Constraint III · Oxygen
Oxygen comes from water.Mars has enough water.
§06Constraint III · Oxygen
Requirement (alveolar gas equation)
pO₂,alv = 0.21 × (1013 − 47) − 50 = 153 mbar
Target: ≥ 130 mbar minimum, ~160 mbar comfortable
Target: ≥ 130 mbar minimum, ~160 mbar comfortable
Mass required
160 mbar × 3.88×10¹⁵ = 6.2×10¹⁷ kg O₂
= 1.94×10¹⁹ mol
= 1.94×10¹⁹ mol
Route: 2 H₂O → 2 H₂ + O₂
Requires 7.0×10¹⁷ kg water ≈ 4.8 m global equivalent layer.
Against 20–40 m accessible. 15–25% of the inventory. The water exists.
The CO₂ shortfall everyone leads with does not block oxygenation. It blocks pressure.
Energy floor
1.94×10¹⁹ mol × 572 kJ/mol = 1.11×10²⁵ J
At 60% electrolysis efficiency ≈ 1.9×10²⁵ J
At Type I power (10¹⁶ W): ~35 years of output
At 60% electrolysis efficiency ≈ 1.9×10²⁵ J
At Type I power (10¹⁶ W): ~35 years of output
MOXIE (Perseverance) caveat
MOXIE produced 122 g total, ~12 g/hr peak on ~300 W. Extrapolating a demonstrator to 10¹⁸ kg is not informative; the energy floor is the meaningful statement.
Interactive · Iteration 01
TOOL PENDING
Atmosphere Builder
Two sliders (total pressure, O₂ fraction). Live derivation of atmospheric mass, O₂/N₂ partial masses, water required in metres of global equivalent layer, alveolar pO₂ with verdict, and N₂ as a fraction of Titan's atmosphere. Ships in Iteration 1.