Hardware: Combustion Integrated Rack (CIR)-Fluids and Combustion Facility (FCF), Multi-user Droplet Combustion Appartatus (MDCA) · Program: International Space Station (ISS) · Fuel phase: Liquid · DOI 10.60555/mbq8-0451
Objective
The FLEX (Flame Extinguishment Experiment) investigation aims to map the flammability limits of liquid fuels in microgravity environments, measure the effectiveness of various gaseous fire suppressants such as CO2, He, and SF6, and develop reliable predictive models for combustion limits under reduced gravity conditions. The mission seeks to validate and improve simplified models by incorporating detailed chemical reactions, heat transfer, and material movement, using both space-based data and extensive ground-based tests. Key flight experiment goals include obtaining high-resolution measurements of droplet burning rates, flame extinction behavior, heat radiation, soot levels, and temperature profiles, while systematically analyzing the effects of different ambient conditions and suppressant concentrations. These investigations are essential for advancing the fundamental understanding of combustion processes in microgravity and enhancing fire safety protocols for future space missions.
FLEX (PSI-69, Combustion Integrated Rack (CIR)-Fluids and Combustion Facility (FCF), Multi-user Droplet Combustion Appartatus (MDCA), International Space Station (ISS)). 274 test runs from NASA PSI (DOI 10.60555/mbq8-0451).
Metadata Completeness
67%
Share of key conditions (oxygen, pressure, airflow) reported in the source tables.
Representative Conditions
Median of the values reported across this investigation's test runs.
- Fuel / Material
- Methanol, n-Heptane
- Gravity
- 0 g (microgravity, ISS / Cygnus flight)
- Oxygen Concentration
- 20%
- Ambient Pressure
- 101.3 kPa
- Airflow Velocity
- Not reported
The PSI record mentions both flight and ground work; 0 g reflects its ISS / Cygnus flight metadata.
Findings summary
274 test runs recorded; 12.0–34.0 % O2 (n=274); 70.2–309.3 kPa (n=273); microgravity (0 g, ISS / Cygnus flight).
Source: NASA PSI PSI-69: PSI-69_Experimental table_FLEX.csv (psi.nasa.gov). File, sheet and row are listed per test run below.
Experiment Design: Held Constant vs Varied
What stayed fixed across test runs, what was changed, and what was measured, from the NASA test tables.
Experimental table FLEX · 274 runs · 0 held constant · 7 varied · 4 measured
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Instrument and imaging settings (2)
- Test Date
- Test GMT
Test Runs (274)
Conditions and measurements for each run. Open a run to see every value and its source row.
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