Behind WeChat’s new loading photo is a story of China’s self-reliance in space technology

The loading page on the right uses a photo taken by the Fengyun-4A satellite

China’s popular mobile messaging app WeChat got a new loading page on Sept. 25, a satellite photo of the Earth showing Chinese territory. The photo was taken by the Fengyun-4A satellite, the first of China’s second-generation geostationary orbiting weather satellites. The previous photo was taken by a US satellite.

Why the change?

The move was aimed at commemorating the operation of the Fengyun-4A satellite, which took place on Sept. 25, said the State Administration of Science, Technology, and Industry for National Defense (SASTIND).

The satellite has helped improve the country’s weather and climate forecasts. For instance, it was used to serve the Belt and Road Forum for International Cooperation held in Beijing in May.

Its successful operation allows China to become a leader in developing geostationary orbiting weather satellites, the SASTIND said in a statement.

China has eight weather satellites working in orbit. The Fengyun satellites are providing 81 countries and regions with effective weather data and have been widely used for weather forecast, disaster prevention, damage reduction, and scientific research.

The team that developed the hyper-spectral vertical atmospheric sounding payload

Three firsts in the world

The satellite was launched from the Xichang Satellite Launch Center in southwest China’s Sichuan province on December 11, 2016. It has achieved three firsts in the world. For example, it was the first to carry a hyper-spectral vertical atmospheric sounding payload, which could conduct a high-precision observation of atmosphere over China and neighborhoods.

It was also the first satellite in the world to carry radiometers, detecting instruments, and lightning instruments, as well as the first to use stationary orbit microwave detection in the frequency band of 425GHz.

The Fengyun-4A satellite is the first in China that can capture lightning, because of its onboard lightning mapping imager. The instrument can detect lightning over China and neighboring areas and take 500 pictures per second, scientists say.

By the end of 2017, the satellite will be an important player in the World Meteorological Organization Integrated Global Observing System, and make greater contribution to regional disaster prevention and risk reduction, according to a report

Fifteen years of hard work drives technological upgrades of domestic enterprises

Scientists at the Shanghai Academy of Spaceflight Technology spent 15 years on the development of the Fengyun-4A satellite. Over the past 15 years, the project has driven the technological upgrades of many private enterprises.

Fengyun-4 satellite (file photo)

Now, data sent back by the satellite is eagerly wanted by international meteorological organizations, because it can only be detected by the Chinese satellite.

“Data delivered by the satellite enables mankind to see, for instance, how cold air above the Qinghai-Tibet Plateau moves down and flows eastward to raise the hot air there, a process which used to be based mostly on theoretical speculation,” said Ding Lei, deputy director of the Shanghai Institute of Technical Physics of the Chinese Academy of Sciences, who is also the chief designer of the Fengyun-4A’s detecting instrument.

Europe and the US have worked hard toward the goal only to suspend or change their plans due to technical challenges and high costs.

The satellite project has encountered a lot of difficulties. Some parts of the satellite were not produced domestically, so scientists had to work with foreign manufacturers, but they either refused to cooperate with or declined to sell their products to China.

For instance, it was not until 2009 that scientists found a domestic factory that could produce aluminum silicon carbide, a light but very hard material that was used to build the structure of the satellite. Now the technology is widely applied in the industry.

Other key parts of the satellite, such as woven carbon fiber composite, special test equipment, and long-life and high-performance grease, were also manufactured by Chinese enterprises.