When humans dream of venturing farther into the cosmos, one question looms: how do we sustain life and the journey toward the stars? Aboard China’s Tiangong space station (the name means Heavenly Palace), scientists are offering a glimpse of the future. In a recent demonstration, Chinese astronauts operated a series of experiments that produced oxygen and rocket fuel in orbit, mimicking the natural process of photosynthesis.
Turning Carbon Into Oxygen and Fuel
The experiments, conducted by the Shenzhou-19 crew, utilized artificial photosynthesis—a technology that mimics how plants convert carbon dioxide and water into oxygen and glucose. In this case, astronauts used a drawer-shaped device equipped with semiconductor catalysts to convert carbon dioxide and water into oxygen and ethylene, a compound that can be processed into rocket propellant. Chinese researchers began exploring extraterrestrial artificial photosynthesis in 2015, according to SCMP.
The system operated under room temperature and normal atmospheric pressure, reducing the energy demands typically associated with high-temperature or high-pressure methods. According to the China Manned Space program, the process also demonstrated precise control over gas and liquid flows in microgravity, a feat required for future space-based chemical manufacturing.
“This technology mimics the natural photosynthesis process of green plants through engineered physical and chemical methods, utilizing carbon dioxide resources in confined spaces or extraterrestrial atmospheres to produce oxygen and carbon-based fuels,” explained a report from Chinese state broadcaster CCTV.
By tweaking the catalyst, researchers can produce other valuable compounds, such as methane or formic acid, which could serve as precursors for fuels or even sugars.
Why It Matters
Space agencies worldwide have long sought ways to sustain astronauts on deep-space missions. Currently, the International Space Station (ISS) relies on electrolysis, which uses electricity from solar panels to split water into hydrogen and oxygen. While effective, the method consumes significant amounts of energy. The ISS uses a third of its energy reserved for environmental control and life support systems to generate oxygen. By comparison, the artificial photosynthesis system tested on Tiangong requires far less energy, making it better suited for long-haul missions.
By integrating a method that works efficiently at room temperature, the Tiangong team has reduced energy requirements while also creating the building blocks for rocket fuel. This dual-purpose innovation addresses two key challenges of space travel: breathable air and propulsion.
With a crewed Moon landing planned before 2030, China is staking its claim as a leader in sustainable space technologies. For now, the stars are a little closer, thanks to a humble device aboard a space station orbiting Earth.
