Chinese astronauts pull off one stunt no American crew is allowed to do on the ISS — and it's all on tape
Chinese astronauts at the Tiangong Space Station carried out a task that American astronauts are usually strictly prohibited from doing—and they even shot a video of the entire experiment, which deeply worried people back home on Earth. They lit a match stick on September 21, 2023, turning a blind eye to fire safety protocols. However, the experiment revealed something unusual — how flames react differently in microgravity.
When astronauts Gui Haichao and Zhu Yangzhu lit a candle, the flames formed almost perfect spheres in contrast to the teardrop-shaped ones we see on Earth, as reported by Space. The flames expanded in all directions, generating a fireball-like structure. This happened because the absence of gravity prohibited the hot air from rising upwards, enabling the flames to burn horizontally. The color of the flame also reportedly kept changing based on the temperature, as reported by KNews. The live-streamed lecture marked the fourth session of the 'Tiangong Classroom' series, broadcast from China’s space station.
As the video made the rounds on social media platforms, it prompted a flurry of reactions. On YouTube, a person who goes by the username @ChimkenRiceNuggy shared, “Since there is no up and down from space. The flame went in every direction, which formed a spherical shape. That is crazy to know.” Another person, @Apprentice_life, remarked, “Amazing and awesome to see. Thank you for taking the risk to light a naked flame in such an environment.”
As the comments poured in, a netizen @oubliette31415 noted, “An open flame seems a bit risky in an oxygen-rich environment, but what do I know. No doubt, our Chinese cosmonauts are the definition of professional and absolutely know what they are doing at all times.” Similarly, @icebluscorpion gushed, “I love that they do such things without safety regards. Such experiments are made in a chamber nowadays. I think they either didn't hear about the tragic fire incidents in space capsules of the NASA missions, or they just don't give a sh-t about safety at all. They will play with fire until they become roasted. Space ducks up there, I assume.”
Researchers at the International Space Station have also conducted several studies to examine the actions of fire in microgravity, but they have always done it in very controlled chambers. The Combustion Integrated Rack, a unique combustion chamber intended to safely control any flames, is used for these experiments. According to research by ISS, fire in space can start with less oxygen but burn for a longer period than expected. This suggests that in microgravity, things that are thought to be fire-safe on Earth could also unexpectedly catch fire. Haichao and Yangzhu were surely brave—that's for sure! And their classroom series did in fact teach us something we didn't know!