Jade Rabbit

Zhang Yuhua, a space engineer with the Shanghai Academy of Spaceflight Technology and deputy chief designer of the Chang'e-4 probe, had been part of China's manned space program for 18 years before she joined the lunar exploration team in 2006.

Making a lab simulation of the running of the rover on the moon was one of the big difficulties.

The researchers got volcanic ash from Northeast China's Jilin province to simulate the lunar soil. When the rover moved on the ash, it raised dust, causing irritation if inhaled or rubbed on the skin. To avoid the dust, the lab's air conditioner was turned off in the summer. The indoor temperature was over 40 C.

Zhang and her colleagues wore masks, raincoats and rain boots to do the experiments, and were drenched in sweat.

After China's first lunar rover, named Yutu, or Jade Rabbit, landed on the moon during the Chang'e-3 mission at the end of 2013, Zhang went to work every day as the moon rose.

However, Yutu suddenly stopped moving after going about 114 meters on the moon.

In the bid to revive it, Zhang felt great stress, and suffered ulcers in her mouth and a hoarse voice.

"I was thinking if China could send people to the moon at that time, I would like to be the first to go. I wanted to repair our Jade Rabbit so much," Zhang recalls.

All their efforts failed. Avoiding the same problem again became the challenge facing the team when they developed the new rover for the Chang'e-4 mission.

"We cared for Jade Rabbit like our own child. I thought it was like a silver swan standing on the desolate moon, more beautiful than anything else," Zhang says.

"Now, our second rover, Jade Rabbit-2, has landed on the far side of the moon. We hope it will realize our dream," she says.

"I have never doubted the significance of my work. I believe humans will go much farther into the universe in the next 100 years. But life is too short, and I can only do my best," Zhang says.