Four Chinese volunteers on Wednesday concluded their 180-day stay in a sealed space capsule in south China's Shenzhen City, testing technology intended for space exploration.
The volunteers -- three men and one woman -- were selected from 2,110 candidates after the Astronaut Center of China launched a call for volunteers in May last year. They have lived in a sealed capsule with a floor space of 370 square meters for the past 180 days.
The project shed light on the physiological effects of a hermetic environment and changes to biological rhythms.
The volunteers told Xinhua they were exhausted and had suffered both mentally and physically during the latter part of the test.
"The support and encouragement from colleagues outside motivated us to hold on," said Wu Shiwen, one of the volunteers. Two other volunteers told Xinhua they practiced Tai chi and read books to keep busy.
One of the purposes of the project was designed to test a life support system based on technology used on the Shenzhou spacecraft.
"I was the farmer in the capsule," said Luo Jie, who took care of 25 kinds of plants in five categories, including tomatoes, potatoes and wheat. Tong Feizhou, the only female volunteer, conducted physical checks on her companions, while Tang Yongkang ensured everyone had a regular bed and wake-up time.
Over the past six months, 99 percent of water, 70 percent food and all oxygen the volunteers consumed have been recycled inside the capsule.
Data has been collected on growth rates of the plants and the emotional, intellectual and physical condition of the volunteers during the experiment.
"We have reached our scheduled target," said Li Yinghui, a senior scientist with the China Manned Space Engineering project, who led the test. "The test has deepened our understanding of the life support system, and given us a basis to design tasks for the space station."
China launched manned spacecraft Shenzhou-11 this October. Two astronauts spent 30 days in Tiangong-2, China's first space lab, in preparation for putting a permanent manned space station into orbit.
The current project will accelerate China's progress into space, according to Li Qinglong, deputy director of the Astronaut Center of China.
More than a dozen Chinese and overseas institutions have been involved in the project, including the Shenzhen-based Space Institute of Southern China, the Chinese Academy of Sciences, Harbin Institute of Technology, Harvard University and the German Aerospace Center.
