NASA Studies Fire in Microgravity

While setting a fire in space sounds like a bad idea, scientists have been safely creating controlled flames in space for decades. These experiments, many of which are sponsored by NASA’s Biological and Physical Sciences (BPS) Division, are improving our understanding of combustion and the safety of future deep space explorers.

What causes flames to behave differently in space? When you remove Earth’s gravitational pull, flames behave much differently. The typical shape of a candle flame is caused by less dense warm air rising to be replaced by cooler ambient air from below. In microgravity, however, that circulation effect does not happen, creating a spherical flame!

Why study flames in space? Gravity is a strong force that can cloud scientific studies on Earth. Studying combustion in microgravity provides a unique opportunity for scientists to better understand the fundamental aspects of combustion without that clouding effect of gravity.

Additionally, researchers study fire in space to better protect astronauts. Astronauts must know what to expect in case of a fire emergency. Unlike on Earth, Astronauts cannot leave the spacecraft and dial 911. The spacecraft environment must be made as safe as possible by using materials that do not burn whenever possible. Some materials may even be more flammable in partial-gravity environments, making this research crucial.

How to study fire in microgravity? Researchers have designed International Space Station facilities to study combustion while keeping crew safe during the tests. The primary facility used to study flames aboard station is the Combustion Integrated Rack (CIR). CIR safely contains small-scale flame studies and requires little crew interaction.

The BPS-sponsored Solid Fuel Ignition and Extinction (SoFIE) experiment is designed to slot into the CIR and enables studies of ignition and the flammability of solid spacecraft materials.

Larger scale flame studies have been conducted aboard Northrop Grumman Cygnus spacecraft after they depart station. This Saffire series of experiments allowed for scaled-up studies of fire spread.

For more information, visit Combusion Science.