SPACECRAFT ATMOSPHERE & FIRE SAFETY ASSESSMENT
Evidence-grounded hazard assessment calibrated by 760 NASA spaceflight experiments across FLEX, BASS-II, SAFFIRE-I, SAME, and ACME CFI-G.
NASA flight experiments aboard the ISS (FLEX, BASS-II, SAME, ACME) and Cygnus (SAFFIRE-I) were performed in microgravity (~0 g). Planetary partial gravity (Moon 0.165g / Mars 0.38g) induces buoyancy-driven convective upward draft, continually replenishing oxidizer and accelerating flame propagation relative to quiescent orbital microgravity.
NASA Exploration Atmosphere (32% O2, 10.2 psi) to reduce spacewalk pre-breathe time while mitigating flammability.
[+] MATERIAL SELECTION & VENTILATION DRAFT (LEVEL 2) OPTIONAL BASS-II / SAFFIRE-I / SAME / ACME
[+] ADVANCED PRESSURE & GAS DILUENTS (LEVEL 3) CUSTOM GAS O₂, CO₂, He & N₂ MASS BALANCE
Routing inquiry -> Querying 760 flight records -> Calculating oxygen kinetics -> Synthesizing assessment
Cross-references mission parameters to correlate and activate relevant NASA microgravity combustion investigations.
EVIDENCE-GROUNDED SCIENTIFIC ASSESSMENT
FLEX (PSI-69) — FLAME EXTINGUISHMENT EXPERIMENT
Liquid droplet combustion kinetics (Methanol & Heptane), D²-law burning rate K (mm²/s), and inert gaseous dilution suppression (CO₂ and He).
D²-law burning-rate constant K (mm²/s) measured for Methanol and n-Heptane droplets across oxygen concentrations from 12% to 34%.
Initial droplet diameter D₀ (mm) versus recorded burn duration (s).
Effect of carbon dioxide suppressant dilution on droplet burning rate constant K (mm²/s).
BASS-II (PSI-25) — BURNING AND SUPPRESSION OF SOLIDS
Microgravity solid material flammability (PMMA Acrylic, SIBAL Fabric, Nomex) and toxic carbon monoxide (CO ppm) duct emissions.
Post-test duct carbon monoxide concentration (ppm). Values >= 500 ppm represent detector saturation. Local duct readings do not equate to whole-cabin volume exposure.
Initial ambient O₂ versus post-test ambient O₂ (%) across solid specimens with 1:1 no-depletion reference line.
SAFFIRE-I (PSI-98) — SPACECRAFT FIRE SAFETY DEMONSTRATION
Realistic 1-meter fabric flame spread test in uncrewed Cygnus cargo vehicle, showing steady flame propagation under concurrent ventilation versus flame extinction under quiescent conditions.
Sample S1 sustained 420s of steady flame spread at 20 cm/s airflow. Sample S2 quenched after igniter cutoff in quiescent conditions. Samples S3 and S4 were non-combustion airflow visualization smoke-wire diagnostics.
SAME (PSI-102) — SMOKE AEROSOL MEASUREMENT EXPERIMENT
Pyrolysis aerosol particle sizing for overheated spacecraft materials (Teflon, Kapton, Silicone, Lampwick) and detector response physics under microgravity absence of buoyant venting.
Microgravity promotes enhanced aerosol coagulation (>0.3 µm) for silicone and cotton pyrolysis, favoring optical/photoelectric detectors over ionization sensors.
Planned nominal matrix combinations relating carrier airflow velocity (cm/s) to material pyrolysis weight loss rate (mg/min).
ACME CFI-G (PSI-159) — ADVANCED COMBUSTION EXPERIMENTS
Cool flames investigation with gases: 179 Normal Flame tests and 154 Inverse Flame tests comparing spherical burner extinction limits and invisible chemical kinetics.
Calculated adiabatic flame temperature (K) versus measured peak burner temperature (°C) for ACME normal flames. Peak burner temperature is a hardware boundary and must be distinguished from gas flame temperature.
Operating pressure (bar) vs oxygen concentration (%). Note: For Normal flames, O₂ is in the ambient chamber. For Inverse flames, O₂ is injected through the burner into a fuel-filled chamber; it does NOT represent habitat atmosphere.
WHAT-IF ATMOSPHERIC COMPARISON SIMULATOR
Compare two spacecraft environments side by side to evaluate flammability risk, oxygen partial pressure shifts, and astronaut pre-breathe trade-offs.
ENVIRONMENT A: BASELINE
ENVIRONMENT B: TARGET
Percentage-point shift
-31.0 kPa shift
Crew respiration balance
Retrieved evidence shift
FLIGHT DATA DICTIONARY & RESEARCH DOIS
Standardized telemetry variable definitions, physical units, data types, and official Digital Object Identifiers (DOIs) across all 5 NASA microgravity combustion investigations.
| Investigation | Canonical Variable | Physical Unit | Role / Type | Scientific Definition & Meaning | Action |
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