[
 {
  "id": "low-flow-sensitivity",
  "source_id": "bass-thickness",
  "in": "pdf",
  "quote": "Microgravity flames were found to be especially sensitive to air flow speed in the range 0 to 5 cm/s.",
  "topics": [
   "airflow"
  ],
  "kind": "observed",
  "pdf_page": 54
 },
 {
  "id": "dim-blue-low-flow",
  "source_id": "bass-thickness",
  "in": "pdf",
  "quote": "At the lowest speeds examined (less than 1 cm/s) all the flames tended to become dim blue and very stable. However, heat loss at these very low convective rates is small so the flames can burn for a long time.",
  "topics": [
   "airflow",
   "detection"
  ],
  "kind": "observed",
  "pdf_page": 54
 },
 {
  "id": "tiny-flame-undetected",
  "source_id": "bass-thickness",
  "in": "abstract",
  "quote": "This has implications for spacecraft fire safety since a tiny flame might be undetected for a long time. While the small flame is not particularly hazardous if it remains small, the danger is that it might flare up if the air convection is suddenly increased or if the flame spreads into another fuel source.",
  "topics": [
   "detection",
   "airflow"
  ],
  "kind": "interpretation"
 },
 {
  "id": "flames-survive-below-1",
  "source_id": "bass2-summary",
  "in": "pdf",
  "quote": "Flames survived at airflow less than 1 cm/s.",
  "topics": [
   "airflow"
  ],
  "kind": "observed",
  "pdf_page": 74
 },
 {
  "id": "sibal-quench-speeds",
  "source_id": "sibal-concurrent",
  "in": "abstract",
  "quote": "The quenching speeds were found to be between 1 and 5 cm/s with higher speed in lower oxygen atmosphere.",
  "topics": [
   "airflow",
   "oxygen",
   "quench"
  ],
  "kind": "observed",
  "experiments": "family:SIBAL fabric · concurrent flow"
 },
 {
  "id": "sibal-first-boundary",
  "source_id": "sibal-concurrent",
  "in": "abstract",
  "quote": "This is the first time that a low-speed quenching boundary in concurrent spread is determined in a clean and unambiguous manner.",
  "topics": [
   "quench"
  ],
  "kind": "interpretation"
 },
 {
  "id": "sibal-spread-trends",
  "source_id": "bass2-summary",
  "in": "pdf",
  "quote": "Flames spread more slowly across the narrower samples, at lower flow velocities and at lower O2 percentages.",
  "topics": [
   "airflow",
   "oxygen",
   "geometry"
  ],
  "kind": "observed",
  "experiments": "family:SIBAL fabric · concurrent flow",
  "pdf_page": 103
 },
 {
  "id": "sibal-10-vs-5",
  "source_id": "bass2-summary",
  "in": "pdf",
  "quote": "Compared with the 10-cm/s case, the 5-cm/s case has a shorter flame and spreads more slowly.",
  "topics": [
   "airflow"
  ],
  "kind": "observed",
  "experiments": [
   "sibal-GMT96-T7",
   "sibal-GMT96-T8"
  ],
  "experiments_basis": "The report's Figures 7.2 and 7.3 (2.2-cm sample, 21 % O2, 10 and 5 cm/s) do not name test IDs; GMT96-T7 and GMT96-T8 are the only Table 7.1 tests with exactly these conditions.",
  "pdf_page": 103
 },
 {
  "id": "sibal-10-duration",
  "source_id": "bass2-summary",
  "in": "pdf",
  "quote": "The whole combustion process took about 40 s.",
  "topics": [
   "airflow"
  ],
  "kind": "observed",
  "experiments": [
   "sibal-GMT96-T7"
  ],
  "experiments_basis": "Figure 7.2 conditions (2.2-cm sample, 10 cm/s, 21 % O2) match only GMT96-T7 in Table 7.1.",
  "pdf_page": 103
 },
 {
  "id": "sibal-5-duration",
  "source_id": "bass2-summary",
  "in": "pdf",
  "quote": "Because the flow speed is lower, it took more than 60 s to burn the whole sample.",
  "topics": [
   "airflow"
  ],
  "kind": "observed",
  "experiments": [
   "sibal-GMT96-T8"
  ],
  "experiments_basis": "Figure 7.3 conditions (2.2-cm sample, 5 cm/s, 21 % O2) match only GMT96-T8 in Table 7.1.",
  "pdf_page": 103
