Yesterday (8th) afternoon, the tianzhou-4 cargo spacecraft mission organized a regional joint training between systems before launch. After the joint training, it marks that all systems in the region have the conditions to carry out the launch mission. In addition to the "ignition and launch", this is a comprehensive simulation exercise with the largest and most complete test measurement, control and communication system. It is also the last joint exercise before launch.
This paper mainly focuses on the inspection of various works in the launch and orbit stage of the combination of Tianzhou 4 cargo spacecraft and Long March 7 remote 5 carrier rocket. Beijing flight control center, Wenchang space launch site, Xi'an Satellite TT & C center and all TT & C stations of the mission implement joint commissioning and joint control, and make all preparations before launch. During the joint training, the participating systems were closely organized, the commands of commanders at all levels were accurate, the technicians were skilled in operation, and the systems cooperated closely with each other to ensure that all procedures were carried out in an orderly manner. At present, it is predicted that the weather conditions on the day of launch meet the launch requirements. After the joint training, it marks that all systems in the region have the conditions to perform the launch mission, and the subsequent filling and pre launch preparations will be completed.
The new generation command and display system provides information support for launch
On May 7, Tianzhou 4 cargo spacecraft was smoothly transferred to the launch area at Wenchang space launch site.
In the region wide joint training ended yesterday, the newly launched cross platform command and display system provided more accurate information support for commanders to judge the flight status of rockets.
The space launch command and display system can realize the real-time display of rocket test and launch process, tracking of measurement and control equipment, working conditions of major support systems, communication link conditions and meteorological facts. It is the center of rocket launch command and decision-making.
Li Wenchao, engineer of the command and control center of Wenchang space launch site: during the flight of the rocket, the ground tracking equipment and the rocket itself will transmit massive real-time data to the center. Our job is to interpret, process and use these data, convert them into visual information, show the rocket flight situation concisely and accurately, and provide information support for the commander to quickly and accurately judge the flight state of the rocket.
In recent years, the launch missions of Wenchang space launch site have shown the characteristics of various types of launch vehicles and loads, multiple parallel missions with different cycles, scattered distribution of equipment and personnel, etc. In view of the new situation and new characteristics, the command and control center transferred elite soldiers and strong generals, established a scientific research team, actively promoted the research and development of a new generation of command and display system, and realized the functions of mobile cross platform rocket flight situation display and auxiliary decision-making.
Li Qingliang, director of the technical office of the command and control center of Wenchang space launch site: we boldly carried out a number of technological innovations, such as integrating telemetry images (images collected by the camera on the rocket) into the system. In addition, the tracking of measurement equipment is automatically evaluated through the expert system, and the network cloud method is adopted to enhance the stability of the system. These technological innovations give commanders a better use experience and simpler information display, but they contain richer content and can provide more decision-making basis.
The Long March 7 yao5 rocket will lift the Tianzhou 4 cargo spacecraft
The tianzhou-4 cargo spacecraft is the first spacecraft in the construction stage of China's space station. It will provide six-month in orbit stay, space station assembly and construction, and material support for a variety of space application fields for the three astronauts of shenzhou-14 crew.
The Long March 7 rocket, which is responsible for lifting the Tianzhou 4 cargo spacecraft, has previously completed three launch missions from Tianzhou 1 to Tianzhou 3. Compared with the Tianzhou III mission, the rocket test and launch process of the Tianzhou IV mission is shortened from 35 days to 27 days. By optimizing the design and process, the adaptability of the rocket to carry out the launch mission is effectively improved.
Shen Dan, deputy chief designer of the model office of the Long March 7 carrier rocket of the first Academy of Astronautics: the optimization of the main measurement and launch process is reflected in several aspects. First, some inertial devices on the arrow are directly installed on the arrow after the on-site test of the general measurement, and then shipped to Wenchang launch site with the arrow. The advantage is that the installation and testing time to the launch site is no longer occupied. Another is that in the filling process, in the past, liquid oxygen was filled after kerosene filling. These two processes are completely connected in series. So this time, in the cooling stage before liquid oxygen filling, kerosene is still filling, which makes the whole original serial process compressed. The shorter the storage time of kerosene in the arrow body, the smaller its temperature rise and the better the quality of propellant.
During the launch mission, in order to realize the rendezvous and docking between the cargo spacecraft and the Tianhe core module, it is necessary to accurately push the cargo spacecraft to the space orbital surface where the Tianhe core module is located, which requires the rocket to ignite and lift off at the predetermined time in milliseconds. In order to better adapt to the fault situation and improve the ability of the rocket to launch on time, the Long March 7 remote 5 launch vehicle uses the iterative guidance algorithm to expand the launch window.
Shen Dan, deputy chief designer of the Long March 7 launch vehicle model office of the first Academy of Astronautics: even if it deviates from the standard take-off time by less than two minutes, it will find a suitable route in the air to make us meet the space station according to the timing and space position required by the overall requirements of the project.
In addition, it is worth mentioning that for the first time, the Long March 7 remote 5 carrier rocket takes the Beidou satellite navigation system as the first priority of navigation reception.
Shen Dan, deputy chief designer of the Long March 7 carrier rocket model office of the first Academy of Astronautics: that is to say, after the rocket takes off, the navigation is given priority to Beidou. We have also fully tested this change. The assessment is still very reliable. In addition, it can switch the navigation system in real time, which can not meet the requirements of other navigation systems.
In terms of rocket engine system, yf-100 and yf-115 have also completed a number of process and technical improvements, which not only improves the reliability of power system, but also makes the rocket safer.
Communication team: the only link connecting the ground during rocket flight
With the launch imminent, there is also a busy front-line team, the communication team in the space launch project. As the only link between the rocket flight and the ground, communication plays a vital role.
In the communication room, Zeng Huiqing, the person in charge of the power supply post, sat in front of the display and was absorbed. Her post is equivalent to the "heart" of the communication system, and her main responsibility is to ensure the uninterrupted power supply of the equipment in the communication information center.
Zeng Huiqing, head of the power supply post of Wenchang communication station: we have standardized every step from the command to the personnel operation. Space launch missions, voice command, satellite images, frequency signals, meteorological information... The transmission of these information depends on our communication lines.
Hu baokai is the line maintainer of Wenchang communication station. It usually takes more than four hours to walk around the line. Dressed in "island black", Hu baokai, who is in his twenties, looks much older than his actual age.
Hu baokai, line maintainer of Wenchang communication station: no matter how hot it is in summer, we are all on the line. Although we are not at the launch site, I am also very proud when the rocket took off.
The communication team carefully summarized the information changes of various types of rockets, revised and improved the plan and optimized the disposal process. According to the characteristics of rocket communication support, they carried out special technical state change identification and risk analysis, carried out machine line renovation and virus detection and killing of the whole network, conducted in-depth equipment inspection, and completed hundreds of communication line circuit tests.
Wang Gang, network maintenance technician of Wenchang communication station: to check whether the network management gives an alarm during the rocket launch, closely monitor the equipment and link status, observe whether the network traffic is normal, and always pay attention to whether there are viruses or network attacks. Foolproof and complete success is our only option.