BEIJING, Oct. 10 -- China's ailing moon rover Yutu has entered its 11th dormancy as the lunar night falls, with its functions degrading gracefully, its designer said Friday.

The moon rover is currently in good condition and works normally, but its control problem persists, said Yu Dengyun, deputy chief designer of China's lunar probe mission.

"Yutu has gone through freezing lunar nights under abnormal status, and its functions are gradually degrading," Yu told Xinhua at an exclusive interview.

He said that the moon rover and the lander of the Chang'e-3 lunar mission have completed their tasks very well. The rover's designed lifetime is just three months, but it has survived for over nine months.