PSI recordPSI-99Investigation dossier

SAFFIRE-II

Spacecraft Fire Experiment-II

Principal investigator: David Urban
Platform: Cygnus Spacecraft
Hardware: Cygnus Pressurized Cargo Module, SAFFIRE
Dates: 09-30-2016 → 04-01-2017
Licence: CC0-1.0
PSI version: v5 · modified 04-Jun-2025
Publications listed: 7

PSI record (opens in a new tab)doi 10.60555/2chp-m469 (opens in a new tab)psi.nasa.gov/physci/repo/data/investigations/PSI-99

Evidence proximity, not a safety rating. This page describes what was tested and where each value comes from.

Footprint · Microgravity

Where SAFFIRE-II’s runs sit in condition space, in the Atlas chart window. Other investigations’ runs in this regime are dimmed.

0 of 9 runs drawn · 9 runs without O₂ or pressure are not drawn.

Source: NASA PSI run tables (snapshot 2026-11-14) and the published papers listed under Sources. Evidence proximity, not a safety rating; not a hazard map.

Objective

As written in the PSI record:

The objectives of SAFFIRE-II are to determine how rapidly a large scale fire grows in low-gravity and to investigate the low-g flammability limits compared to those obtained in NASA’s normal gravity material flammability screening test.

Fingerprint COMPUTED

Computed from the 9 run rows below: what varied, what was held constant, and what was never recorded.

Varied

O₂ 21.5–22.1 % · 3 levels · measured
Camera 1 · 8 values
Samle Thickness · 7 values
Camera 2 · 7 values
Burn Time (s) · 6 values
?-g Burn Length · 5 values
?-g Spread Length · 5 values
1-g Spread Rate · 5 values
Material · 4 values
+6 more source columns

Held constant

Flow 20.0 cm/s · measured
Sample Width (cm) = 5 cm
Air Flow (cm/s) = 20 cm/s

Not recorded

Pressure no pressure column in the PSI table

Condition axes: what varied and what was held constant
Axis	State	Range	Basis	Recorded
O₂	varied	21.5–22.1 % · 3 levels	measured	9/9
Pressure	not recorded	no pressure column in the PSI table	not recorded	0/9
Flow	held constant	20.0 cm/s	measured	9/9

Placeable: 9 of 9 record O₂ and can be placed (the engine can compute a distance); 0 also record pressure and appear on the charts.
Gravity: Microgravity (9)
Fuel classes: Solid · unclassified (8) · Solid · thin (1)
Flow regime: concurrent flow (8) · opposed flow (1)
Materials (5): Silicone (4) · not recorded (2) · Cotton-Fiberglass (SIBAL) (1) · PMMA & Nomex (1) · PMMA (1)
Outcomes: ignited (5) · other (4)
Measured quantities: burn time [s] (5) · sample thickness [mm] (4) · low-g spread rate (column labelled 'spread length') [mm/s] (2)
Per-run identifiers: Sample Number
Data-quality flags: approximate × 9: The source gives an approximate value or a range; the first value is used.
derived-value × 9: The value is derived from other measurements (see the note).
missing × 9: At least one of O₂, pressure or flow is not recorded in the source row.
text-parsed × 9: The number was parsed from text in the cell (for example “20 cm/s”).

Where the runs sit: O₂ × pressure, zoomed to the data

Nothing from this investigation can be placed on an O₂ × pressure chart: 9 runs: O₂ recorded but pressure not recorded.

Source: the normalized O₂ and pressure of each run in the run table below (NASA PSI run tables or the cited paper); the original cell and any conversion are in each run’s provenance. Reference atmospheres are MARGIN’s presets. Not a hazard map.

Run table

Normalized values with the original cell beneath each. Inspect a row for its conversions, flags, source and distance to your scenario. 6 non-run rows in the CSV (notes or headers) were not treated as runs.

SAFFIRE-II: 9 runs from PSI-99_Experimental table_SAFFIRE-2.csv.

SAFFIRE-II: 9 runs. Each value cell shows the normalized value and, beneath it, the original cell as it appears in the source.
Row	Material	Fuel class	g	O₂ %	Pressure kPa	Flow cm/s	Outcome	Flags
1	Silicone	Solid · unclassified	µg	21.5~ 21.5	not recorded—	20.0concurrent flow20 cm/s	other	approximate, derived-value, missing, text-parsed
2	Silicone	Solid · unclassified	µg	22.1~ 22.1	not recorded—	20.0concurrent flow20 cm/s	other	approximate, derived-value, missing, text-parsed
3	Silicone	Solid · unclassified	µg	22.1~ 22.1	not recorded—	20.0concurrent flow20 cm/s	other	approximate, derived-value, missing, text-parsed
4	Silicone	Solid · unclassified	µg	22.1~ 22.1	not recorded—	20.0opposed flow20 cm/s	other	approximate, derived-value, missing, text-parsed
5	Cotton-Fiberglass (SIBAL)	Solid · thin	µg	22.1~ 22.1	not recorded—	20.0concurrent flow20 cm/s	ignited	approximate, derived-value, missing, text-parsed
6	not recorded	Solid · unclassified	µg	22.1~ 22.1	not recorded—	20.0concurrent flow20 cm/s	ignited	approximate, derived-value, missing, text-parsed
7	PMMA & Nomex	Solid · unclassified	µg	22.1~ 22.1	not recorded—	20.0concurrent flow20 cm/s	ignited	approximate, derived-value, missing, text-parsed
8	PMMA	Solid · unclassified	µg	22.122.1 to 22.0	not recorded—	20.0concurrent flow20 cm/s	ignited	approximate, derived-value, missing, text-parsed
9	not recorded	Solid · unclassified	µg	22.022.0 to 21.9	not recorded—	20.0concurrent flow20 cm/s	ignited	approximate, derived-value, missing, text-parsed

Investigation dossier

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Reading the record, its runs and their sources.

