Investigations

Which NASA investigations come closest to your scenario, how they differ, and where each number comes from.

Your scenario

Shared with the Atlas through the link

atandwithin

for

Reference atmospheres

Finding

Microgravity · Material flammability · any material · PSI only

EvidenceDIRECT

D0.00computed

Nearest comparable run · BASS-II

partial match partial: compared on O₂ + pressure only. The nearest run does not record every axis; a missing axis can only make a run look closer. On all three axes: at D 2.02, NEAR.

Same verdict at every flow from 0 to 30 cm/s.

Evidence proximity, not a safety rating.

DIRECT / NEAR / DISTANT are MARGIN’s classifications, not established scientific classes. Method

Ranked catalogue

29 investigations · 3 with comparable runs for this question in microgravity. Strips show where each investigation’s runs sit on one axis; the amber rule is your scenario.

Sort

Comparable runs in this regime, ranked by R 3

BASS-IIPSI recordPSI-25129 comparable · 112 within NEARBASS-II, PSI record. 129 comparable · 112 within NEAR. O₂ 13.6–22.2 %, 129 of 129 runs recorded. Pressure 101.3 kPa, 129 of 129 runs recorded. Flow not recorded (“Flow restrictor”, “Fan display” only — no cm/s value). Nearest comparable run D 0.00, Evidence: DIRECT, partial: compared on O₂ + pressure only; on all three axes: none. 129 of 129 runs comparable.
“Flow restrictor”, “Fan display” only — no cm/s value
partial · all axes: none
129/129 comparable
SAFFIRE-IIPSI recordPSI-999 comparable · 9 within NEARSAFFIRE-II, PSI record. 9 comparable · 9 within NEAR. O₂ 21.5–22.1 %, 9 of 9 runs recorded. Pressure not recorded (no pressure column in the PSI table). Flow 20.0 cm/s, 9 of 9 runs recorded. Nearest comparable run D 2.02, Evidence: NEAR, partial: compared on O₂ + flow only; on all three axes: none. 9 of 9 runs comparable.
no pressure column in the PSI table
partial · all axes: none
9/9 comparable
SAFFIRE-IPSI recordPSI-982 comparable · 2 within NEARSAFFIRE-I, PSI record. 2 comparable · 2 within NEAR. O₂ 21.5 %, 2 of 2 runs recorded. Pressure 101.3 kPa, 2 of 2 runs recorded. Flow 20.0 cm/s, 2 of 2 runs recorded. Nearest comparable run D 2.02, Evidence: NEAR. 2 of 2 runs comparable.
2/2 comparable