 },
 {
  "id": "pmma-rod-limits",
  "source_id": "pmma-rods-concurrent",
  "in": "abstract",
  "quote": "Both blowoff and quenching limits were obtained at several oxygen concentrations.",
  "topics": [
   "oxygen",
   "blowoff",
   "quench"
  ],
  "kind": "observed"
 },
 {
  "id": "quench-mechanism",
  "source_id": "pmma-rods-concurrent",
  "in": "abstract",
  "quote": "Quenching was observed when the flow became sufficiently weak that the flame could no longer provide adequate heat flux to compensate for the heat losses (conduction into the rod and radiation).",
  "topics": [
   "quench",
   "airflow"
  ],
  "kind": "interpretation"
 },
 {
  "id": "low-g-burns-lower-o2",
  "source_id": "partial-g",
  "in": "abstract",
  "quote": "Previous testing at microgravity and Lunar gravity indicated that some materials burned to lower oxygen concentrations in low gravity than in normal gravity, although the low g extinction limit criteria are not the same as 1g due to time constraints in drop testing.",
  "topics": [
   "partial-gravity",
   "oxygen"
  ],
  "kind": "observed"
 },
 {
  "id": "factor-of-safety",
  "source_id": "partial-g",
  "in": "abstract",
  "quote": "If proven for more materials, this may indicate the need to include a factor of safety on 1g flammability limits.",
  "topics": [
   "partial-gravity"
  ],
  "kind": "interpretation"
 },
 {
  "id": "luci-first-lunar",
  "source_id": "luci",
  "in": "abstract",
  "quote": "These are the first-ever, extended-duration (greater than 25 seconds) combustion tests performed in simulated Lunar gravity.",
  "topics": [
   "partial-gravity"
  ],
  "kind": "observed"
 },
 {
  "id": "luci-fm2",
  "source_id": "luci",
  "in": "abstract",
  "quote": "Finally, the experiment is a steppingstone to the ultimate goal of performing burn tests on the Lunar surface in the Flammability of Materials on the Moon (FM2) experiment which is planned to launch in late 2026.",
  "topics": [
   "partial-gravity"
  ],
  "kind": "observed"
 },
 {
  "id": "fm2-measurements",
  "source_id": "fm2-plan",
  "in": "abstract",
  "quote": "The results of flame size, spread rate, atmosphere changes, and extinction oxygen concentration will then be analyzed and used to help quantify the risk and mitigation for future exploration missions.",
  "topics": [
   "partial-gravity"
  ],
  "kind": "context"
 },
 {
  "id": "fm2-atmospheres",
  "source_id": "fm2-atmospheres",
  "in": "abstract",
  "quote": "The environmental control system can replicate and conduct fire experiments automatically in the expected atmospheres, specifically 21% oxygen at 14.7 psia, and 34% oxygen at 8.2 psia, which are of immediate interest to the Human Lander System (HLS) and Lunar Rover.",
  "topics": [
   "partial-gravity",
   "oxygen",
   "pressure"
  ],
  "kind": "context"
 },
 {
  "id": "fm2-samples",
  "source_id": "fm2-atmospheres",
  "in": "abstract",
  "quote": "There are four samples currently planned; two SIBAL fabrics (cotton/fiberglass blend) which will be burned in air and two acrylic rods which will be burned in Normoxic Space Exploration Atmospheres (SEA).",
  "topics": [
   "partial-gravity",
   "materials-screening"
  ],
  "kind": "context"
 },
 {
  "id": "sibal-lunar-downward",
  "source_id": "fm2-atmospheres",
  "in": "abstract",
  "quote": "SIBAL fabric has been found to only burn downward in air in lunar gravity (via Lunar gravity centrifuge and parabolic flight) where on Earth’s gravity it extinguishes immediately after ignition.",
  "topics": [
   "partial-gravity",
   "materials-screening"
  ],
  "kind": "observed"
 },
 {
  "id": "lunar-goldilocks",
  "source_id": "fm2-atmospheres",
  "in": "abstract",
