BEIJING, Sept. 20 (Xinhua) -- China's experiment in human living for space exploration is going smoothly, halfway into the project, the Astronaut Center of China (ACC) announced Tuesday.

Four volunteers started a 180-day experiment in June in a sealed space capsule, testing technology that will be used in deep-space exploration.

The experiment examines how oxygen, water and food can be used and reused in space.

The ACC has used Mars time with 24 hours and 40 minutes in a day in the experiment since Aug. 26.

Scientists are also examining the physiological changes and emotional fluctuations brought by a hermetic environment.

A total of 25 kinds of plants in the capsule as part of a larger ecological treatment system are also growing well.

The experiment will conclude on Dec. 13.