No comparable runs, ranked on metadata only 21

SAFFIRE-IIIPSI recordPSI-100no O₂ recorded — not placeableSAFFIRE-III, PSI record. no O₂ recorded — not placeable. O₂ not recorded (no o₂ column in the PSI table). Pressure not recorded (no pressure column in the PSI table). Flow 30.0 cm/s, 2 of 2 runs recorded. No comparable run. 0 of 2 runs comparable.
no o₂ column in the PSI table
no pressure column in the PSI table
none comparable
0/2 comparable
BASSPSI recordPSI-26no O₂ recorded — not placeableBASS, PSI record. no O₂ recorded — not placeable. O₂ not recorded (no o₂ column in the PSI table). Pressure not recorded (no pressure column in the PSI table). Flow not recorded (no flow column in the PSI table). No comparable run. 0 of 121 runs comparable.
no o₂ column in the PSI table
no pressure column in the PSI table
no flow column in the PSI table
none comparable
0/121 comparable
ACME BREPSI recordPSI-20PSI has summary rows only — not runsACME BRE, PSI record. PSI has summary rows only — not runs. O₂ not recorded (summary rows only — not runs). Pressure not recorded (summary rows only — not runs). Flow not recorded (summary rows only — not runs). No comparable run. 0 of 0 runs comparable.
none comparable
18 summary rows
ACME CFI-GPSI recordPSI-159gas burner — not relevant to this questionACME CFI-G, PSI record. gas burner — not relevant to this question. O₂ 18.0–40.0 %, 179 of 333 runs recorded. 154 inverse-flame runs record a burner-fed oxidizer of 12–85% O₂, not ambient O₂ and not on this axis. Pressure 49.5–331.0 kPa, 333 of 333 runs recorded. Flow not recorded (no flow column in the PSI table). No comparable run. 0 of 333 runs comparable.
no flow column in the PSI table
none comparable
0/333 comparable
ACME CLD FlamePSI recordPSI-21PSI has summary rows only — not runsACME CLD Flame, PSI record. PSI has summary rows only — not runs. O₂ not recorded (summary rows only — not runs). Pressure not recorded (summary rows only — not runs). Flow not recorded (summary rows only — not runs). No comparable run. 0 of 0 runs comparable.
none comparable
32 summary rows
ACME E-FIELD FlamesPSI recordPSI-22PSI has summary rows only — not runsACME E-FIELD Flames, PSI record. PSI has summary rows only — not runs. O₂ not recorded (summary rows only — not runs). Pressure not recorded (summary rows only — not runs). Flow not recorded (summary rows only — not runs). No comparable run. 0 of 0 runs comparable.
none comparable
32 summary rows
ACME s-FlamePSI recordPSI-23PSI has summary rows only — not runsACME s-Flame, PSI record. PSI has summary rows only — not runs. O₂ not recorded (summary rows only — not runs). Pressure not recorded (summary rows only — not runs). Flow not recorded (summary rows only — not runs). No comparable run. 0 of 0 runs comparable.
none comparable
18 summary rows
ACME/Flame DesignPSI recordPSI-10gas burner — not relevant to this questionACME/Flame Design, PSI record. gas burner — not relevant to this question. O₂ 19.8–40.0 %, 207 of 327 runs recorded. 109 inverse-flame runs record a burner-fed oxidizer of 21–85% O₂, not ambient O₂ and not on this axis. Pressure 43.2–305.8 kPa, 307 of 327 runs recorded. Flow not recorded (no flow column in the PSI table). No comparable run. 0 of 327 runs comparable.
no flow column in the PSI table
none comparable
0/327 comparable
CFIPSI recordPSI-39liquid droplet — not relevant to this questionCFI, PSI record. liquid droplet — not relevant to this question. O₂ 17.0–21.0 %, 87 of 87 runs recorded. Pressure 50.7–506.6 kPa, 87 of 87 runs recorded. Flow not recorded (no flow column in the PSI table). No comparable run. 0 of 87 runs comparable.
no flow column in the PSI table
none comparable
0/87 comparable
DAFT / DAFT-2PSI recordPSI-47PSI has summary rows only — not runsDAFT / DAFT-2, PSI record. PSI has summary rows only — not runs. O₂ not recorded (summary rows only — not runs). Pressure not recorded (summary rows only — not runs). Flow not recorded (summary rows only — not runs). No comparable run. 0 of 0 runs comparable.