  "quote": "Lunar gravity has been found to increase the limits of flammability for some materials compared to Earth gravity, presenting a goldilocks zone of reduced convective heat loss, while generating enough buoyant flow to replenish fresh oxygen into the flame zone.",
  "topics": [
   "partial-gravity",
   "oxygen"
  ],
  "kind": "interpretation"
 },
 {
  "id": "confinement-small-gap",
  "source_id": "confinement",
  "in": "abstract",
  "quote": "For all baffle types, the flame either fails to ignite or extinguishes before reaching the end of the sample when the inter-baffle distance is too small (~ 1 cm). This is attributed to the reduction of oxygen supply to the flame zone and heat loss to the baffles.",
  "topics": [
   "confinement"
  ],
  "kind": "observed"
 },
 {
  "id": "exploration-atmosphere",
  "source_id": "exploration-atmosphere",
  "in": "abstract",
  "quote": "An “exploration atmosphere” of 56.5 kPa (8.2 psia), 34% O2, 66% N2 has been recommended by NASA for future Moon and Mars missions as a compromise that balances subsequent pre-EVA prebreathe duration, hypoxia, and flammability risk, assuming a 29.6 kPa (4.3 psi) spacesuit.",
  "topics": [
   "oxygen",
   "pressure",
   "partial-gravity"
  ],
  "kind": "observed"
 },
 {
  "id": "alt-exploration-atmosphere",
  "source_id": "ea-alt",
  "in": "abstract",
  "quote": "Fourteen volunteers completed 11-day hypobaric chamber studies with an “alternate exploration atmosphere” of 66.2kPa, 28.5% O2.",
  "topics": [
   "oxygen",
   "pressure"
  ],
  "kind": "context"
 },
 {
  "id": "enriched-o2-flammability",
  "source_id": "ea-alt",
  "in": "abstract",
  "quote": "In previous studies, we validated a prebreathe protocol from a 56.5 kPa 34% O2 cabin to a 29.6 kPa EVA pressure; however, the enriched oxygen cabin environment poses a flammability risk that requires significant changes to material design and selections.",
  "topics": [
   "oxygen",
   "pressure",
   "materials-screening"
  ],
  "kind": "context"
 },
 {
  "id": "proposed-ea-66",
  "source_id": "ea-6",
  "in": "abstract",
  "quote": "Subjects acclimated for 48 hrs at the proposed Exploration Atmosphere (66.2kPa, 28.5% O2) and then participated in five 6-hour simulated EVAs at 29.6 kPa, 95% O2.",
  "topics": [
   "oxygen",
   "pressure"
  ],
  "kind": "context"
 },
 {
  "id": "saffire-vs-bass",
  "source_id": "confinement",
  "in": "pdf",
  "quote": "While steady flame spread was also observed, the flame spread rates at the steady state in Saffire were significantly lower than those obtained in BASS even at the same oxygen percentage and flow rate. The different spread rates were suspected to be due to the different confined conditions introduced by the large and small flow ducts used in these two experiments.",
  "topics": [
   "confinement",
   "geometry"
  ],
  "kind": "observed",
  "pdf_page": 2
 },
 {
  "id": "bass-duct",
  "source_id": "bass2-summary",
  "in": "pdf",
  "quote": "The tests were performed in the 250-L free volume Microgravity Science Glovebox (MSG) in the Destiny Lab of the International Space Station (ISS).",
  "topics": [
   "apparatus"
  ],
  "kind": "observed",
  "pdf_page": 74
 },
 {
  "id": "bass-duct-size",
  "source_id": "bass2-summary",
  "in": "pdf",
  "quote": "The flow duct measured 7.6 by 7.6 by 17 cm with rounded internal corners for smooth laminar flow through the duct.",
  "topics": [
   "apparatus"
  ],
  "kind": "observed",
  "pdf_page": 74
 },
 {
  "id": "blowoff-kinetics",
  "source_id": "bass2-summary",
  "in": "pdf",
  "quote": "As the opposed-flow velocity is increased, the residence time being inversely proportional to the square of velocity, finite-rate kinetics in the gas phase becomes important leading ultimately to the blowoff extinction.",
