BEIJING -- China's space station, with the Shenzhou XV crew now in orbit, can produce 100 percent of its oxygen supply through its onboard regeneration system, according to a space technology conference in Harbin, capital of China's northernmost Heilongjiang province.

The development reflects that fundamental transformation of the environmental control and life-support system for China's manned spacecraft from "replenishment" to "regeneration," said Bian Qiang, director of the environmental control and life-support engineering office under the Astronaut Center of China.

As a key technology for China's manned space missions, the environmental control and life-support system creates basic living conditions and builds a liveable working environment for the astronauts, thus ensuring their health and safety.

The system comprises six regeneration subsystems for the following processes: oxygen production by water electrolysis; carbon dioxide removal; harmful gas removal; urine treatment; water treatment; and water production with carbon dioxide and hydrogen.

"At present, the six systems are in stable operation, with 100 percent of the oxygen resources regenerated and 95 percent of the water resources recycled. This reduces the amount of supplies from the ground by six tonnes every year," said Bian, addressing the third national manned spaceflight environmental control and life-support technology conference on Thursday.

He noted that the technology applied in the environmental control and life-support system ranks among the best in the world.

Over the past 55 years, experts have successfully developed three generations of environmental control and life-support system for China's manned spacecraft, as well as relevant products for Shenzhou spacecraft, extra-vehicular spacesuits and the three-module space station complex, according to Bian.

He added that, since the launch of China's space station mission, experts have successively tackled many technical difficulties faced by the world, and have realized the fundamental transformation of the system from "replenishment" to "regeneration," making outstanding contributions to the construction of China's space station.

The Shenzhou XV crew sent a video specially for the conference. Commander Fei Junlong said that he felt honored to witness the transformation of the environmental control and life-support technology on the space station, compared with the Shenzhou VI mission 17 years ago. He felt good about working and living in space for more than 100 days.