none comparable
2 summary rows
FLEXPSI recordPSI-69liquid droplet — not relevant to this questionFLEX, PSI record. liquid droplet — not relevant to this question. O₂ 12.0–34.0 %, 274 of 274 runs recorded. Pressure 70.2–309.3 kPa, 273 of 274 runs recorded. Flow not recorded (no flow column in the PSI table). No comparable run. 0 of 274 runs comparable.
no flow column in the PSI table
none comparable
0/274 comparable
FLEX-2PSI recordPSI-68PSI has summary rows only — not runsFLEX-2, PSI record. PSI has summary rows only — not runs. O₂ not recorded (summary rows only — not runs). Pressure not recorded (summary rows only — not runs). Flow not recorded (summary rows only — not runs). No comparable run. 0 of 0 runs comparable.
none comparable
8 summary rows
SAMEPSI recordPSI-102smoke source — not relevant to this questionSAME, PSI record. smoke source — not relevant to this question. O₂ not recorded (no o₂ column in the PSI table). Pressure not recorded (no pressure column in the PSI table). Flow 5.0–10.0 cm/s, 4 of 8 runs recorded. No comparable run. 0 of 8 runs comparable.
no o₂ column in the PSI table
no pressure column in the PSI table
none comparable
0/8 comparable
SAME-RPSI recordPSI-101smoke source — not relevant to this questionSAME-R, PSI record. smoke source — not relevant to this question. O₂ not recorded (no o₂ column in the PSI table). Pressure not recorded (no pressure column in the PSI table). Flow 0.0–8.1 cm/s, 109 of 109 runs recorded. No comparable run. 0 of 109 runs comparable.
no o₂ column in the PSI table
no pressure column in the PSI table
none comparable
0/109 comparable
SLICEPSI recordPSI-106PSI has summary rows only — not runsSLICE, PSI record. PSI has summary rows only — not runs. O₂ not recorded (summary rows only — not runs). Pressure not recorded (summary rows only — not runs). Flow not recorded (summary rows only — not runs). No comparable run. 0 of 0 runs comparable.
none comparable
12 summary rows
SPICEPSI recordPSI-107gas jet — not relevant to this questionSPICE, PSI record. gas jet — not relevant to this question. O₂ not recorded (no o₂ column in the PSI table). Pressure not recorded (no pressure column in the PSI table). Flow 0.7–85.3 cm/s, 436 of 469 runs recorded. No comparable run. 0 of 469 runs comparable.
no o₂ column in the PSI table
no pressure column in the PSI table
none comparable
0/469 comparable
BASS flame-spread modellingPSI recordPSI-62no experimental table in PSIBASS flame-spread modelling, PSI record. no experimental table in PSI. O₂ not recorded (no run table in PSI). Pressure not recorded (no run table in PSI). Flow not recorded (no run table in PSI). No comparable run. 0 of 0 runs comparable.
none comparable
no runs
Cool-flame CFDPSI recordPSI-117no experimental table in PSICool-flame CFD, PSI record. no experimental table in PSI. O₂ not recorded (no run table in PSI). Pressure not recorded (no run table in PSI). Flow not recorded (no run table in PSI). No comparable run. 0 of 0 runs comparable.
none comparable
no runs
Counterflow cool flamesPSI recordPSI-142PSI has summary rows only — not runsCounterflow cool flames, PSI record. PSI has summary rows only — not runs. O₂ not recorded (summary rows only — not runs). Pressure not recorded (summary rows only — not runs). Flow not recorded (summary rows only — not runs). No comparable run. 0 of 0 runs comparable.
none comparable
8 summary rows
SAME smoke modellingPSI recordPSI-115no experimental table in PSISAME smoke modelling, PSI record. no experimental table in PSI. O₂ not recorded (no run table in PSI). Pressure not recorded (no run table in PSI). Flow not recorded (no run table in PSI). No comparable run. 0 of 0 runs comparable.
none comparable
no runs
SPICE data analysisPSI recordPSI-60no experimental table in PSISPICE data analysis, PSI record. no experimental table in PSI. O₂ not recorded (no run table in PSI). Pressure not recorded (no run table in PSI). Flow not recorded (no run table in PSI). No comparable run. 0 of 0 runs comparable.
none comparable
no runs

