PSI-99 · SAFFIRE-II
“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.” [PSI JSON: objective]
“The Saffire-II experiment was performed on the Orbital Science’s Cygnus resupply vehicle after it deberthed from the ISS.” [PSI JSON: approach]
Overview
Objective [text]
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.
Source
data/raw/psi-data/PSI-99/_investigation/PSI-99.json: objective · PSI investigationApproach [text]
The Saffire-II experiment was performed on the Orbital Science’s Cygnus resupply vehicle after it deberthed from the ISS. As a follow on to the Saffire-I investigation, the Saffire-II investigation added more samples including SIBAL, silicone, structure PMMA, flat PMMA, and PMMA with Nomex. The Saffire-1I flight unit had a sample card installed in the middle of a large flow duct. Air is drawn through the flow duct by fans located at the top of the duct with flow straighteners at the bottom of the experiment module. Saffire-II has a sample card that contains 9 samples, each 5 cm x 29 cm. Depending on the sample material, the Saffire-II was conducted at an air flow velocity of either 20 or 30 cm/s, the flow being either concurrent or opposed. Once the sample was ignited flame images were captured using two cameras. In addition, thermocouples provided flow, flame, and plume temperatures, two radiometers recorded flame radiation, solid state sensors were used to measure pressure, CO2 and O2 mole faction, and two anemometer tracked flow velocity. All data was compressed, and subsequently downlinked. Details related to samples and experimental parameters are provided in the Experimental Details file in the Science document folder.
Source
data/raw/psi-data/PSI-99/_investigation/PSI-99.json: approach · PSI investigationHypothesis [text]
This investigation hypothesizes that due to large differences between fire behavior in normal and reduced gravity, the use of terrestrial fires and fire standards to design spacecraft fire safety systems presents an inherent risk to the vehicle because of the significant level of uncertainty. While this approach has been successful thus far, the uncertainty and risk will increase as exploration missions venture further from earth with considerably longer transit times for a safe return. There is a significant lack of microgravity data available for spacecraft designers on which to base their fire safety designs and procedures. To address this knowledge gap, this investigation proposed to conduct large-scale fire safety experiments in an expendable spacecraft without risk to a crew.
Source
data/raw/psi-data/PSI-99/_investigation/PSI-99.json: hypothesis · PSI investigationResearch impacts [text]
The Saffire-II experiment provides a new way to study a realistic fire on an exploration vehicle, which has not been possible in the past because the risks are too high. Instruments on an unmanned cargo vessel measure oxygen, carbon dioxide, heat, pressure and flame growth, and two video cameras provide views of the flame. Results determine microgravity flammability limits for several spacecraft materials, help to validate NASA’s material selection criteria, and how microgravity and limited oxygen affect flame size. The investigation is crucial for the safety of current and future space missions. Studying fire in small, sealed environments such as the Cygnus cargo supply vehicle benefits fire safety and prevention efforts on Earth, including inside mines, airplanes, or submarines.
Source
data/raw/psi-data/PSI-99/_investigation/PSI-99.json: researchImpacts · PSI investigationHardware [text]
Cygnus Pressurized Cargo Module, SAFFIRE
Source
data/raw/psi-data/PSI-99/_investigation/PSI-99.json: experimentHardware · PSI investigationFlight program [text]
Cygnus Spacecraft
Source
data/raw/psi-data/PSI-99/_investigation/PSI-99.json: flightProgram · PSI investigationStart date [text]
09-30-2016
Source
data/raw/psi-data/PSI-99/_investigation/PSI-99.json: investigationStartDate · PSI investigationEnd date [text]
04-01-2017
Source
data/raw/psi-data/PSI-99/_investigation/PSI-99.json: investigationEndDate · PSI investigationTests
9 tests with extracted table records (SAME-R aging sub-runs grouped by parent ID) · 50 extracted values (source: data/conditions/PSI-99.csv).
Variation is observed in extracted values; it does not establish the experimental design.
| Variable | Observed | Distinct values / tests | Range |
|---|---|---|---|
| flow_configuration [data/conditions/PSI-99.csv] | distinct values as recorded | 2 / 9 | concurrent, opposed |
| flow_velocity [data/conditions/PSI-99.csv] | observed constant | 1 / 9 | 20 cm/s |
| material [data/conditions/PSI-99.csv] | distinct values as recorded | 4 / 7 | Cotton-Fiberglass (SIBAL), PMMA, PMMA & Nomex, Silicone |
| o2_mole_fraction [data/conditions/PSI-99.csv] | distinct values as recorded | 4 / 9 | 0.215, 0.219..0.22, 0.22..0.221, 0.221 |
| outcome:burn_time [data/conditions/PSI-99.csv] | measured | 5 / 5 | 115 s – 900 s |
| sample_thickness [data/conditions/PSI-99.csv] | varied | 6 / 5 | 0.27 mm – 10 mm |
Loading test data…
Additional outcome cells, where available, are displayed as written. Source: data/derived/outcomes_extra.csv.
