China's manned spacecraft has made significant breakthroughs in tracking and measuring black out areas | spacecraft | China
On the morning of June 4th, the Shenzhou-15 manned spacecraft successfully landed at the Dongfeng landing site. The stable tracking of the spacecraft during its passage through the black barrier area by scientific and technological personnel indicates that China has made significant breakthroughs in tracking and measuring the return of manned spacecraft through the black barrier area.
When the spacecraft returns to Earth, it will experience severe friction with the atmosphere, causing a sharp increase in temperature, resulting in ionization of gas molecules and materials that have been eroded on the surface of the spacecraft. These continuously generated ionized gases wrap around the spacecraft, forming a plasma sheath that absorbs, attenuates, refracts, reflects, and scatters electromagnetic waves, causing abnormal or even interrupted radio communication between the interior of the spacecraft and the outside world. This is known as the black barrier phenomenon, and this process is also known as the black barrier zone.
When a spacecraft passes through a black obstacle zone, it can only rely on radar and optical equipment for tracking and measurement. Whether it can stably track the spacecraft during this period, whether it is for tracking and guiding the spacecraft after the black obstacle, or timely predicting the landing point of the spacecraft, is extremely important. The mission range of the Dunhuang measurement and control area at the Jiuquan Satellite Launch Center covers the entire process of the spacecraft returning to and from the blackout area, and is the core force for achieving stable tracking of the spacecraft in the blackout area.
According to Zeng Qiang, the commander of the Dunhuang Measurement and Control Area, during the return of the Shenzhou-15 manned spacecraft, they determined the overall idea of "optimizing the radar tracking scheme for the black barrier area and improving the optical tracking strategy for cloudy weather". They formed a joint force in radar and optics, successfully completing the spacecraft's tracking and measurement mission in the black barrier area.
"Found target, tracking is normal!"
On the morning of June 4th, as the return module of the Shenzhou-15 spacecraft entered the blackout zone, Li Changsong, the leader of the optical team in the Dunhuang measurement and control area, accurately captured the real-time high-definition image of the return module and transmitted it to the Beijing Flight Control Center through onboard communication equipment in the first time.
"Starting from the Shenzhou-1 mission, in order to solve the problem of tracking and measuring the spacecraft in the blackout area, generations of measurement and control personnel have continued to tackle the problem, collaborating with multiple scientific research institutions to continuously improve targeted signal detection and tracking techniques based on the radar echo signal characteristics of the spacecraft in the blackout area. We have now developed the ability to stably track the spacecraft in the blackout area," said Wu Gang, a technical expert in the measurement and control area.