Not ranked 4

Published groups are ranked only when published evidence is included.

BASS-II limitsPublished · not in PSIPUB-BASS-II-LIMITSpublished — not counted (toggle off)+1 1 g in other regimes, not drawnBASS-II limits, Published · not in PSI. published — not counted (toggle off). O₂ 13.5 %, 1 of 1 runs recorded. Pressure 101.3 kPa, 1 of 1 runs recorded. Flow not recorded (not reported in source). No comparable run. 0 of 2 runs comparable; 1 in earth (1 g) not drawn.
not reported in source
none comparable
not ranked0/2 comparable
LUCIPublished · not in PSIPUB-LUCIpublished — not counted (toggle off)+2 Moon in other regimes, not drawnLUCI, Published · not in PSI. published — not counted (toggle off). O₂ not recorded (no runs in this gravity regime). Pressure not recorded (no runs in this gravity regime). Flow not recorded (no runs in this gravity regime). No comparable run. 0 of 2 runs comparable; 2 in lunar (0.165 g) not drawn.
none comparable
not ranked0/2 comparable
Olson & Ferkul 2012Published · not in PSIPUB-OLSON-FERKUL-2012published — not counted (toggle off)+3 Moon, 3 Mars, 3 1 g in other regimes, not drawnOlson & Ferkul 2012, Published · not in PSI. published — not counted (toggle off). O₂ 17.0–24.0 %, 3 of 3 runs recorded. Pressure 70.3–101.3 kPa, 3 of 3 runs recorded. Flow 30.0 cm/s, 3 of 3 runs recorded. No comparable run. 0 of 12 runs comparable; 3 in lunar (0.165 g), 3 in martian (0.38 g), 3 in earth (1 g) not drawn.
none comparable
not ranked0/12 comparable
Saffire IV–VIPublished · not in PSIPUB-SAFFIRE-IV-VIpublished — not counted (toggle off)Saffire IV–VI, Published · not in PSI. published — not counted (toggle off). O₂ 22.0–31.0 %, 7 of 7 runs recorded. Pressure 54.1–100.0 kPa, 7 of 7 runs recorded. Flow 20.0 cm/s, 7 of 7 runs recorded. No comparable run. 0 of 7 runs comparable.
none comparable
not ranked0/7 comparable

Planned — not evidence 1

Planned conditions are never counted as evidence.

FM2PlannedPLAN-FM2planned — not evidence+6 Moon in other regimes, not drawnFM2, Planned. planned — not evidence. O₂ not recorded (no runs in this gravity regime). Pressure not recorded (no runs in this gravity regime). Flow not recorded (no runs in this gravity regime). No comparable run. 0 of 6 runs comparable; 6 in lunar (0.165 g) not drawn.
never counted comparable
not ranked0/6 comparable

How to read the strips

comparable run, within NEAR (D ≤ 2.5) on the other compared axes
comparable, but farther than NEAR on the other axes
not comparable for this question
nominal (stated) value
published (not in PSI)
reported limit: a threshold, not a test
planned: not evidence
not recorded
your scenario

Strips are marginal: a run close on O₂ can be far on pressure or flow, so a tick is drawn solid only when that run is also within NEAR on the other axes it is compared on. Only runs in the scenario’s gravity regime are drawn. Inverse-flame O₂ (fed through the burner) is noted under the O₂ strip, not placed on it. R components: P proximity, H hazard match, S scale, C coverage, M measurements.

Claim ledger

Every statement made for this scenario, typed and sourced: 24 statements. Sort by number, claim type or source; run ids open their provenance.

