At 15:00 on the 22nd, the Sino-French Astronomical Satellite (SVOM) was lifted off by the Long March-2C carrier rocket at the Xichang Satellite Launch Center, and then entered the predetermined orbit, and the launch mission was a complete success. This satellite, which embodies the efforts of Chinese and French scientists for nearly 20 years, will help mankind capture the brilliant and fleeting gamma-ray bursts produced by the universe when it was still in its "infancy". Astronomers refer to these "fireworks" as transient sources.
The most violent eruption outside of the Big Bang
As the chief scientist of the French side of the Sino-French astronomical satellite, Bertrand Kodier witnessed the successful launch of the satellite in the valley of the Xichang Satellite Launch Center. Although Kodil has been involved in many space science projects, this is the first time he has watched a rocket lift off. He had been nervous for the past few days, and now he is finally relieved, but he still faces a series of difficult scientific work.
"It's interesting that China may have been the first civilization to observe transient skies 4,000 years ago. They keep ancient records of comets, supernovae, etc. Our mission continues the work begun by the Chinese 4,000 years ago. Kodir said.
"We want to see gamma bursts from the farthest universe and the earliest ones, studying the 'infancy' and evolution of the universe. It is also hoped to discover special, rare gamma bursts, or even new types of gamma bursts. For example, gamma bursts accompanied by the generation of kilonovae have only been found in two cases so far, which is an international research hotspot. Our satellites are well suited to find it and will be of great significance for the study of stellar evolution and for answering very interesting scientific questions such as where do gold, silver, rare earths and other elements come from. Wei Jianyan, chief scientist of the Chinese side of the satellite, said.
Renderings of the Sino-French astronomical satellite. Courtesy of the French Space Agency
Gamma bursts are the most violent eruptions in the universe known except for the Big Bang, which occur in the collapse of massive stars or the merger of two compact stars in a very short time, and are regarded by scientists as extreme physics laboratories in the universe. In-depth observation and study of gamma bursts will help humanity understand several major issues in basic science.
"With gamma bursts, we can observe the early universe as well as the earliest stars. We will open a new window for detecting gamma bursts, hoping to discover new phenomena and new celestial bodies that mankind knows nothing about. Kodir said.
The satellite is equipped with four instruments, which are divided into two categories: large field of view and high-precision observation. Among them, the observation field of view of the large field of view detection instrument is about 10,000 square degrees, which is equivalent to covering a quarter of the whole day, like opening a large net to capture the unpredictable and fleeting gamma burst in the sky. Once the target is found, the satellite will automatically turn to the target and use two small field of view telescopes to carry out long-term high-precision observation.
This project has a satellite-to-ground communication network with real-time transmission capability, which can realize the joint rapid response and observation capability of space and earth. Immediately after discovering the target, the satellite sends preliminary position and time information to the ground within one minute through the satellite-to-ground link, informing the telescopes of all bands on the earth to point to the target. If scientists find interesting targets in space on the ground, they can also use China's Beidou satellite system to command the satellite to point at the target in about five minutes.
"The fastest response time for gamma burst satellites in the world is about 20 minutes, which is a big leap." Wei Jianyan said.
The cooperation brings scientific rewards to both China and France
The Sino-French astronomical satellite adopts the cooperation mode led by the Chinese side and jointly carried out the overall design, joint development, joint operation, joint analysis of scientific exploration data and publication of scientific research results led by the Chinese side. From the start of the demonstration in 2005 to the launch of the satellite in 2024, the satellite project has gone through a long period of 20 years. After several twists and turns, it was completed with the unremitting joint efforts of both sides.
"Unlike the form of cooperation on board scientific instruments, the cooperation between the two countries began at the beginning of the conceptual design of the satellite, which was the result of joint consultation and research between China and France." Wei Jianyan said that at first, scientists and engineers from the two countries had their own ideas, but through sincere exchanges between the two sides, they eventually formed a unified goal.
This international cooperation has a long development cycle, a long time for communication, and has been disrupted by uncertainties such as the international situation and the epidemic. "Although we have experienced nearly 20 years of ups and downs, our original intention has not changed." He said.
More than 100 researchers from China and France have been involved in satellite research and development for a long time. Wei Jianyan said that the two sides learn from each other and have their own strengths. Under the promotion of the project, the participants have enhanced their understanding of the culture and national conditions of the two countries, and have become staunch supporters of Sino-French friendship and cooperation.
"The cooperation brings scientific returns to the two countries, promotes breakthroughs in space technology, and strengthens the confidence of other countries to cooperate with China in space science." He said.
On the eve of the launch of the Sino-French astronomical satellite, scientists and engineers from the two countries posed for the satellite's English name, SVOM. Courtesy of the China National Space Administration
Zhang Yonghe, the Chinese project manager who was involved in the development of the satellite, said: "Among the international cooperation projects I have participated in, this project is the most in-depth and complex, it lasts for a long time, involves many people, and has in-depth cooperation. ”
Scientists from both countries initially used email to communicate, then video conferencing, and now mostly WeChat. "Gamma bursts disappear quickly after they appear, and we have to react quickly, so using WeChat is the most convenient and effective way to communicate." Cordil said.
Together, we will make greater contributions to global space science
In the field of aerospace, Sino-French cooperation has a long history. Since the signing of the cooperation agreement between the two governments in 1997, China and France have cooperated in manned spaceflight, deep space exploration, earth observation and other fields.
In October 2018, the first satellite jointly developed by China and France, the Sino-French Oceanographic Satellite, was successfully launched. In April 2023, during French President Emmanuel Macron's visit to China, China presented 1.5 grams of lunar samples for scientific use to France. In May this year, Chang'e-6 was launched aboard the French radon detector, which was the first time that China and France carried out lunar exploration cooperation and the first French space program to land on the moon.
At 15:00 on June 22, the Sino-French Astronomical Satellite (SVOM) was lifted off by the Long March-2C carrier rocket at the Xichang Satellite Launch Center. Xinhua News Agency (photo by Chen Haojie)
"China's space science has developed rapidly over the past 20 years, and cooperation with China is very important because it will allow us to complete bigger projects and do better." Cordil said.
Liu Yunfeng, deputy director of the Department of International Cooperation of the China National Space Administration, said that the successful launch of the Sino-French astronomical satellite on the 60th anniversary of the establishment of diplomatic relations between China and France is a joint contribution of China and France to global space science. This is a landmark cooperation project between the governments of the two countries, with new technology and great challenges. The two sides have long-term cooperation in the aerospace field, mutual trust, mutual help, and friendship to continue friendship, and all-round cooperation brings win-win results.
Producer: Lei Ming, Quan Xiaoshu, Wei Tiemin, Liu Chang
Reporter: Yu Fei Li Na
Editor: Yang Xiaojing
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