  "topics": [
   "blowoff",
   "airflow"
  ],
  "kind": "interpretation",
  "pdf_page": 28
 },
 {
  "id": "radiative-regime",
  "source_id": "bass2-summary",
  "in": "pdf",
  "quote": "studies have established the radiative regime in the mild opposed-flow environment in which the flame spread rate decreases as the opposed-flow velocity is reduced leading to flame extinguishment (Ref. 10) if the flow velocity is sufficiently low.",
  "topics": [
   "quench",
   "airflow"
  ],
  "kind": "interpretation",
  "pdf_page": 28
 },
 {
  "id": "hw-duct",
  "source_id": "bass2-summary",
  "in": "pdf",
  "quote": "The black anodized 7.6- by 7.6- by 17-cm rectangular flow duct with rounded corners was originally built to perform gas jet diffusion flame studies (Ref. 10).",
  "topics": [
   "apparatus"
  ],
  "kind": "observed",
  "pdf_page": 12
 },
 {
  "id": "hw-fan",
  "source_id": "bass2-summary",
  "in": "pdf",
  "quote": "The flow was blown through the duct using a variable speed fan.",
  "topics": [
   "apparatus"
  ],
  "kind": "observed",
  "pdf_page": 12
 },
 {
  "id": "hw-straightener",
  "source_id": "bass2-summary",
  "in": "pdf",
  "quote": "The flow then passed through a honeycomb flow straightener and an inlet screen to reduce swirl.",
  "topics": [
   "apparatus"
  ],
  "kind": "observed",
  "pdf_page": 12
 },
 {
  "id": "hw-radiometer",
  "source_id": "bass2-summary",
  "in": "pdf",
  "quote": "Inside the test section was a nozzle for N2 flow, a movable scale, and an Oriel® 71768 thermopile detector (Newport Corporation) with a CaFl window (spectral range of 0.13 to 11 µm) in the downstream top back corner of the duct viewing the upstream direction.",
  "topics": [
   "apparatus"
  ],
  "kind": "observed",
  "pdf_page": 12
 },
 {
  "id": "hw-still-camera",
  "source_id": "bass2-summary",
  "in": "pdf",
  "quote": "The top window was used by a Nikon D300s 12.3-megapixel digital color still camera with a 60-mm lens that provided 4,320- by 2,968-pixel images.",
  "topics": [
   "apparatus"
  ],
  "kind": "observed",
  "pdf_page": 12
 },
 {
  "id": "hw-video",
  "source_id": "bass2-summary",
  "in": "pdf",
  "quote": "The video camera had an overlay that displayed the N2 flow rate (cm3/min), fan voltage (10× V), air velocity transducer reading (cm/s), and the radiometer signal.",
  "topics": [
   "apparatus"
  ],
  "kind": "observed",
  "pdf_page": 13
 },
 {
  "id": "hw-igniter",
  "source_id": "bass2-summary",
  "in": "pdf",
  "quote": "The samples were manually ignited with a Kanthal® A–1 29-gauge hot-wire igniter coil with a nominal hot wire resistance of 0.8 to 1 Ω, powered by 3.5 to 3.8 amps when the astronaut manually pulled the deployment lever to move the igniter into position.",
  "topics": [
   "apparatus"
  ],
  "kind": "observed",
  "pdf_page": 13
 },
 {
  "id": "hw-samples",
  "source_id": "bass2-summary",
  "in": "pdf",
  "quote": "The flat samples were 1 or 2 cm wide.",
  "topics": [
   "apparatus"
  ],
  "kind": "observed",
  "pdf_page": 13
 },
 {
  "id": "hw-exit",
  "source_id": "bass2-summary",
  "in": "pdf",
  "quote": "The duct exit contained a perforated copper plate followed by a brass screen to provide heat rejection and a cold surface for soot deposition.",
  "topics": [
   "apparatus"
  ],
  "kind": "observed",
  "pdf_page": 12
 },
 {
  "id": "hw-nitrogen",
  "source_id": "bass2-summary",
  "in": "pdf",
  "quote": "Working volume of MSG was diluted using ISS N2 gas.",
  "topics": [
   "apparatus"
  ],
  "kind": "observed",
  "pdf_page": 12
 },
 {
  "id": "saffire-first-large-fire",
  "source_id": "saffire-1-3",
  "in": "pdf",