µg vs 1 g, same sample, as recorded
The local SAFFIRE-II CSV header reads “?-g” in the source file; its original microgravity symbol is not preserved there. Values are shown as written. The thickness “037 mm” is flagged as ambiguous in the extraction.
| Sample | ?-g burn length | ?-g spread length | 1-g burn length | 1-g spread rate | Thickness as recorded |
|---|
Instruments mentioned in the approach
No instrument sentence identified in the approach text.
Experimental table columns
- Material [table] data/raw/psi-data/PSI-99/Experimental table/PSI-99_Experimental table_SAFFIRE-2.csv · PSI investigation
- Samle Thickness [table] data/raw/psi-data/PSI-99/Experimental table/PSI-99_Experimental table_SAFFIRE-2.csv · PSI investigation
- Sample Length [table] data/raw/psi-data/PSI-99/Experimental table/PSI-99_Experimental table_SAFFIRE-2.csv · PSI investigation
- Sample Width (cm) [table] data/raw/psi-data/PSI-99/Experimental table/PSI-99_Experimental table_SAFFIRE-2.csv · PSI investigation
- Air Flow (cm/s) [table] data/raw/psi-data/PSI-99/Experimental table/PSI-99_Experimental table_SAFFIRE-2.csv · PSI investigation
- Percent O2 (Note 1) [table] data/raw/psi-data/PSI-99/Experimental table/PSI-99_Experimental table_SAFFIRE-2.csv · PSI investigation
- Ignition Power (W) [table] data/raw/psi-data/PSI-99/Experimental table/PSI-99_Experimental table_SAFFIRE-2.csv · PSI investigation
- Ignition Time (s) [table] data/raw/psi-data/PSI-99/Experimental table/PSI-99_Experimental table_SAFFIRE-2.csv · PSI investigation
- Burn Time (s) [table] data/raw/psi-data/PSI-99/Experimental table/PSI-99_Experimental table_SAFFIRE-2.csv · PSI investigation
- Flow Direction [table] data/raw/psi-data/PSI-99/Experimental table/PSI-99_Experimental table_SAFFIRE-2.csv · PSI investigation
- ?-g Burn Length [table] data/raw/psi-data/PSI-99/Experimental table/PSI-99_Experimental table_SAFFIRE-2.csv · PSI investigation
- ?-g Spread Length [table] data/raw/psi-data/PSI-99/Experimental table/PSI-99_Experimental table_SAFFIRE-2.csv · PSI investigation
- 1-g Burn Length [table] data/raw/psi-data/PSI-99/Experimental table/PSI-99_Experimental table_SAFFIRE-2.csv · PSI investigation
- 1-g Spread Rate [table] data/raw/psi-data/PSI-99/Experimental table/PSI-99_Experimental table_SAFFIRE-2.csv · PSI investigation
Data
Publications
- Buoyant Effects on the Flammability of Silicone Samples Planned for the Spacecraft Fire Experiment (Saffire), Conference: 45th International Conference on Environmental Systems ICES-2015-[293] 12-16 July 2015, Bellevue, Washington [data/manifest/publications.csv]
- The Spacecraft Fire Experiment (Saffire) - Objectives, Development and Status [data/manifest/publications.csv]
- Flame spread: Effects of microgravity and scale 10.1016/j.combustflame.2018.10.012 [data/manifest/publications.csv]
- Buoyancy effects on concurrent flame spread over thick PMMA 10.1016/j.combustflame.2018.10.016 [data/manifest/publications.csv]
- Concurrent Flame Spread Over Two-Sided Thick PMMA Slabs in Microgravity 10.1007/s10694-019-00863-3 [data/manifest/publications.csv]
- Transient flame growth and spread processes over a large solid fabric in concurrent low-speed flows in microgravity – Model versus experiment 10.1016/j.proci.2018.05.168 [data/manifest/publications.csv]
- Evaluation of gas and particle sensors for detecting spacecraft-relevant fire emissions 10.1016/j.firesaf.2020.102977 [data/manifest/publications.csv]
Data reuse
Not stated in PSI [not in PSI] data/raw/psi-data/PSI-99/_investigation/PSI-99.json: related_glds · PSI investigation
Other PSI records that list this investigation
- PSI-98 [text] data/raw/psi-data/PSI-98/_investigation/PSI-98.json: related_glds
- PSI-100 [text] data/raw/psi-data/PSI-100/_investigation/PSI-100.json: related_glds
These are links recorded in PSI; their presence alone does not describe the reuse relationship.
PSI page
PSI page data/manifest/web_check_2026-11-14.csv: line 1 URL pattern