The world first satellite for Lidar carbon monitoring: CZ-4C launch vehicle successfully launched the satellite for atmospheric environmental monitoring

At 2:16 on April 16, 2022, CZ-4C Yao-28 launch vehicle was launched at Taiyuan Satellite Launch Center, successfully sending the satellite for atmospheric environmental monitoring into the target orbit.

The launch task was a complete success.

Both the satellite and the launch vehicle are developed by Shanghai Academy of Spaceflight Technology.

The satellite for atmospheric environmental monitoring is the world first satellite capable of Lidar detection of CO₂. It can considerably increase the carbon monitoring and air monitoring ability in the world. After the satellite is sent into the target orbit, the quantitative remote sensing service ability in the fields of natural environment, meteorology and agriculture will achieve leapfrog improvement. 

The satellite for atmospheric environmental monitoring is designed to work in a sun-synchronous orbit of 705km. The launch weight of the whole satellite is about 2.6t. Loaded with five remote sensing instruments, i.e., atmospheric sounding Lidar, high-precision polarization scanner, multi-angle polarization imager, ultraviolet hyperspectral atmospheric composition detector, and wide-range imaging spectrometer, it is a multi-element comprehensive monitoring satellite for active CO₂ laser detection, 3D detection of fine particles, gaseous pollutant detection and surface environment detection. 

The satellite for atmospheric environmental monitoring ranks 1^st in the world in three aspects, namely, CO₂ detection methods and accuracy, active and passive detection of fine particles and polarization crossfire detection. 

Extraordinary effect of Lidar in carbon dioxide detection

The satellite for atmospheric environmental monitoring achieves the active, high-precision, all-day, and global Lidar detection of CO₂ for the first time in the world. Its detection accuracy has been greatly improved and is higher than 1ppm, reaching the world highest level. It can provide the most accurate remote sensing data for China to achieve the goals of carbon peaking and carbon neutrality. Besides, through the layered “CT” scanning of atmosphere, the atmospheric sounding Lidar is the first in China to obtain the vertical distribution information about aerosol in the world, including its optical thickness, shape and size. 

Innovative comprehensive means for PM2.5 monitoring

The satellite for atmospheric environmental monitoring is the first to adopt the comprehensive detection system combining active and passive detection through multiple means in the world. Through different types of loads with different principles, it can combine the echo signal received by the active laser and the reflected sunlight signal received passively, and realize the high-precision monitoring of the concentration of near-ground fine particles (PM2.5 etc.) through comprehensive inversion of various remote sensing data to provide scientific data support for the precise prevention and control of air pollution.

High information integration efficiency through polarization crossfire

The satellite for atmospheric environmental monitoring adopts the integrated and inverted polarization crossfire detection technology for the first time in the world and can obtain various parameters of aerosol, such as the optical thickness and particle size. Through integration of spatial information, radiation and polarization dimensions, it can greatly improve the fine particle detection accuracy. The technology has reached an advanced level in the world. Besides, the ultraviolet hyperspectral atmospheric composition detector and wide-range imaging spectrometer will also greatly improve the ability for monitoring the gaseous pollutants and ground surface environment. The spatial resolution of hyperspectral atmospheric observation in the ultraviolet spectrum and wide-range multispectral observation has been doubled. 

The successful launch and in-orbit application of the satellite for atmospheric environmental monitoring symbolizes that China has reached the world leading level in the field of atmospheric remote sensing. It will provide powerful support for us to synergize the reduction of pollution and carbon emissions and build a beautiful China. During the 14^th Five-year Plan period, China will also launch a high-precision satellite for comprehensive greenhouse gas detection, which will be networked with the satellite for atmospheric environmental monitoring for observations. This can further improve China’s space-based carbon monitoring capability and level, and will make contribution to the ecological progress and realization of the goals of carbon peaking and carbon neutrality in China.

CZ-4C launch vehicle, which undertakes the launch task, is a normal temperature, liquid, three-stage launch vehicle with excellent performance and wide uses. CZ-4 launch vehicles have flexible launch programs for different types of satellites. It has the ability for launching various types of satellites for different orbits, and one launch vehicle can realize the launch of one or more satellites. Its carrying capacity in the sun-synchronous circular orbit can reach 3t (with an orbital height of 700km).

This is the first time in this year for CZ-4 launch vehicles to carry out the launch task in Taiyuan Satellite Launch Center. Under the situation of high-density launches, the test members need to assemble in Shanghai, Jiuquan, and Taiyuan respectively. The serious COVID situation has also caused great difficulties for the test members to gather. Under the strong leadership of China Aerospace Science and Technology Corporation and Shanghai Academy of Spaceflight Technology, active and meticulous measures have been taken. The test members from Shanghai were under closed-off management one week in advance. After more than 90 hours on the product train, they finally arrived at Taiyuan Satellite Launch Center successfully. Some team members took a bus for more than 30 hours after completing the last task in Jiuquan Satellite Launch Center and finally arrived at the destination. Others are the team members who stayed for this task after completing the maiden flight task of Long March 6 Gai launch vehicle at Taiyuan Satellite Launch Center. The test members strived to overcome all difficulties, and the co-workers in Shanghai provided a powerful guarantee despite the epidemic. The team members in Jiuquan Satellite Launch Center also worked hard together. They worked hand in hand and built the image of aerospace science and technology in China jointly. In order to ensure that the test members have no worries behind, Shanghai Academy of Spaceflight Technology actively understood the difficulties of team members, and sent daily necessities to them, so that the team members and their families can be relieved. The completely successful launch of CZ-4C Yao-28 launch vehicle with the effort of all members has been a strong boost and great cheer for Shanghai! 

The unified WRP002 ground test, launch and control equipment adopted by the launch vehicle this time is firstly used in Taiyuan Satellite Launch Center. Before entrance to the site, the equipment has been subject to multiple assessments and verifications. The model planning is made in advance. Group personnel are sent to the site in advance for equipment erection and restoration. Six tightened inspections are carried out. Strict assessments were performed to the equipment and system, general test and launching site, which finally guaranteed the perfect performance of the task. So far, Shanghai Academy of Spaceflight Technology has achieved the integration of miniaturization, automation and unattended operation of the test, launch and control system, which can provide a better guarantee for the ground test and launch tasks in the future. 

In order to ensure the success of the task, we have established special coronavirus prevention and control measures, strictly implemented the epidemic prevention requirements of the local government and launch site, and taken protective measures actively. In the task, we have implemented the management measures including confirmation-based planning, digital management system, regular meetings for daily clearing and closed-loop implementation of to-do items, strengthened the quality validation and refined process control at the launching site, and grasped all details in the work at the launching site. Meanwhile, we have also upgraded the digital management system continually to further improve the completeness, fineness and efficiency of work. 

This launch task is the 90^th launch task of CZ-4 launch vehicles, the 157^th launch task of the Long March launch vehicles developed by Shanghai Academy of Spaceflight Technology, as well as the 416^th launch task of Long March launch vehicles.