24 sources
D. P. Stocker
14 experiments since 2009; microgravity discovered non-premixed cool flames, and gas flames can burn steadily despite radiative loss.
D. L. Urban, G. A. Ruff, P. Ferkul, et al.
1.5–3.2 kW fires in a 17–19 m³ cabin: CO and CO₂ passed crew limits, while smoke was detected only at 981 s — after most toxic gas was released.
L. Carmignani, P. Garg, M. J. Gollner, C. Fernandez-Pello, M. Thomsen, D. L. Urban, G. A. Ruff
Spread rate is flat (~0.22 mm/s) from 60 to 100 kPa, then falls; radiation loss — not chemistry — limits the flame, as in low gravity.
M. Thomsen, L. Carmignani, C. Fernandez-Pello, S. Fereres, D. L. Urban, G. A. Ruff
Flame spread at lunar gravity ≈ 46 kPa on Earth, Mars ≈ 54 kPa, microgravity ≈ 33 kPa — but the physics behind the slowdown differs.
L. Carmignani, M. J. Gollner, C. Fernandez-Pello, M. Thomsen, S. Fereres, D. Urban, G. A. Ruff
Opposed flames spread at 50 kPa but not at 40 kPa — low-pressure extinction is sudden, not gradual.
D. L. Urban et al. (NASA GRC, JSC, ESTEC, ZARM, …)
Flames reached a limiting size, were 'pinned' at thick-fuel edges, shadowed downstream flames of oxygen — and one jumped a 4.5 cm gap.
M. Thomsen, C. Fernandez-Pello, G. A. Ruff, D. L. Urban
Lowering pressure slows flame spread toward the Saffire II microgravity value, but the flame colour (soot) is not reproduced — use with caution.
J. W. Marcum, P. V. Ferkul, S. L. Olson
Extrapolating the 1g blowoff line to zero stretch predicts a 13.4 % O₂ limit — close to the 13.6 % seen on the ISS. A new ground test method.
NASA Glenn Research Center
Steady spread is possible over a large fabric in low gravity, and concurrent spread is more sensitive to duct size than expected.
Saffire team (NASA GRC)
First large fire set on purpose in orbit: 1.8 mm/s, ~1200 W for 420 s; silicone did not burn and 'safe' Nomex would not ignite even in a pilot flame.
J. W. Marcum, S. L. Olson, P. V. Ferkul
Buoyancy adds a stretch of ~78 s⁻¹ (≈ 16.5 cm/s of flow); correcting for it aligns ground data with the ISS boundary.
J. E. Brooker, D. L. Dietrich, S. A. Gokoglu, D. L. Urban, G. A. Ruff
Detailed CFD (FDS) shows local O₂ depletion but takes days per case; lumped-capacity models can run hundreds of cases for relief-valve and hatch design.
P. V. Ferkul, S. Bhattacharjee, C. Fernandez-Pello, F. Miller, S. L. Olson, F. Takahashi, J. S. T'ien
PMMA burned steadily at 13.6 % O₂ in orbit while the 1g limit is 16 % — a negative oxygen margin of safety of 2.4 %.
P. V. Ferkul, S. L. Olson, F. Takahashi, M. Endo, M. C. Johnston, J. S. T'ien
Tiny flames on thick fuels burned for over 5 minutes, could go undetected, and a nitrogen jet failed to put one out — they can flare up if airflow rises.
O. Minster, B. Toth, G. Legros, … D. L. Urban, G. A. Ruff, et al. (International Topical Team)
No full-scale fire test had ever been run for crewed spacecraft — a large test on an unmanned Cygnus would close that gap.
L. K. Clayman, S. L. Olson, S. A. Gokoglu, J. E. Brooker, P. V. Ferkul, H. F. Kacher
In a 6.35 m³ sealed chamber, a heat exchanger in the plume cut pressure rise from 1.369 psi to ~0.20 psi — key for relief-valve sizing.
P. Ferkul, S. Olson, M. Johnston, J. T'ien
In orbit the fabric burned against the airflow (opposed), which is impossible in 1g air — clear proof of enhanced flammability in microgravity.
International Topical Team (IAC-12.A2.2.2)
Drop-tower data shows a negative Oxygen Margin of Safety: materials burn at lower O₂ in low and partial gravity than the 1g test allows.
Y. Son, P. D. Ronney, S. Gokoglu
At µg, flames can spread faster in CO₂ than in N₂ or He because CO₂ radiates heat to the fuel; helium is ~11× more effective by mass.
G. A. Ruff, M. Hicks, W. Mell, R. Pettegrew, A. Malcom
In 142 low-gravity data points there was no clear boundary between flames that CO₂ put out and those it did not — flow, surface heat and g-jitter all matter.
K. Nishizawa, O. Fujita, K. Ito, M. Kikuchi, S. L. Olson, T. Kashiwagi
With CO₂ dilution, wire-insulation flames spread fastest in still air and showed an unsteady secondary flame — unlike N₂.
NASA Glenn (proceedings, many authors)
In microgravity a flame becomes spherical and dim blue, and on Mir a fire went out faster at flow shutoff (< 13 s) than in normal gravity (55 s).
A. V. Ivanov, Ye. V. Balashov, T. V. Andreeva, A. S. Melikhov
Each plastic has a limiting airflow Vlim (PMMA 0.5 cm/s); shutting off the vent flow extinguished every flame in 5–20 s.
R. Friedman, D. L. Urban
A gentle ventilation flow extends the microgravity flammability range to ~15 % O₂, well below the 21 % limit seen in still air — so the safety factor of 1g testing is suspect.
* Year inferred from the content — see the paper for details. Card summaries are short paraphrases; the drawer shows the exact wording.