This image sequence taken real-time aboard the International Space Station for the Residence Time Driven Flame Spread (SoFIE-RTDFS) investigation shows a sheet of clear acrylic plastic burning at higher oxygen levels and half the standard pressure of Earth’s atmosphere. From left to right the images show individual samples 1 mm thick about 1 second apart. As the fuel and the oxygen slowly diffuse into the flame, it develops a unique shape and character. The flame is mostly blue but becomes yellow when it strengthens before fading again to blue. The SoFIE-RTDFS investigation examines how fuel thickness and ambient pressure predict the spread of flames in microgravity. Resulting data could help expand modeling capabilities and contribute to crew safety on future missions.

jsc2025e000001 (1/2/2025) --- This image sequence taken real-time aboard the International Space Station for the Residence Time Driven Flame Spread (SoFIE-RTDFS) investigation shows a sheet of clear acrylic plastic burning at higher oxygen levels and half the standard pressure of Earth’s atmosphere. From left to right the images show individual samples 1 mm thick about 1 second apart. As the fuel and the oxygen slowly diffuse into the flame, it develops a unique shape and character. The flame is mostly blue but becomes yellow when it strengthens before fading again to blue. The SoFIE-RTDFS investigation examines how fuel thickness and ambient pressure predict the spread of flames in microgravity. Resulting data could help expand modeling capabilities and contribute to crew safety on future missions.