On August 9, the 18th and 19th Beidou navigation satellites established intersatellite links for the first time. Subsequently, the 19th Beidou navigation satellite successfully received and transmitted the first frame of intersatellite telemetry through the intersatellite link by the 18th Beidou navigation satellite.
This is another good news after the two Beidou navigation satellites were successfully launched at the Xichang Satellite Launch Center on July 25.
The establishment of the intersatellite link marks that my country has successfully verified the core technology of autonomous operation of the global navigation satellite constellation, laying a solid foundation for the realization of the global satellite navigation system. Behind the "bridge" of the two Beidou navigation satellites, it is inseparable from the research and development of many new technologies such as intersatellite link network protocols, space phased array antennas, autonomous navigation technology, and integrated electronic subsystems.
Building a "highway" connecting satellites
If the Beidou dual satellites want to break out of Asia and go to the world, they must flexibly respond to the space environment and maintain the interconnection between satellites and the ground, and between satellites. Breaking through the autonomous operation technology of the Beidou navigation constellation has become the primary task and the biggest difficulty faced by the research and development team.
"We must take the path of autonomy and control, otherwise we cannot achieve sustainable development," said Xie Jun, chief designer of Beidou navigation satellite.
However, it is not easy to build a "highway" connecting two small satellites in the vast universe. To this end, the Fifth Academy of China Aerospace Science and Technology Corporation (hereinafter referred to as the Fifth Academy of Aerospace) has established a new autonomous operation subsystem and invested sufficient resources to focus on the intersatellite link and constellation autonomous navigation technology.
After tackling the problem, the research and development team took the lead in proposing a hybrid new system intersatellite link solution, completed the intersatellite link demand analysis and design, and formed the design of the intersatellite link network protocol and system solution with independent intellectual property rights.
At the same time, the team overcame technical difficulties such as space phased array antennas to ensure that Beidou navigation satellites can be stable and accurate in a "handshake" in the air.
Wang Ping, chief designer of Beidou navigation satellites, said: "The intersatellite link function enables communication and ranging between satellites, which greatly improves the autonomous and controllable capabilities of the navigation system."
Write a common "language" for "Beidou"
After the hardware between satellites is connected, only by achieving real-time intercommunication in software can the satellites carry out a perfect "dialogue". The "software" here refers to "autonomous navigation technology".
This technology enables navigation satellites to detach and independently carry out navigation tasks, providing users with high-precision navigation services. According to the reporter, at present, all international navigation systems are making every effort to overcome constellation autonomous navigation technology.
Since 2000, the General Department of the Fifth Academy of Aerospace has taken the lead in China to carry out research on constellation autonomous navigation technology. Ten years later, in 2010, the team undertook the key technology research work of autonomous operation of the national Beidou major project. From the design of the overall autonomous navigation plan to the design and implementation of various algorithms, it took three years to independently develop the satellite-borne autonomous navigation software.
In the view of industry insiders, the successful development of this technology allows the "Beidou Stars" to communicate flexibly and fully in a common "language", ensuring better services for global users and providing support for the higher requirements of specific domestic users.
"Super Butler" Precise Command
The "integrated electronic subsystem" that first appeared in the Beidou navigation satellite is affectionately called the "super butler" by scientific researchers. The system realizes the supervision of the healthy operation of all subsystems, and organizes and deploys forces to fully realize the autonomous management of satellites.
As early as 2010, at the beginning of the demonstration of the new generation of Beidou navigation satellite scheme, facing the technical requirements of faster, more accurate and more precise, the designers of the Fifth Academy of Aerospace fully optimized the satellite design scheme and started the pre-research work of the integrated electronic subsystem.
The latest "integrated electronic subsystem" has been upgraded on the basis of previous telemetry and remote control as well as autonomous energy and autonomous thermal control management. According to the relevant person in charge of the Fifth Academy of Aerospace, the "integrated electronic subsystem" undertakes tasks such as autonomous navigation algorithm, intersatellite network processing, attitude orbit control, whole satellite power distribution, whole satellite heater management and pyrotechnics management.
The subsystem optimizes the information flow and product combination of the whole satellite from the top level, reduces the interface between the whole satellite equipment, and reduces the weight by 30% compared with the digital control subsystem of the regional Beidou navigation satellite. At the same time, the "integrated electronic subsystem" meets the high requirements of the new generation of Beidou navigation satellite autonomous navigation function and intersatellite network processing function for time processing.
"The 'integrated electronic subsystem' of these two satellites has greatly improved the information integration level compared with regional navigation satellites, thereby improving the efficiency of the entire satellite," said Xie Jun