  "quote": "For the first time, a large-scale fire was intentionally set inside a spacecraft while in orbit.",
  "topics": [
   "scale"
  ],
  "kind": "observed",
  "experiments": [
   "saffire-1-1",
   "saffire-1-2"
  ],
  "pdf_page": 26
 },
 {
  "id": "saffire-steady-wide-flame",
  "source_id": "saffire-1-3",
  "in": "pdf",
  "quote": "Unlike 1-g, the results revealed that a steady flame could be achieved even for a wide sample burning in concurrent-flow.",
  "topics": [
   "scale",
   "airflow"
  ],
  "kind": "observed",
  "experiments": [
   "saffire-1-1"
  ],
  "pdf_page": 26
 },
 {
  "id": "saffire-confined-slower",
  "source_id": "saffire-1-3",
  "in": "pdf",
  "quote": "The flames spread more slowly than prior tests in smaller ducts. This behavior of the flame demonstrated the importance of confined spaces for potential spacecraft fires.",
  "topics": [
   "confinement",
   "scale"
  ],
  "kind": "interpretation",
  "experiments": [
   "saffire-1-1"
  ],
  "pdf_page": 26
 },
 {
  "id": "saffire-silicone-reduced",
  "source_id": "saffire-1-3",
  "in": "pdf",
  "quote": "Flammability of silicone in microgravity appears to be reduced compared to normal gravity, at least for the flow speeds tested.",
  "topics": [
   "materials-screening"
  ],
  "kind": "interpretation",
  "experiments": [
   "saffire-2-1",
   "saffire-2-2",
   "saffire-2-3",
   "saffire-2-4"
  ],
  "pdf_page": 26
 },
 {
  "id": "saffire-nomex-not-ignited",
  "source_id": "saffire-1-3",
  "in": "pdf",
  "quote": "Despite this significant heating load, the fabric was not ignited.",
  "topics": [
   "materials-screening"
  ],
  "kind": "observed",
  "experiments": [
   "saffire-2-7"
  ],
  "pdf_page": 25
 },
 {
  "id": "saffire-quiescent-extinguishment",
  "source_id": "saffire-4-5",
  "in": "pdf",
  "quote": "Extinguishment of thin charring fuels at increased oxygen cannot be assumed to occur rapidly in quiescent conditions.",
  "topics": [
   "suppression",
   "oxygen",
   "airflow"
  ],
  "kind": "interpretation",
  "experiments": [
   "saffire-v-2"
  ],
  "pdf_page": 7
 },
 {
  "id": "saffire-thick-fuel-pinned",
  "source_id": "saffire-4-5",
  "in": "pdf",
  "quote": "Flames on thick fuels in concurrent flow did not spread and were instead pinned to the leading edge of the sample",
  "topics": [
   "geometry"
  ],
  "kind": "observed",
  "pdf_page": 13
 },
 {
  "id": "saffire-flame-jumped-gap",
  "source_id": "saffire-4-5",
  "in": "pdf",
  "quote": "In one case, a flame was seen to jump a 4.5 cm gap to ignite a previously warmed PMMA surface.",
  "topics": [
   "scale"
  ],
  "kind": "observed",
  "pdf_page": 13
 },
 {
  "id": "saffire-smoke-main-hazard",
  "source_id": "saffire-6",
  "in": "pdf",
  "quote": "Collectively these results demonstrate that the human hazard from a fire in a spacecraft is very similar to terrestrial fires where the heat from the fire is not the principal hazard and rather the smoke and gaseous products are a much greater concern.",
  "topics": [
   "smoke",
   "detection"
  ],
  "kind": "interpretation",
  "experiments": [
   "saffire-iv-1",
   "saffire-v-2",
   "saffire-vi-2",
   "saffire-vi-3",
   "saffire-vi-4"
  ],
  "pdf_page": 6
 },
 {
  "id": "saffire-alarm-981-s",
  "source_id": "saffire-6",
  "in": "pdf",
  "quote": "The smoke from the fire event was readily detected by an ionization detector and a light scattering system but a typical alarm threshold was only achieved at 981 seconds.",
  "topics": [
   "detection",
   "smoke"
  ],
  "kind": "observed",
  "pdf_page": 6
 },
 {
  "id": "saffire-co-co2-limits",
  "source_id": "saffire-6",
  "in": "pdf",
