China launches new astronomical satellite developed in cooperation with France

China on Saturday launched an astronomical satellite, the result of nearly 20 years of hard work between Chinese and French scientists, to capture gamma-ray bursts which flicker like fireworks in the farthest reaches of the universe.

The satellite, the Space-based Multi-band Variable Object Monitor (SVOM), was launched by a Long March-2C rocket from the Xichang Satellite Launch Center in southwest China's Sichuan Province, according to the China National Space Administration.

Four scientific instruments are installed on the satellite, two of which have been developed by China and two by France. The four instruments can realize a large field of view and high-precision observation.

Gamma-ray bursts, usually very short in duration, are the most violent explosive phenomena in the universe after the big bang, and they occur during the collapse of massive stars or the merging of binary compact stars. The in-depth observation of and research on gamma-ray bursts will help us understand some of science's fundamental questions, said Wei Jianyan, SVOM's Chinese principal investigator.

The main scientific objectives of SVOM include searching for and rapidly locating various gamma-ray bursts, comprehensively measuring and studying the electromagnetic radiation properties of these bursts, studying dark energy and the evolution of the universe through these bursts, and observing electromagnetic signals associated with gravitational waves, said Wei, who works at the Chinese Academy of Sciences' National Astronomical Observatories.

The Innovation Academy for Microsatellites at the Chinese Academy of Sciences is responsible for coordinating and assembling the SVOM satellite system. 

Advanced SVOM satellite to investigate gamma-ray bursts

The SVOM satellite is expected to contribute to the understanding of the origin of the universe according to its principal investigators.

Bertrand Cordier, SVOM's French principal investigator, told CGTN that the team expects to observe approximately 70 gamma-ray bursts per year.

"The gamma-ray burst is a tool to observe the early universe. We can observe maybe the first stars. And this is very interesting because this is the only way to do that," he said.

Wei said the team also hopes to discover some special and relatively rare types of gamma-ray bursts. He said the satellite could also be used to study Kilonova. 

"And very interestingly, our satellite may help us understand where some of the elements on Earth come from, for example, where gold, silver and copper come from," Wei said.

Wei also said the two countries have pooled their best people and capabilities to make the mission happen.

He cited the use of China's BeiDou Satellite system as a major progress.

"If on the ground, we detect a very interesting astronomical target, we can command our satellite to point to it within just a few minutes," Wei said. The process used to take 20 minutes, but now, using the BeiDou System, they can respond in about five minutes. "That's major progress," he said.

Bertrand Cordier, who is also involved in another mission with China that studies gamma-ray bursts, said having several missions work together can be even more meaningful for the field.

He said by having a very powerful system with many satellites, there would be more ways to work together to enhance the scientific study.

SVOM an "excellent example" of space cooperation

The SVOM satellite is the first astronomical satellite jointly developed by China and France.

The idea for SVOM was hatched in the mid-2000s. The team has gone through a lot since then, including working hard to make up for time lost from the COVID-19 pandemic.

Zhang Yonghe, SVOMs' Chinese project manager, said after the pandemic, everyone from both China and France worked to give their best together.

He said they will continue to work as one team in the future. 

The future operation of SVOM is complex, Zhang said. The Chinese and French sides have built a relatively large system for the operation stage, involving ground telescopes, optical instruments and more.

"So after launch, we continue to work to ensure that this system is good in every way; that it is complex, fast, good and has very high sensitivity," Zhang told CGTN.

Francois Gonzalez, SVOM's French project manager, also said that by now, it's "one unique team."

"We've been over difficulties together. We understand each other. I could say that the French team is a little bit Chinese. And Chinese are a little bit French," he said in an interview before the SVOM launch at the Xichang Satellite Launch Center.

The China National Space Administration had described the SVOM mission as an "exemplary" example of space cooperation.

Liu Yunfeng, deputy director general at the Department of International Cooperation at the China National Space Administration, said the SVOM satellite marks an important achievement between China and France in the field of space science. 

"It will contribute to the community of space scientists, as well as scientific research," Liu told CGTN.

"I think it's of global significance, as it lays the foundation for deeper, subsequent cooperation. And, it provides a model for cooperation in the space sector between China and the rest of the world," Liu added.

(CGTN's Liu Xun also contributed to the story.)