MEASUREDCOMPUTEDNOMINALREPORTED LIMITPUBLISHEDDRAFTPLANNED

Claim ledger: each statement for the current scenario with its claim type and source
		Statement
C1	COMPUTED	Evidence: DIRECT · nearest comparable run D = 0.00partial: compared on O₂ + pressure only. Evidence proximity, not a safety rating. On all three axes (O₂, pressure and flow): Evidence: NEAR (D = 2.02). 140 runs pass the comparability gate for “Material flammability” in microgravity (PSI only). Thresholds: DIRECT D ≤ 1, NEAR D ≤ 2.5. DIRECT / NEAR / DISTANT are classifications under MARGIN’s chosen method (D ≤ 1 / ≤ 2.5; one unit = 2 pts O₂, ×1.25 (25%) pressure or 5 cm/s flow), not established scientific classes. Method	SourceMARGIN engine · `evaluate()` · method
C2	MEASUREDNOMINALDRAFT	Nearest comparable run : 3/8" clear rod. O₂: 20.9 % measured MEASURED Pressure: 101.3 kPa (14.70 psia) nominal (stated, not measured) NOMINALDRAFT Flow: not recorded DRAFT: a stated value in this row is not yet checked against its primary source.	SourcePSI-25_Experimental table_BASS-II.csv · row 100 · PSI record (opens in a new tab) ↗
C3	COMPUTED	Gaps to that run (run − scenario); one unit = 2 pts O₂, ×1.25 pressure, 5 cm/s flow. Partial match: compared on O₂ + pressure only; flow not compared. O₂: ±0.0 pts (±0.00 units) Pressure: −0 % (−0.00 units) Flow: not compared — not recorded	SourceMARGIN engine · `distance()` · method
C4	COMPUTEDMEASUREDNOMINALDRAFT	Best run compared on all three axes: (SIBAL Fabric) — D = 2.02, Evidence: NEAR.	SourcePSI-98_Experimental table_SAFFIRE-1.csv · row 1 · PSI record (opens in a new tab) ↗
C5	COMPUTED	Across 27 combinations of ½×, 1×, 2× axis scales the verdict stays DIRECT. D spans 0.00–0.01. In 27 of the 27 combinations the nearest run is a partial match (not compared on every axis). “Changes under ½×/2× scales” describes the method’s sensitivity to its own assumptions, not fire behaviour.	SourceMARGIN engine · `robustness()` · method
C6	COMPUTED	Flow sensitivity: the verdict is the same at every flow below. Flow is one of the three compared axes, so a different assumed flow moves D. The verdict at each flow is in the Flow sensitivity table below.	SourceMARGIN engine · `evaluate() at each flow` · method
C7	NOMINALDRAFT	The nearest run’s pressure is nominal: stated in a document, not measured in the run. Flow recorded as uncalibrated fan/air display values; not converted to cm/s (PSI 'Fan calibration data.xlsx' mapping not applied). Pressure is nominal (stated), not measured. Paraphrase, not a quote: Tests at ISS cabin pressure; O₂ varied by N₂ dilution of the MSG working volume — BASS-II Summary Report, NASA/TM-20210011385 (as summarised in Discovery R3 §1; quote not yet verified).	SourcePSI-25_Experimental table_BASS-II.csv · row 100 · PSI record (opens in a new tab) ↗
C8	MEASUREDCOMPUTED	The highest O₂ in any of PSI’s 140 solid-material tests with a recorded O₂ value is 22.2%. 0 reach the Artemis habitat’s 26.5%; 0 reach the Exploration Atmosphere’s 34.0%. (1,870 PSI run rows; 857 record both O₂ and pressure.)	SourceNASA PSI run tables, fetched 14 Nov 2026 · psi.nasa.gov ↗
C9	COMPUTED	Of 1,899 runs and records: 140 comparable, 0 reported limits, 0 context only, 0 in another gravity regime, 1,759 excluded by the gate (other fuel class, no O₂, planned, or published while the toggle is off).	SourceMARGIN engine · `gate()` · method
C10	MEASUREDPUBLISHED	On the ISS, PMMA rods in low-speed forced flow kept burning at a lower O₂ than the 1-g upward-spread limit reported for the same material. 13.5% vs 15.4% O₂ · BASS-II, cast PMMA rods in concurrent flow, minimum of the flammability boundary at stretch rate 8–12 s⁻¹; the 1-g value is upward spread with an added 4 cm/s forced flow (Hirsch et al. 2003, as cited in the report). Published finding (measured). Scope: Cast PMMA rods (radius 0.318–0.635 cm) in the ISS Microgravity Science Glovebox. Not valid for: Other materials or geometries; partial gravity; rating any material. “13.5 percent O2 at a of 8 to 12 s⁻¹ is significantly lower than the observed upward flame spread limit of 15.4 percent O2”	SourceOlson et al., BASS-II Summary Report, NASA/TM-20210011385, §6.1.4.4, p. 76 (PDF p. 84) ↗
