In 2003, college graduate Deng Xiaojun joined the Jiuquan Satellite Launch Center in Northwest China's Gobi Desert.

With his job coded 212, he felt the excitement of sending China's first astronaut Yang Liwei into space.

Eighteen years later, Deng is code zero, tasked with the high-profile job of leading the countdown to ignition for the launch of the Shenzhou-12 crewed mission.

"Code zero is not a number, but a team," said Deng, noting the team has been sharing the responsibility and excitement of China's space missions for years.

As a home port for China's space exploration, the Jiuquan Satellite Launch Center has completed major launch missions, including 12 Shenzhou series spaceships, building the most reliable and safe spaceport for Chinese astronauts.

Deep in the Badain Jaran Desert in Northwest China, lights blaze at the vehicle assembly building throughout the night. Engineers are working around the clock to prepare for China's next space mission.

Zheng Yonghuang, the launch center's chief engineer, said a crewed space mission goes through more than 10 phases, involving hundreds of thousands of parts and components from entering the launch site to blastoff.

According to Zheng, staff members enter into preparation three months before every launch, testing and checking equipment and facilities. Even for parts as small as a fuse, how long is its service life? How long has it been in use? When should it be replaced? "We need to have every answer in mind.

"When people start to cheer a successful launch, it's time for us to learn lessons for further improvements," said Zheng.

Shi Chuangfeng is in charge of hoisting the rockets with cranes. "When hoisting a rocket, we need to align and connect dozens of bolts in one go. There are no shortcuts to take. The only thing you can do is keep practicing."

Shi has his own way of training himself: hooking a welding rod onto the crane and driving the crane to insert the rod into a beer bottle. Today, Shi and his colleagues can control the crane arm to insert a chopstick and pour wine, just like using their hands. The weather team has the same birthday as the launch center. The weather on the Gobi Desert often changes rapidly, posing challenges to launch or landing missions.

During the Shenzhou-12 crew's return, it was necessary to ensure no dangerous weather such as lightning or rainstorms at the landing site. The average ground wind speed could not exceed 15 meters per second, and the high-altitude wind could not exceed 70 meters per second. The visibility had to be no less than 10 km with no precipitation.

According to the weather team, 50 days before the return, they began to analyze the land climate data, making forecasts for the expected climate on the return.

Thirty days before return, mobile weather radars were on duty at each station, and they formulated an emergency response plan for the return. Twenty days out, the weather team had consultations with local meteorological stations.

Seven days before return, they released daily forecasts for six sites related to the landing site, and consultations were held twice a day. Within 48 hours of return, the forecasts were upgraded to hourly.

On Sept 17, the team released forecasts every three hours till the three astronauts of the Shenzhou-12 mission safely returned to the Dongfeng landing site.

Deng said he watched every blastoff from the launch site for the past 18 years, from the control room to the rooftop of his home, from the Gobi Desert to a local bridge called Shenzhou.

He once left the launch team in 2014. When he returned to the job in 2017, it felt like a family reunion.

"You stand by the window and smell something familiar. That is from the rocket's first stage engine. It feels so good to reunite with my family."