Global atmosphere (95.3% CO2 by volume)
Estimated Quantity
Average 600 Pa surface pressure (0.6% of Earth)
Pressure varies seasonally by ~25% as CO2 freezes/thaws at poles
As of 2021-01-01
Mars's thin CO2 atmosphere is paradoxically its most abundant ISRU feedstock. NASA's MOXIE instrument on Perseverance demonstrated oxygen production from CO2 in 2021 — the first ISRU demonstration on Mars. Full-scale MOXIE-like system ('MOXIE+') could produce the oxygen needed to fill a Mars Ascent Vehicle propellant tank over 26 months. CO2 can also be processed into CO/O2 bipropellant or combined with electrolyzed H2 to produce methane via Sabatier reaction.
MOXIE on Perseverance demonstrated O2 production from CO2 via SOXE (solid oxide electrolyzer) — 6g/hour at scale needed for launch propellant means scaling to 25 kg/day for MAV
Reality Check
Atmospheric density is only 0.6% of Earth's — thin enough that large collectors are needed; power requirements are substantial
Confidence: high · Last verified 2026-06-01
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