C11	MEASUREDPUBLISHED	Near the low-O₂ limit, PMMA rods on the ISS took far longer to ignite than the igniter-on time used in the NASA standard test, and ignition limits sat above flammability limits. up to ≈10× the standard igniter-on time · BASS-II, cast PMMA rods, hot-wire igniter, ISS Microgravity Science Glovebox; ignition attempts of up to 500 s failed at very low O₂. Published finding (measured). Scope: PMMA rods with one igniter design. Not valid for: Other igniters, materials or geometries. “The ignition delay time can be up to almost 10 times longer than the NASA STD–6001 standard igniter on time.”	SourceOlson et al., BASS-II Summary Report, NASA/TM-20210011385, §6.1.6, p. 89 (PDF p. 97); 500 s attempts §6.1.3, p. 67 (PDF p. 75) ↗
C12	MEASUREDPUBLISHED	Without buoyancy to carry it away, fuel vapour from heated samples accumulated and ignited as a sudden deflagration in two Saffire tests. 2 of 5 Saffire IV–V tests · Saffire IV-2 (2-sided PMMA, 100 kPa, 22% O₂, after flow was cut to 5 cm/s) and V-4 (structured PMMA, 72.6 kPa, 25.7% O₂, at ignition in 20 cm/s flow), conditions as in ICES-2021-266 Table 1. Published finding (measured). Scope: Two events in large-scale tests; the authors suggest curled ash upstream may have helped V-4. Not valid for: Predicting when or where a deflagration will occur. “Two Saffire samples (IV-2 and V-4) exhibited intense ignition processes of deflagration because of a stratified mixture”	SourceUrban et al., ICES-2021-266 (NTRS 20210011521), §III.B, p. 5; V-4 at ignition p. 7 ↗
C13	MEASUREDPUBLISHED	For Mylar at 10.2 psia, drop-tower tests found a lower limiting O₂ at lunar gravity than at either 0 g or 1 g: microgravity and Earth results did not bound lunar behaviour for this material. ULOI: Moon 15.6 · 0 g 17.0 · 1 g 21.2 % O₂ · Concurrent (upward) spread; 5.18 s drop tower with a rotating centrifuge for lunar g; 0 g with 30 cm/s concurrent flow; 1 g from WSTF tests with a hot-wire igniter; 10.2 psia. Published finding (measured). Scope: Mylar G, 5 mil film; reduced-g limit criteria (ULOI, MOC) differ from the 1-g criteria. Not valid for: A general rule for other materials (Nomex: Mars below Moon; Ultem: 0 g above 1 g). “the result is a significantly negative oxygen margin of safety (~4-5%) in Martian, Lunar, and 0g.”	SourceOlson & Ferkul, ICES-2012-3492 (NTRS 20130010991), Table I, p. 6; Mylar discussion p. 7 ↗
C14	MEASUREDPUBLISHED	The gravity effect on limiting O₂ depends on the material: Ultem's 0-g limit sat slightly above its 1-g limit, and Nomex's Martian-g limit sat below its lunar-g limit. Ultem ΔO₂ (0 g) +0.25 · Nomex ULOI* Mars 19.9 vs Moon 21.0 % O₂ · Same drop-tower study: Ultem 1000 at 10.2 psia, Nomex HT90-40 at 14.7 psia; 5.18 s tests. Published finding (measured). Scope: Two charring materials, one thickness each. Not valid for: Ranking gravity levels for untested materials. “For these charring materials, the oxygen margin of safety in 0g is very close to zero”	SourceOlson & Ferkul, ICES-2012-3492 (NTRS 20130010991), Table I, p. 6; charring-material discussion p. 7 ↗
C15	MEASUREDPUBLISHED	In Saffire-II, silicone sheets did not burn appreciably in microgravity at 20 cm/s, although the thinnest sheet burned almost completely in a 1-g upward test. μ-g burn length ≈ 0 for four silicone sheets (0.27–1.03 mm) · Saffire-II on Cygnus, silicone 5 cm × 29 cm, 20 cm/s concurrent or opposed flow, ≈22.1% O₂ (ISS reading); pressure not stated in this source. Published finding (measured). Scope: Four small silicone samples at one flow speed. Not valid for: Other flows, elevated O₂ or other materials. “Flammability of silicone in microgravity appears to be reduced compared to normal gravity, at least for the flow speeds tested.”	SourceFerkul et al., ICES 2017 slides (NTRS 20170008805), Table I, slide 29; summary, slide 26 ↗
