Sun Hui and Li Miaomiao are a couple working on China's manned space program at Jiuquan Satellite Launch Center in northwestern China.

"We work in different departments. I am responsible for electrical measurement and my wife oversees the thrust system. Our posts are relatively important for rocket testing," said Sun.

They've worked at the launch site for nearly 10 years.

"I became the commander of our department last year. It's very different from being an operator. I need to pay a great deal of attention to many places and coordinate with many other departments," Sun said.

Both husband and wife say their jobs require extreme care. 

"I joined the manned mission in 2013 as an operator. My commander told me it's not like satellite missions, because we need to send astronauts into space. It involves the lives of the astronauts and we need to be careful with everything: every plug, every cable," said Sun.

"It's exciting, but I remind myself to be strict and careful because our attitude affects the safety of astronauts and the manned missions," Li added.

Work hours can be long sometimes.

"We sometimes work until very late. We might leave home when our child is still asleep and get home when he is asleep again," said Sun. "That makes me feel some regret."

"Today, I changed into casual dress and took our son to a rehearsal for a show on Children's Day. We prepared some gifts for him. He was very happy and thanked us," Li said.

The China Space Station is scheduled to be completed by the end of this year and the couple is busy.

"The frequency of launches is increasing, and we are optimizing it. Our job is becoming more and more intense, which means we have less time to rest. But the development of the space mission makes us happy," said Sun.

The couple witnessed the launch of Shenzhou-14 manned spacecraft in early June. Now they are preparing for the next launch.