Flame propagation experiments on the ISS
Experiments on the ISS will show how quickly fire can spread on spacecraft and what implications this will have for future space missions. The research is carried out by scientists from ZARM and the Gifu University in Japan.
Experiments on fire safety are currently taking place on the ISS
How does fire behave in weightlessness, and what implications does this have for future space missions in orbit around the Earth, to the Moon or even Mars? A research team from the Center of Applied Space Technology and Microgravity (ZARM) at the University of Bremen and Gifu University in Japan, in cooperation with the Japanese Space Agency JAXA and the German Space Agency at DLR, is investigating precisely these questions. In a series of complex experiments aboard the International Space Station (ISS), the scientists are examining the flammability of materials under reduced gravity and various atmospheric conditions. This data will help us to better understand how fire spreads in microgravity, thus improving the safety of astronauts.
A total of eight experiments are currently being carried out on the ISS to investigate how fires spread along differently structured material samples in microgravity. The researchers are particularly interested in how quickly flames spread in relation to the oxygen concentration in the ambient air — and there is a very pragmatic reason for this. For future crewed space missions, it is planned to lower the air pressure on board. This has two advantages: Extravehicular activities (EVAs) can be prepared more quickly, and spacecraft can be built with a lower mass – which saves costs and fuel. However, at lower pressure, the oxygen content in the breathing air must increase so that the astronauts can still absorb enough oxygen – from currently around 21% to up to 35%. This considerably increases the risk of fire.
Under increased oxygen concentrations, materials that are not considered flammable on Earth can catch fire in zero gravity. In addition, fires spread much faster. The researchers have already gained these insights through weightlessness experiments in the Bremen Drop Tower. The current experiments on the ISS are providing further valuable — and realistic — data to improve our understanding of flame propagation mechanisms and to develop methods to prevent fires. Compared to the Drop Tower, the ISS offers significantly longer test times, enabling thicker material samples to be examined. “These experiments are essential for realistically assessing the risk of future crewed space missions,” says project manager Florian Meyer.