  "quote": "However, the ambient concentrations of carbon monoxide and carbon dioxide rose significantly with the PMMA tests exceeding the 1-hour carbon dioxide limit and the 24-hour carbon monoxide limit.",
  "topics": [
   "smoke"
  ],
  "kind": "observed",
  "experiments": [
   "saffire-vi-3",
   "saffire-vi-4"
  ],
  "pdf_page": 6
 },
 {
  "id": "saffire-partial-g-needed",
  "source_id": "saffire-6",
  "in": "pdf",
  "quote": "Further work will be needed to extend these results to the partial gravity environment expected on future mission to the moon and Mars.",
  "topics": [
   "partial-gravity"
  ],
  "kind": "interpretation",
  "pdf_page": 6
 },
 {
  "id": "saffire-practical-scale-kw",
  "source_id": "saffire-6",
  "in": "pdf",
  "quote": "Practical scale fires ranging from 1.5 to 3.2 kW were tested in unmanned spacecraft with free air volumes of 17 to 19 cubic meters.",
  "topics": [
   "scale"
  ],
  "kind": "observed",
  "experiments": [
   "saffire-iv-1",
   "saffire-v-2",
   "saffire-vi-2",
   "saffire-vi-3",
   "saffire-vi-4"
  ],
  "pdf_page": 6
 },
 {
  "id": "flex-loi-objective",
  "source_id": "flex",
  "in": "pdf",
  "quote": "A principle objective was to determine the limiting oxygen index (LOI), the oxygen percentage below which combustion would not occur.",
  "topics": [
   "oxygen",
   "droplet"
  ],
  "kind": "context",
  "pdf_page": 8
 },
 {
  "id": "flex-loi-lower",
  "source_id": "flex",
  "in": "pdf",
  "quote": "Observed LOI values for these fuels appear to be slightly lower than initially expected.",
  "topics": [
   "oxygen",
   "droplet"
  ],
  "kind": "observed",
  "pdf_page": 8
 },
 {
  "id": "flex-test-conditions",
  "source_id": "flex",
  "in": "pdf",
  "quote": "The droplets had initial diameters between 2 and 5 mm, and they were burned in oxidizing atmospheres at ambient temperature and various pressures between 0.70 and 3.05 atm, over ranges of dilution of oxygen with nitrogen, with carbon dioxide, and with mixtures thereof.",
  "topics": [
   "droplet",
   "pressure",
   "suppression"
  ],
  "kind": "observed",
  "pdf_page": 8
 },
 {
  "id": "sofie-lower-o2-reduced-g",
  "source_id": "sofie",
  "in": "pdf",
  "quote": "In reduced gravity (0g, Lunar g, Martian g), a flame can be sustained at lower O2.",
  "topics": [
   "partial-gravity",
   "oxygen",
   "materials-screening"
  ],
  "kind": "context",
  "pdf_page": 6
 },
 {
  "id": "sofie-exploration-atmosphere",
  "source_id": "sofie",
  "in": "pdf",
  "quote": "Thin fuel sheets: few materials rated even in 1g at 34% O2, 8.2 psia (exploration atmosphere).",
  "topics": [
   "pressure",
   "oxygen",
   "materials-screening"
  ],
  "kind": "context",
  "pdf_page": 6
 },
 {
  "id": "sofie-exploration-testing",
  "source_id": "sofie",
  "in": "abstract",
  "quote": "The CIR chamber provides a level of containment and permits testing at variable oxygen concentrations and pressures representative of current and planned NASA Space Exploration Atmospheres.",
  "topics": [
   "pressure",
   "oxygen"
  ],
  "kind": "context"
 },
 {
  "id": "acme-spherical-flames",
  "source_id": "acme",
  "in": "abstract",
  "quote": "The microgravity environment avoids buoyancy-induced flicker and enables the creation of spherical flames, allowing numerical models to focus computational power on transport phenomena and chemical kinetics.",
  "topics": [
   "gas-flame"
  ],
  "kind": "observed"
 },
 {
  "id": "acme-secondary-objective",
  "source_id": "acme",
  "in": "abstract",
  "quote": "The research is primarily focused on improving practical terrestrial combustion through fundamental microgravity research, where a secondary objective is spacecraft fire safety.",
  "topics": [
   "gas-flame"
  ],
  "kind": "context"
 }
]