"Nine satellites in five days, three rockets", what does China's recent consecutive successful launches mean?

At 6:53 on August 9, my country successfully launched the Environmental Disaster Reduction No. 2 06 satellite into space using the Long March 2C carrier rocket at the Taiyuan Satellite Launch Center. The satellite entered the planned orbit smoothly and the launch mission was a complete success. Xinhua News Agency (Photo by Lu Xing)

In the early morning of August 13, my country successfully launched the Land Exploration No. 4 01 satellite using the Long March 3B carrier rocket at the Xichang Satellite Launch Center. The satellite successfully entered the predetermined orbit and the launch mission was a complete success. This mission is another victory for the Long March series of carrier rockets after the successful launch of the Long March 2C carrier rocket on August 9. On August 10, the Ceres-1 carrier rocket carrying seven satellites including the Xiguang-1 01 satellite was successfully launched. What does "three rockets and nine satellites in five days" mean?

Each satellite is unique.

Looking back at the last three launches, China Aerospace has successfully sent nine satellites into space using three rockets. Two of them are remote sensing satellites listed in the Medium- and Long-Term Development Plan for National Civilian Space Infrastructure (2015-2025). Both were developed by the Fifth Academy of the China Aerospace Science and Technology Corporation. Each satellite is powerful and of extraordinary significance.

Take the newly launched Land Exploration Satellite 4-01 as an example. The satellite uses an L-band synthetic aperture radar (SAR) payload and can provide multiple observation modes. It is an important part of my country's space-based disaster observation system. After the satellite is put into use, it will help disaster prevention and mitigation work with its fast maneuverability and high-precision microwave imaging, and will be used in conjunction with other remote sensing satellites to further improve my country's space-based disaster monitoring system.

Another example is the Earth-based Intelligent Emergency Response Satellite No. 1, which was launched by the Ceres-1 carrier rocket. The satellite is based on artificial intelligence, has an intelligent operating system, is equipped with high-resolution array cameras, near-infrared cameras and other payloads, and uses on-board intelligent processing technology to provide remote sensing observation services for ground hot spots. In addition, the satellite is also the first case in China to apply the underlying operating system of automobiles to commercial aerospace.

Private aerospace forces continue to grow and develop

It is worth noting that in one of the recent "three consecutive victories", the carrier rocket that carried out the launch mission was developed by a private rocket company in my country. This means that in addition to the traditional aerospace "national team", "civilian forces" as an important part of China's aerospace industry are also growing and developing.

At noon on August 10, the Ceres-1 carrier rocket developed by Galaxy Power successfully launched "seven satellites in one rocket" at the Jiuquan Satellite Launch Center. This mission was the second launch of the Ceres-1 series of commercial carrier rockets within a month, the third consecutive successful launch this year, and the seventh consecutive successful launch of this type of rocket.

At present, the Ceres-1 launch vehicle has served 15 commercial satellite customers and completed the launch of 28 commercial satellites with different functions into orbit, providing development support for multiple application fields such as earth observation, meteorological monitoring, satellite Internet of Things, and popular science education.

In addition, the "Gravity-1" medium-sized carrier rocket of my country's emerging commercial aerospace company Dongfang Space is expected to carry out its first flight mission at Shandong Dongfang Spaceport in the second half of this year. The launch is planned to be launched at sea. The person in charge of the rocket development team introduced that the "Gravity-1" is positioned to meet the needs of large-scale networking of small and medium-sized satellites in low orbit. The rocket is 31.4 meters high, the fairing diameter is 4.2 meters, the takeoff weight is 400 tons, the takeoff thrust is 600 tons, the low-Earth orbit carrying capacity is 6.5 tons, and the sun-synchronous orbit carrying capacity is 4.2 tons. Once the first flight of this type of rocket is successful, it will become the world's largest solid-fuel carrier rocket.

The pursuit of success never ends

Looking at the development trend of the world's aerospace industry, aerospace is still a high-tech, high-risk, and high-investment undertaking that requires long-term efforts and continuous breakthroughs and self-transcendence.

Taking the development process of the Land Exploration No. 4 01 satellite as an example, members of the development team of the Fifth Academy of China Aerospace Science and Technology Corporation worked hard for 15 years and finally achieved a breakthrough from "zero" to "one" in the world's high-orbit synthetic aperture radar satellite.

Faced with the difficult question of "whether synthetic aperture radar can form images in high orbit", the research and development team started from the imaging mechanism, sorted out the key factors affecting imaging and analyzed them one by one.

"Think about how the older generation of astronauts got through it. Without mature experience, we started with the most primitive principles, and then gradually tried and explored a way step by step." Recalling the demonstration scene at that time, Zhang Qingjun, commander-in-chief and chief designer of the Land Exploration No. 4 01 satellite, admitted that although they were confused in the face of "a blank sheet of paper", there was always a spiritual force supporting everyone to move forward.

As the rocket with the most launches in my country, the Long March 3A series of launch vehicles has undergone a large number of launch missions. Its technical maturity and reliability are obvious to all. When carrying out the launch mission of the Land Exploration No. 4 01 satellite, the development team has not stopped the pace of optimization and improvement.

"In recent years, the Long March 3A series of launch vehicles have adopted a number of technical improvements and reliability increase measures. These improvements have also been applied to this launch mission to continue to provide users with high-quality launch services." Zhang Yunlong, overall designer of the Long March 3A series of launch vehicles, introduced that the rocket development team has carried out more than 10 optimization improvements on the rocket and ground equipment, involving conventional engines, cryogenic engines, software and other aspects, further improving the reliability of the rocket.

According to reports, in addition to completing daily launch missions, the Long March 3A series launch vehicle development team also coordinated existing human and material resources to continuously promote the "double improvement" project of carrying capacity and reliability, laying the foundation for subsequent high-density launches. At present, most of the work of the "double improvement" project of carrying capacity and reliability has been completed, and it is expected to be put into flight application in the second half of this year. (Reporters Hu Zhe and Song Chen)