C16	PUBLISHED	A NASA assessment of heritage ISS hardware states that many ISS materials meet flammability requirements at 10.2 psia and 30% O₂ but are unlikely to meet them at higher O₂. assessed up to 40% O₂ at 8.2 psia · Engineering assessment of 33 ISS and Orion subsystems for Exploration atmospheres (10.2 psia / 26.5% O₂ and 8.2 psia / 34% O₂). Published finding (stated). Scope: Heritage ISS materials named in the assessment (for example foam insulation, sound-block silicones). Not valid for: Any specific material without its own test record. “Many ISS materials have been shown to meet flammability requirements at 10.2 psia and 30% O2, but are unlikely to meet the requirements”	SourceAbney et al., ICES-2022-45 (NTRS 20220006612), p. 8 ↗
C17	PUBLISHED	NASA's challenge statement says PSI currently holds no partial-gravity combustion data. no partial-gravity combustion data in PSI (as stated) · NASA Space Apps 2026 “Flame in Freefall” challenge statement; LUCI and FM2 are named as expected future additions. Published finding (stated). Scope: The PSI combustion archive at the time of the challenge. Not valid for: Data outside PSI (drop-tower, aircraft, LUCI) or future PSI additions. “there is currently no partial-gravity combustion data available in PSI”	SourceNASA Space Apps Challenge 2026, Flame in Freefall, “Partial-gravity data” section ↗
C18	MEASUREDPUBLISHED	The flammability boundary for PMMA rods in microgravity is U-shaped in O₂ versus flow: flames go out at very low flow (quenching) and at high flow (blowoff), with the lowest O₂ in between. minimum ≈ 13.5% O₂ at stretch rate 8–12 s⁻¹ · BASS-II, cast PMMA rods in concurrent axial stagnation flow (0–55 cm/s duct flow); the minimum is reported as a stretch rate, not a single flow speed. Published finding (measured). Scope: Cast PMMA rods; NASA's 2015 guide describes the same shape for flame spread over solids generally. Not valid for: Converting the minimum to one flow speed for other geometries; untested materials. “This “Goldilocks” zone of flow is unfortunately typical of spacecraft ventilation flows near surfaces.”	SourceOlson et al., BASS-II Summary Report, NASA/TM-20210011385, §6.1.4.4, p. 76 (PDF p. 84) ↗
C19	MEASUREDPUBLISHED	In Saffire IV–VI, flames on thick PMMA did not spread along the sample; they stayed anchored at the leading edge and grew linearly, without the acceleration seen in upward burning in 1 g. 0.22–0.38 mm/s flame-length growth · Saffire IV–VI on Cygnus, PMMA 40 cm wide (5 or 10 mm thick), 20 cm/s duct flow, 22–30% O₂, 54–100 kPa (ICES-2026-577 Table 1). Published finding (measured). Scope: Four flat PMMA samples, burns of about 500 s; the 2-sided samples were still growing when the tests ended. Not valid for: Other fuels, clutter or cabin geometries; burns longer than tested. “The PMMA samples all showed intervals of very linear flame growth for periods of several minutes.”	SourceUrban et al., ICES-2026-577 (NTRS 20260001992), §III, p. 5; Table 1, p. 6 ↗
C20	MEASUREDPUBLISHED	The size of the flow enclosure changed flame spread over thin fabric: lowering the duct height from 46 cm to 30 cm roughly doubled the spread rate. ≈ +100% spread rate · SIBAL fabric 40–41 cm wide, 20–25 cm/s concurrent flow, ≈100 kPa, 21–22% O₂ (Saffire I and III vs IV, ICES-2021-266 Table 2). Published finding (measured). Scope: One fabric, two duct heights. Not valid for: Other enclosures or fuels without a model. “As expected, the spread rate increased (about 100%) with the reduced height flow duct compared to Saffire I and III.”	SourceUrban et al., ICES-2021-266 (NTRS 20210011521), §III.C and Table 2, p. 8 ↗
