In 2011, the team tested the moon rover in a remote desert in Gansu province, transporting drinking water hundreds of kilometers during their trials.

"When we were drawing up the blueprints, we were very confident," he says, but the team's confidence rose and fell as unforeseen problems arose.

He discovered an oversight in the design late in the development, when computer analysis revealed that the rover could lose contact with the Earth if its antenna was shaded by the lander.

"We were tortured for a whole month," says Jia, but his team found a way around the difficulty.

"It showed a lack of experience," he says. "For the moon rover, there were too many new problems and these problems were overlooked at first."

Before the lunar probe left the factory, Jia's superiors asked if he was confident.

He was. On behalf of his team, Jia signed a responsibility certificate, committing to the mission's success, which he framed and put on his desk.

"But even though we spare no effort to achieve success, we cannot be 100-percent sure of success," he admits.

Jia has visited schools to popularize space science among children and stimulate their interest in the universe.

His next goal is Mars: "I hope before my retirement, the Chinese people can begin exploring Mars. I hope we can send a rover, better than Yutu, to Mars."