China’s rocket wreckage landing zone control is more accurate
Fengyun-4 02 star launch site. Photo by Guo Wenbin (published by Xinhua News Agency)
On June 3, the Long March 3B carrier rocket at the Xichang Satellite Launch Center< /span>Takeoff, the Fengyun-4 02 satellite was accurately sent into the scheduled orbit, and the launch was a complete success.
Many aerospace enthusiasts have discovered that the long three-B launch vehicle launched this time has a booster that looks different from the other three-with”two bars” on the body, and on the head. There is also a”yellow hat”.
What makes this booster different? It is understood that this is the”Easter Egg” of this rocket launch-the”parachute landing zone control system” is mounted on the second booster. This system can achieve the accurate landing of the rocket sub-level wreckage, allowing the booster to return to the ground steadily.
What is parachute landing zone control? According to experts, the parachute landing zone control system is to control the rocket booster’s landing point more accurately , A way to make the landing zone of the sub-level wreckage of the launch vehicle at the inland launch site safer.
Hu Wei, deputy chief designer of the Changsanjia series launch vehicle, introduced that for each launch, the designer will calculate the landing zone of each sub-level based on the rocket’s trajectory, and carry out the safety control of the landing zone accordingly. Sometimes in order to ensure the scheduled landing zone, the rocket’s flight trajectory and timing are modified, resulting in a reduction in carrying capacity. Although the use frequency of the rocket sub-level landing zone is not high, how to reduce the scope of the landing zone as much as possible and reduce the interference to the normal production and life of the landing zone has always been the pursuit of scientific researchers.
Zhang Yipu, deputy chief designer of the Long Three A series of carrier rockets, said that the parabolic landing zone control system is installed inside the booster nose cone. After the booster separates from the rocket, it flies along an upward parabolic inertia. At the predetermined altitude, the booster parachute landing zone control system is activated, and two levels of parachute are activated. For attitude control and speed reduction, the controllable parafoil booster is finally deployed for maneuvering, and the booster is guided to a predetermined area for landing, so as to achieve precise control of the landing point of the rocket booster.
Introduced by Zhang Puzhuo, the overall designer of the umbrella control system, the technology of using parafoil to control the landing zone was mostly used in the aviation field in the past. For the rocket booster, when the attitude is unstable after separation, How to realize the separation of the safety structure, the safe opening of the umbrella, and the protection of the umbrella from damage after opening the umbrella, is quite difficult.
In this Changsan B rocket flight mission, China completed for the first time the booster landing zone control flight based on 300 square meters (the largest area in China) of the controllable parafoil, verifying that it has the ability to land The ability to reduce the area to 30%. After the booster is separated from the core stage, the continuous positioning of satellite navigation under high dynamic Highly executed various key actions. In the end, under the action of the parafoil, it flew to the target maneuver point according to the predetermined homing strategy, and the test was a complete success.
Hu Wei said that this is the heaviest rocket detachment in the world that uses parafoil control to return successfully. The test has obtained all the flight data of the landing zone control system, which is the application of subsequent parachute landing zone control technology engineering. And the improvement of the safety of the rocket wreckage landing area provides an important reference.
The success of this onboard flight, the designers broke through key technologies such as the overall design technology of parachute landing zone control, the overall design technology of large-area controllable parafoil, and the integrated navigation technology under high dynamics. The feasibility of the umbrella’s booster landing zone control technology has laid a solid foundation for the subsequent engineering application of this technology.
It is understood that the booster parachute control system used in this launch was developed by the General Design Department of Rocket Academy, and the parachute system was developed by Beijing Space Electromechanical Research Institute. In terms of the control technology of the rocket separation body landing zone, the Rocket Academy has successively broken through the first-stage grid rudder landing zone control technology and the booster parachute landing zone control technology, laying a foundation for the realization of new technologies such as sub-level controllable recovery and vertical return in the future. An important technical foundation.