SAFFIRE-II

Spacecraft Fire Experiment-II

Principal investigator

David Urban

Platform

Cygnus Spacecraft

Hardware

Cygnus Pressurized Cargo Module, SAFFIRE

Dates

09-30-2016 → 04-01-2017

Licence

CC0-1.0

PSI version

v5 · modified 04-Jun-2025

Publications listed

Evidence proximity, not a safety rating. This page describes what was tested and where each value comes from.

Fingerprint COMPUTED

Computed from the 9 run rows below: what varied, what was held constant, and what was never recorded.

Varied

O₂ 21.5–22.1 % · 3 levels · measured
Camera 1 · 8 values
Samle Thickness · 7 values
Camera 2 · 7 values
Burn Time (s) · 6 values
?-g Burn Length · 5 values
?-g Spread Length · 5 values
1-g Spread Rate · 5 values
Material · 4 values
+6 more source columns

Held constant

Flow 20.0 cm/s · measured
Sample Width (cm) = 5 cm
Air Flow (cm/s) = 20 cm/s

Not recorded

Pressure no pressure column in the PSI table

Condition axes: what varied and what was held constant
Axis	State	Range	Basis	Recorded
O₂	varied	21.5–22.1 % · 3 levels	measured	9/9
Pressure	not recorded	no pressure column in the PSI table	not recorded	0/9
Flow	held constant	20.0 cm/s	measured	9/9

Placeable

9 of 9 record O₂ and can be placed (the engine can compute a distance); 0 also record pressure and appear on the charts.

Gravity

Microgravity (9)

Fuel classes

Solid · unclassified (8) · Solid · thin (1)

Flow regime

concurrent flow (8) · opposed flow (1)

Materials (5)

Silicone (4) · not recorded (2) · Cotton-Fiberglass (SIBAL) (1) · PMMA & Nomex (1) · PMMA (1)

Outcomes

ignited (5) · other (4)

Measured quantities

burn time [s] (5) · sample thickness [mm] (4) · low-g spread rate (column labelled 'spread length') [mm/s] (2)

Per-run identifiers

Sample Number

Data-quality flags

approximate × 9: The source gives an approximate value or a range; the first value is used.
derived-value × 9: The value is derived from other measurements (see the note).
missing × 9: At least one of O₂, pressure or flow is not recorded in the source row.
text-parsed × 9: The number was parsed from text in the cell (for example “20 cm/s”).

Run table

SAFFIRE-II: 9 runs from PSI-99_Experimental table_SAFFIRE-2.csv.

SAFFIRE-II: 9 runs. Each value cell shows the normalized value and, beneath it, the original cell as it appears in the source.
Row	Material	Fuel class	g	O₂ %	Pressure kPa	Flow cm/s	Outcome	Flags
1	Silicone	Solid · unclassified	µg	21.5~ 21.5	not recorded—	20.0concurrent flow20 cm/s	other	approximate, derived-value, missing, text-parsed
2	Silicone	Solid · unclassified	µg	22.1~ 22.1	not recorded—	20.0concurrent flow20 cm/s	other	approximate, derived-value, missing, text-parsed
3	Silicone	Solid · unclassified	µg	22.1~ 22.1	not recorded—	20.0concurrent flow20 cm/s	other	approximate, derived-value, missing, text-parsed
4	Silicone	Solid · unclassified	µg	22.1~ 22.1	not recorded—	20.0opposed flow20 cm/s	other	approximate, derived-value, missing, text-parsed
5	Cotton-Fiberglass (SIBAL)	Solid · thin	µg	22.1~ 22.1	not recorded—	20.0concurrent flow20 cm/s	ignited	approximate, derived-value, missing, text-parsed
6	not recorded	Solid · unclassified	µg	22.1~ 22.1	not recorded—	20.0concurrent flow20 cm/s	ignited	approximate, derived-value, missing, text-parsed
7	PMMA & Nomex	Solid · unclassified	µg	22.1~ 22.1	not recorded—	20.0concurrent flow20 cm/s	ignited	approximate, derived-value, missing, text-parsed
8	PMMA	Solid · unclassified	µg	22.122.1 to 22.0	not recorded—	20.0concurrent flow20 cm/s	ignited	approximate, derived-value, missing, text-parsed
9	not recorded	Solid · unclassified	µg	22.022.0 to 21.9	not recorded—	20.0concurrent flow20 cm/s	ignited	approximate, derived-value, missing, text-parsed