How to extinguish a fire in space.

The U.S. National Aeronautics and Space Administration (NASA) is conducting a series of experiments on the space station to learn how to extinguish fires in space.

Flames in space burn at lower temperatures, more slowly, and with less oxygen than in a normal gravitational environment. Photo: NASA

According to Discovery, a fire breaking out inside a crewed spacecraft would cause panic. Putting out a fire on board is not simply a matter of grabbing the nearest fire extinguisher and spraying it on the flames.

Flames behave very differently in zero gravity or low gravity environments. On Earth, upward currents of hot air pull flammable materials away from the flame and draw oxygen toward themselves. This is why the flame of a candle looks like a teardrop.

"In space, a fire burns in all directions like a ball, making it difficult for astronauts to pinpoint the source of the fire. If you have a smoke detector on Earth, it's usually placed on the ceiling because the smoke rises. But in a zero-gravity environment, the smoke spreads in all directions," said Daniel Dietrich, an expert at NASA's Glenn Research Center.

When astronauts prepare to leave Earth's orbit, they need to learn how to extinguish fires in space. In 1997, a fire broke out in an oxygen tank on the Russian Mir spacecraft, forcing those nearby to evacuate. The fire burned for 14 minutes before running out of fuel.

Fires in space burn at lower temperatures, more slowly, and with less oxygen than in a normal gravity environment. This means that the materials used to extinguish the fire must be highly concentrated. Astronauts on the International Space Station (ISS) regularly practice fire safety, using CO2 fire extinguishers.

Dietrich and Forman Williams of the University of California San Diego, USA, are conducting the Flame Extinguishing Experiment 2 (FLEX2) program on the ISS. The goal of this program is to find better fire-extinguishing equipment for use in outer space, making space travel safer.

"Experiments conducted in Earth orbit will help develop the fundamental knowledge needed to design space travel," Williams said.

The first FLEX experiments took place from 2009 to 2014. In the FLEX2 program, the research team conducted experiments inside the Destiny science module (a unit containing the equipment rack for science projects) using remote control. They lit small flames and observed how they burned at different concentrations of surrounding gases.

The results showed that two common spacecraft fuels, methanol and heptanes, will burn when there is at least 12-13% oxygen concentration in the spacecraft. Meanwhile, humans need a minimum of about 14-15% oxygen to survive.

Knowing exactly when a fire goes out will help engineers create better fire-fighting equipment, and allow astronauts to make more accurate decisions if a disaster occurs, including altering the gas mixture inside the module to extinguish the fire.

According to VnExpress