SHENZHEN, June 17 (Xinhua) -- Four Chinese volunteers on Friday started a six-month living experiment in an enclosed space capsule, a project to support China's deep-space exploration plan.

The volunteers - three men and one woman - will be observed while they live in the controlled environment of the eight-compartment capsule in south China's Shenzhen city, according to the Astronaut Center of China.

The compartments provide the volunteers with recycled air, water and other living necessaries, and will help with environmental conditioning and organic cyclic regeneration.

The 1,340-cubic-meter capsule houses 25 kinds of plants, which will be used for sustenance.

The four volunteers will have their sleep and emotion patterns monitored to provide references for manned-space expeditions.

The center launched the call for volunteers in May last year, and selected eight people, including an alternative team, from 2,110 candidates.

Of the four volunteers entering the capsule, two have a space research background.