Four volunteers on Friday started a 180-day living experiment in a sealed space capsule, which will test technologies that support China's deep-space exploration projects.

The volunteers - three men and one woman - will live in a sealed capsule in Shenzhen, Guangdong province. Scientists hope the experiment will cast light on how oxygen, water and food can be used and recycled under controlled conditions.

The project has been designed to test the "controlled ecological life support system", which is inspired by technologies used on China's Shenzhou spacecraft.

The 1,340-cubic-meter capsule, which has a floor space of 370 square meters, is divided into eight compartments, including the passenger compartment, resource compartment and greenhouse compartments.

Scientists have cultivated 25 kinds of plants in the capsule, including wheat, potatoes, sweet potatoes, soybeans, peanuts, lettuce, edible amaranth and bok choy. Strawberries, cherries, tomatoes and horseradish are also on the list.

The plants are part of a larger ecological treatment system that will help regenerate oxygen and water, reducing dependency on outside supplies.

Scientists will also monitor and observe how a hermetic environment affects physiological changes, biological rhythms, sleep patterns and emotional well-being.

The Astronaut Center of China launched a call for volunteers in May last year, and selected eight people, including an alternative team, from 2,110 candidates.

Two of the volunteers are from the center.

More than a dozen Chinese and overseas institutions are involved in the experiment, including the Shenzhen-based Space Institute of Southern China and the Chinese Academy of Sciences.