Space is the only place where rocket fuel could be more precious than water. The China Manned Space Agency announced last month that taikonauts on the ongoing Shenzhou-19 mission successfully produced oxygen and ethylene, a key ingredient for rocket fuel. The process was the first-ever in-orbit demonstration of artificial photosynthesis technology.
The process uses physical and chemical methods to mimic the natural photosynthesis that plants use to survive, according to the South China Morning Post. The space agency uniquely used semiconductor catalysts to provoke a photochemical within a drawer-shaped device onboard the Tiangong space station. Futurism explained why this development could be revolutionary:
The idea of using semiconductor catalysts differs from other conventional oxygen-producing techniques, such as electrolysis on board the International Space Station, which is used to turn solar energy into a supply of breathable air.
Experts have generally found that electrolysis is too energy intensive for long-distance space travel. By using semiconductor catalysts instead, Chinese researchers hope to convert carbon dioxide at both room temperature and standard atmospheric pressure, thereby requiring far less energy.
It should be noted that oxygen on the International Space Station must still be replenished through resupply missions to meet demand. NASA has experimented with artificial photosynthesis to investigate how plants grow in microgravity, not prolong spaceflight. With the ISS’s death in sight, NASA and Roscomsos are spending more resources to keep the station running until it’s sent on a one-way trip to the bottom of the Pacific Ocean.
While China’s space agency only confirmed that the artificial photosynthesis process was successful, it didn’t publicly state how much oxygen and ethylene were produced in its experiments. The effectiveness of semiconductor catalysts will determine whether they are used in regular operations and whether other agencies develop similar systems. With the United States and China attempting to conduct crewed missions to the Moon over the next decade, resource management will be critical for both programs.