In 2022, China grew rice from seed to seed on Tiangong for 120 days; six seeds produced 59, and their descendants reached a third generation on Earth

Chinese astronauts once brought back something strange from space: the world's first rice seeds ever grown from seed to seed in orbit, according to the Chinese Academy of Sciences. In 2022, six rice seeds spent 120 days aboard the Tiangong space station. By the end, those six ended up becoming 59. Years later, their descendants produced a third generation on Earth.

A small lab, a big goal

The rice seeds traveled aboard the Wentian lab module, which launched and docked with China's Tiangong space station in July 2022. The rice-growing experiment itself began a few days later, on July 29. Once in orbit, the caretaking duties were taken over by the crew of the Shenzhou-14, astronauts Chen Dong, Liu Yang and Cai Xuzhe. They aimed to direct the seeds through the complete life cycle of rice: germination, growth, flowering and finally new seeds. And as the Chinese Academy of Sciences report notes, only a few plants, including thale cress, rapeseed, peas and wheat, ever completed a full life cycle in space before. Rice, the food of billions of people, had never made that list.


120 days, no gravity to guide it

The experiment began on 29 July 2022 and lasted for 120 days. On Earth, gravity tells a plant which way is down and which way is up. That signal isn’t there in orbit, so it’s not easy to grow rice in those conditions. The module's space was tight and the whole environment artificial, making it difficult to complete the crop's full cycle, Zheng Huiqiong, a researcher at the Center for Excellence in Molecular Plant Sciences, told Space.com. But the plants lived on. By the time the astronauts returned to Earth in December 2022, the original six seeds had grown to 59.

Back on Earth, three generations deep

The CAS report says the new seeds, along with other biological samples, were sent to a CAS research center in Beijing and then transferred to labs in Shanghai. From there, scientists wanted to see if the rice grown in space could continue to reproduce normally under normal gravity. Researchers planted a batch in an artificial climate room, the second generation, by Zheng's count, with the space-grown seeds counted as the first, and it produced some 10,000 new seeds. A portion of those were then planted outdoors in open farm fields as a third generation, which Xinhua reported matured normally after more than 100 days. "The research findings demonstrate that the seeds grown in space can still reproduce on Earth," Zheng told the news agency, calling it proof that food production in space is possible.

Sweeter, thinner, and a little different

Space clearly left its mark on the rice. The space-bred seeds had about five to six times as much glucose and fructose as common rice, and slightly more protein, so the grain may taste sweeter and have more energy, Xinhua’s report said. But the plants weren't without their quirks. They produced fewer leaves than normal, making it hard to plant them densely, added the CAS report. The space rice also bloomed a little earlier than its Earth counterpart. Its stems were also looser; the dwarf variety became shorter, while the tall variety remained roughly the same height.

Why this small crop is a big deal

More than half of the world's population depends on rice, so successfully cultivating it in space is a big deal. Until this experiment, only smaller, hardier plants had been able to complete a full life cycle, from seed to seed, off-planet. Zheng and her CAS colleagues have framed the result as a step toward understanding whether astronauts could grow more of their own food on long missions instead of hauling every meal from Earth. It's a small module, six seeds, and 120 days that quietly opened the door to something much bigger: the idea that a staple crop for humanity on Earth could one day also feed humanity in space.