On June 4, the Shenzhou 15 manned spacecraft Reentry capsule bathed in the morning sun, escorted the Shenzhou 15 flight crew back to Earth after six months of "space travel", and successfully landed in the predetermined area of Dongfeng landing site.
"Eagle report, find the 243 signal!" This is a password during the return of the manned spacecraft. Compared with the well-known password such as "feel good", it does not attract public attention, but it is crucial for the Human spaceflight search and rescue recovery technical team.
"When the Reentry capsule breaks through the 'black barrier' and opens the parachute, it will send out 243 signals, which means that the spacecraft is returning according to the normal procedure." Song Lei, head of the Team leader of China Electronics Technology Human spaceflight Search, Rescue and Recovery Technology, said that in this process, the series of directional finders independently developed by China are like "tailwind ears", capturing the first signal sent by the Reentry capsule after breaking out of the 'black barrier' at the first time, Lock the exact position of the Reentry capsule and send a report - "243 signal tracking is normal".
This is the first manned landing recovery mission of the China Manned Space Program entering the application and development stage of the space station. Based on the key node information of "normal signal tracking" provided by the orienteering instrument, Dongfeng Landing Site once again achieved "manned landing".
"The landing and recovery of the Reentry capsule is the 'finale' of the manned flight mission, and is also a key link to the success of the mission. Finding the Reentry capsule and rescuing astronauts in the shortest time is the top priority of the landing and recovery mission." Song Lei told reporters that the team independently developed a series of orienteering products, which are equipped on platforms such as transport planes, helicopters, search vehicles, and rescue ships, and can instantly receive the "call" signal sent by the Reentry capsule.
According to him, the astronaut radio station developed by the team is a "bottom line" means of voice communication between astronauts and ground search and rescue forces during low altitude flight of the Reentry capsule and after landing. After the main parachute is opened, the astronaut's radio station takes over the "relay baton" of the measurement and control communication system, ensuring that the astronaut's voice is clearly transmitted to the Beijing Flight Control Center lobby.
From the Reentry capsule to the re-entry orbit at variable speed, to the Service module separating from the Reentry capsule, from the Reentry capsule to the atmosphere, to the safe landing... Shenzhou 15 returned from the orbit of the space station about 400 kilometers from the ground, and landed accurately at the Dongfeng landing site, which is as difficult as "10 rings in a million miles".
At each step of return, the TT&C communication system needs relay traction to complete telemetry and external measurement to receive and send commands, observe and analyze the position, speed and flight attitude of the Reentry capsule. At Dongfeng Landing Site, CETC research team deployed portable stations, airborne stations, on-board stations, fixed stations and other station type and multi model satellite communication systems, woven a dense and safe measurement and control communication network, like "Stethoscope", "remote controller" and "mobile phone", to measure the flight trajectory in real time, monitor the power supply, temperature, pressure and other parameters of the Reentry capsule and various physiological parameters of the astronauts, transmit the instructions sent from the ground in real time, command the Reentry capsule to change orbit Adjust posture, transmit voice and image data in real-time, allowing real-time communication between the ground and astronauts.
With the "Mountain and Sea Tracking End" dispatching command sounded, there were warm applause and cheers in the Bitwise operation shelter of the measurement and control point, which meant that the Shenzhou 15 Reentry capsule was successfully dressed