 | 0.40 | 0.85 | Monomer imports |
Sterile medical disposables | 6,000 | 0.90 | 0.90 | 0.50 | 0.30 | 0.92 | Local cleanroom, some reagents imported |
Interpretation:
A < 0.30 — Import-dominated; early ISRU/repair only.
0.30 – 0.60 — Mixed: the bulky/time-critical items (water/O₂/basic materials) localizing; long tail still imported.
> 0.60 — Strong autarky: most chokelist mass and high-criticality items local; imports are boutique or low-cadence.
> 0.90 — Near-total mass sovereignty; imports are discretionary or for performance.