# Mercury Extraction Pathway

> Active teardown. ~1 Tt/yr output. Continuous since ~2,900 CE.

## Operational figures

| Metric | Value |
|---|---|
| Output rate | ~10¹⁵ kg/yr (~32 Mt/s averaged) |
| Active shafts | ~14,000 |
| Mass-driver installations | ~430 |
| Beam allocation share | ~30–35% of swarm output |
| Continuous personnel | ~2.4 M (bonded + technical) |
| Cumulative removed | ~12–18% of original mass |
| Projected end | Sub-planetary remnant, mid-3,500s CE |

## Why Mercury

| Constraint | Mercury | Comparison |
|---|---|---|
| Escape v | 4.25 km/s | Venus 10.36, Earth 11.19 |
| Surface energy to escape | ~9 MJ/kg | Venus ~53 MJ/kg |
| Atmospheric drag | Zero | Venus dominant |
| Mineralogy | Iron-nickel + silicate | Belt comparable, lower mass per body |
| Distance to beam delivery | 0.31–0.47 AU | Belt 2.2–3.2 AU |
| Political complication | None | Venus, Earth contested |

Decision formalized 2,890–2,910 CE. Has not been seriously revisited.

## Method

**Phased zoning.** Planet divided into ~100–500 km operational zones under SMA-arbitrated lease. ~80–120 active at any time.

**Sequence per zone (typically 80–200 years):**
1. Survey (high-res mapping)
2. Surface clearing → low-grade silicate ballast
3. Open-pit crust/upper-mantle extraction → bulk construction-grade feedstock
4. Shaft transition when overburden cost > deep-access cost
5. Mantle and core-adjacent extraction → highest value per unit, hardest

## Subsurface response

Decompression of a partially-extracted planetary mass produces operational terrain, not abated hazards:

- Density profile shifts (decade timescale)
- Phase boundary migration / crystallization fronts reorganize
- Continent-scale fracture systems
- Active tectonic relaxation
- Magnetic field fluctuations from convection changes

Infrastructure adapts to a continuously changing substrate. Shafts drilled vertical are now noticeably inclined. Installations abandoned and reconstructed elsewhere.

## Core exposure

Two zones reached partial core exposure: high northern (since ~2,950 CE) and small equatorial (since ~3,080 CE). Effective working depth 10–40 km into metallic interior.

**Managed as hot industrial objects.** Passive cooling of 10²³ kg metal would take ~10⁵ years. Thermal energy harvested as process heat; radiator swarms reject excess; insulation preserves molten zones where feedstock is more valuable than solid. Highest beam allocation, highest insurance, highest bonuses; recognized career step.

## Mass launch

**Surface mass drivers.** 60–320 km long. Continuous fire, not pulsed. Output 4.5–7 km/s. Each large driver ~10⁸ kg/yr; global fleet ~10¹⁵ kg/yr.

Power: ~50 MJ/kg launched (9 MJ/kg theoretical + 20% conversion loss + 30% margin) = **~1.5 PW total fleet draw** — 5–8% of total Dyson output.

**Dispersal by solar sail.** At 0.31–0.47 AU, photon pressure on statite-grade sail (~1.5 g/m² loading) exceeds local solar gravity. Sun pays for transit.

| Target | Distance | Transit |
|---|---|---|
| Inner-band swarm shells | Co-orbital | Weeks |
| Earth-shell elements (~1 AU) | ~0.6 AU | 6–14 mo |
| Mars-shell elements | ~1.1 AU | 1–3 yr |
| Outer-band shells | Up to 2.7 AU | 2–8 yr |

Heavier components ride tug-sails (higher loading, longer transit, ~10–25 yr to outer-band).

## Polymer matrix demand

Mercury feedstock is silicate+metal. **Every structure built from it is a composite needing polymer binder.** Net matrix consumption: ~22% of Mercury throughput → **~200 Gt/yr of Venusian slime demand**.

→ `polymer-matrix-demand.md`

## Labor

~2.4 M continuous personnel. Largest single bonded-labor concentration in inner system. SMA doesn't regulate Mercury labor directly; extraction consortia self-administer. Tacit accommodation in exchange for stable feedstock.

## End state

Operational completion mid-3,500s CE. Remnant transitions to maintenance extraction ~5% of current rate, supplying specialty alloys. Bulk pipeline shifts to outer-system or Venus terraforming. **End of Construction Spine era.** Current operators position for this transition centuries in advance.

→ `inner-solar-system.md`, `dyson-swarm.md`, `polymer-matrix-demand.md`, `terraforming-debate.md`