China’s Shenzhou 16 astronauts conducted an eye-raising experiment in space involving naked flames aboard the Tiangong space station.
Astronauts Gui Haichao and Zhu Yangzhu lit a candle during a live lecture broadcast from China’s Tiangong space station on Sept. 21 to display how flames burn in microgravity. Strikingly, the flames appear nearly spherical, reasonably than the teardrop-shaped flames we’re accustomed to back on Earth.
Lit candles on Earth produce flames shaped through buoyancy-driven convection, with hot air rising and cold air descending. That combustion convection current is weak within the microgravity environment of low Earth orbit, nevertheless. This implies flames diffuse in all directions, leading to spherical fireballs.
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The livestreamed lecture was the fourth so-called “Tiangong classroom” hosted on China’s space station. The astronauts interacted with students in five classrooms across China, demonstrating a lot of microgravity phenomena. As with previous classrooms, the astronauts demonstrated that many physical processes behave in a different way than they do on Earth.
Nonetheless the candle experiment — through which Gui strikes a match to provide a unadorned flame to light the candle — would likely be met by surprise by International Space Station participants, who’ve strict rules regarding flammable materials and naked flames.
I made this – that point ESA astronaut @Astro_Alex made Mission Control think he might need snuck an actual candle onto @Space_Station. It’s amazing what you possibly can do with an old penlight and a few spare metallic tape: https://t.co/5UvfA1kC8j pic.twitter.com/TFlHX42YOpMarch 9, 2021
Strict fire safety measures aboard the ISS are partly a response to a big fire on the Russian space station Mir in in 1997.
Combustion in microgravity has been the topic of quite a few experiments on the ISS, but often using a specially-designed combustion integrated rack, keeping fire isolated and contained.
Tiangong also has its Combustion Experiment Rack (CER) for serious research on this area.