China is a rival space power for the Europeans, but that does not prevent cooperation. A Franco-Chinese satellite is currently being assembled in Shanghai. It will make it possible to study gamma-ray bursts, the most powerful star explosions in our universe.
It is a highly secure site which very few outsiders are allowed to enter. When visitors move inside buildings, they are automatically followed by a guard. We are in the great suburbs of Shanghai, about thirty kilometers from Pudong International Airport, within the Chinese Academy of Microsatellite Innovation. This organization depends on the all-powerful Academy of Sciences (CAS), and it is there that China develops and manufactures most of its scientific satellites, within the framework of its space program.
The telescopes installed on the satellite
This week, the atmosphere is a little different. In one of the buildings, a team of French engineers and technicians took possession of a floor. They arrived ten days ago as part of the SVOM mission, a Franco-Chinese partnership launched in 2006 and dedicated to the observation and study of gamma-ray bursts, the most distant star explosions in our universe. On the French side, the project is supervised by the National Center for Space Studies (Cnes), with the participation of several public research laboratories. The mission plans to send a joint satellite into space. After more than ten years of work on the design of this machine, the partnership entered a crucial phase this week. The assembly of the satellite has started in the suburbs of Shanghai.
About fifteen engineers and technicians, French and Chinese, are hard at work in a huge hall of 1,500 m2. The satellite is still in pieces, with on one side the main base which will serve as a vehicle and on the other the observation instruments. “We are working on the assembly of the SVOM satellite” explains Zhang Xiaofeng, deputy director of the Chinese Academy of Microsatellite Innovation.
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“There are four different instruments that are installed on the base, including two French instruments and two Chinese instruments which will make it possible to observe scientific phenomena, with complete detection of Gamma rays. The total weight of the satellite is approaching 1,000 kg , its height is very high, almost four meters. When the satellite’s solar panels are deployed, it will reach twelve meters.”
The two French observation instruments, in particular a wide-field ECLAIRs telescope which will make it possible to locate gamma-ray bursts, were designed and manufactured in France. They arrived in Shanghai last month on a cargo plane. “This is the culmination of a nearly ten-year project, explains Bertrand Cordier, astrophysicist at CEA Paris Saclay. Initially, when we imagined this mission, we made a proposal to the French space agency to study gamma-ray bursts. It turns out that the Chinese had made a similar proposal at home. There was a political will to collaborate. We were asked to meet our Chinese colleagues to build this project together for a better knowledge of the youth of our universe.”
The partnership was not always easy due to the differences in methodologies between the French and Chinese teams, but “we managed to set up a way of working halfway between the two cultures, analyzes François Gonzalez, who supervises the mission at Cnes. We found a common path between a Western culture, where we work more by analysis and simulation, and on the side of our Chinese friends, a rather empirical culture. They have to see things, touch them to fully understand a situation.”
Seals to protect manufacturing secrets
As we have seen, French and Chinese work hand in hand during the satellite assembly operations. “All assembly process data is shared. Since some equipment is French and some is Chinese, we both need to exchange this data to compare and judge” says Li Dong, the operations manager on the Chinese side. An obvious climate of trust, even if the French do not forget that China is also a rival space power. And in this assembly hall 100% controlled by Chinese security, French engineers take a few basic precautions. “The two French observation instruments are all the same little jewels of technology, explains François Gonzalez from Cnes. We obviously have an obligation to protect our know-how and our technologies. The Chinese are not given the details of the design of our instruments. It’s sort of a black box. And the Chinese do the same. To protect all this, we put seals on the critical elements of our instruments, we monitor them. It’s all happening on good terms.”
The assembly of the Franco-Chinese satellite should be completed before the summer. After a test phase of several months, the launch is scheduled for early 2024, from the Xichang space base in Sichuan province, southwest China.
France and China assemble a joint satellite – Sébastien Berriot
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