C21	MEASUREDPUBLISHED	On a rotating New Shepard flight at lunar g, a SIBAL fabric flame spread steadily downward for over a minute; with the same hardware in 1 g the flame went out about 45 s sooner. flame base 0.92 mm/s, tip 1.1 mm/s · LUCI, New Shepard (launched 4 Feb 2025), 11 rpm at 1.22 m radius, air at normal pressure, O₂ falling from ~20% to ~18% during the burn. Published finding (measured). Scope: One flight, one fabric sample; Coriolis force affected the flames; conference slides, not a peer-reviewed paper. Not valid for: Exploration atmospheres (air only), other materials, long-duration lunar-surface behaviour. “SIBAL fabric (cotton-fiberglass blend) burning downward in Lunar-g 30 s after ignition. The flame spread for over a minute.”	SourceFerkul et al., LUCI (NTRS 20250010653), slide 16 (caption), slide 19 (spread rates), slide 34 (1-g comparison) ↗
C22	MEASUREDPUBLISHED	In Saffire VI, the fires barely changed cabin temperature and pressure, while CO and CO₂ rose above crew exposure limits in the PMMA tests. ΔT 0.25–0.50 °C · ΔP 0.25–0.34 mbar · CO rise 122–338 ppm (24-h SMAC 100 ppm) · Saffire VI on Cygnus, free volume 16.7 m³, 54–55 kPa, 29–31% O₂; increases measured at the far-field unit over an unscrubbed baseline. Published finding (measured). Scope: One vehicle configuration with a direct flow path to the far-field unit. Not valid for: Other vehicle volumes, ventilation or fire sizes; battery fires. “Overall, the pressure rise and temperature change were small but the smoke particulate rose to substantial levels and the gaseous products also achieved hazardous levels.”	SourceUrban et al., ICES-2026-577 (NTRS 20260001992), abstract, p. 2; Table 1, p. 6 ↗
C23	MEASUREDPUBLISHED	At a 2 mg/m³ aerosol reference threshold, both Saffire VI PMMA fires were detected only after CO had already risen above the 24-hour crew limit. alarm at 1,037 s and 1,603 s · CO rise at alarm 105 and 283 ppm (24-h SMAC 100 ppm) · Saffire VI-3 and VI-4, PMMA, 54–55 kPa, 29–30% O₂, 20 cm/s duct flow; reference alarm = DustTrak aerosol reading at the far-field unit. Published finding (measured). Scope: One vehicle (free volume 16.7 m³) with a direct flow path to the detector; the authors' reference threshold, not a flight smoke detector. Not valid for: Well-mixed cabins, other detectors or placements; Saffire IV PMMA and VI SIBAL were detected before CO reached the 24-hour limit. “both PMMA samples from SAFFIRE VI exceeded the CO threshold with the 1-sided sample approaching the 1-hour SMAC”	SourceUrban et al., ICES-2026-577 (NTRS 20260001992), Table 1, p. 6; §III, p. 9 ↗
C24	MEASUREDPUBLISHED	Turning the airflow off did not reliably put fires out: a 2-sided PMMA flame survived 15 s without flow and a cotton fabric flame grew back after 70 s; holding 5 cm/s for 300 s before shut-off was followed by immediate extinction in two tests. 15 s and 70 s without flow · 5 cm/s for 300 s · Saffire IV-2 (PMMA, 100 kPa, 22% O₂), V-2 (cotton, 70.7 kPa, 26.2% O₂), V-3 and V-4 (PMMA, 71.3–72.6 kPa, 25.4–25.7% O₂), values as in ICES-2021-266 Table 1. Published finding (measured). Scope: Four tests on two flights. Not valid for: A general extinguishment procedure; the authors note it would carry other risks. “However, as an extinguishment strategy, this would carry other risks given the uncertainty of configurations and flow rates in a spacecraft.”	SourceUrban et al., ICES-2021-266 (NTRS 20210011521), §III.A, pp. 4–5 ↗

Flow sensitivity COMPUTED

Verdict at other ventilation flows, everything else as in your scenario (20.9% O₂, 101.4 kPa, microgravity, PSI only).

Verdict at other ventilation flows, everything else as in your scenario
Flow	Evidence	Nearest comparable run
0 cm/s (quiescent)	DIRECT	PSI-25:r0100 (partial)
5 cm/s	DIRECT	PSI-25:r0100 (partial)
10 cm/s · your scenario	DIRECT	PSI-25:r0100 (partial)
15 cm/s	DIRECT	PSI-25:r0100 (partial)
20 cm/s	DIRECT	PSI-25:r0100 (partial)
30 cm/s	DIRECT	PSI-25:r0100 (partial)