July 24 at 14:22, carrying the Sky Experiment Module Long March 5 B remote three launch vehicle, in China’s Wenchang Space Launch Complex punctual ignition launch, about 495 seconds later, the Sky Experiment Module and the rocket successfully separated and entered the scheduled orbit. 25 at 3:13, the Sky Experiment Module and the Sky and the core module assembly in orbit to complete rendezvous and docking. This is the space station that has astronauts in orbit during the first space rendezvous and docking.
At 10:03 on the 25th, the Shenzhou XIV astronaut crew group successfully opened the door to ask the sky experiment module, smoothly into the sky experiment module. This is the first time Chinese astronauts in orbit into the scientific experiment module.
Ask the sky experiment module is the second module of the Chinese space station, is also the first scientific experiment module. What are the moving details before and after the launch? What are the technical breakthroughs in the “new home” of China’s space home?
Millimeter “calculations”, to create a larger and stronger space “new home”
“Ask the sky experiment module is the space station family of large, the total length of the module 17.9 meters, the launch weight of 23 tons, is China’s heaviest, the size of the largest single vehicle, powerful, complex structure, advanced indicators.” Zhang Hao, the overall director-designer of the space station system of the Aisino Science and Technology Group’s Fifth Institute, was introduced.
“Bigger, stronger, more comprehensive, better, more detailed” – in order to make the Asking Sky Experiment Module achieve such goals, the design and development team united to overcome a series of process bottlenecks, developed a number of key technologies, and finally was able to ensure that the Asking Sky Experiment Module high-quality delivery, successful Launch.
A mockup of the Qtian Experiment Module (Photo provided by the Fifth Academy of Space Science and Technology Group)
The working module in the Qtian Experiment Module is the largest manned sealed spacecraft module in China at present, with a module segment length of nearly 10 meters. In order to ensure the normal operation of the load installed outside the cabin, the interface precision of the 72 equipment brackets outside the cabin is very high. But it is because of the “big size”, the precision interface size on the module structure is also magnified by the influence of temperature, resulting in large measurement errors in the process of bracket installation.
At the same time, the current large capsule development using the plant space, product development cycle is long, to achieve a long time constant temperature environment in the plant is very difficult. To this end, Zhao Changxi, chief engineer of manned spaceflight field in 529 Factory of Space Science and Technology Group, led a team to ingeniously propose a virtual constant temperature measurement method, relying on the principle of mathematical matrix calculation, so that the measurement links susceptible to temperature are reliable and stable, and finally realize the high precision of the bracket assembly, successfully carve out a precise shape for the large body of the Asking Sky Experiment Module, and ensure the high reliability of the load outside the Asking Sky Experiment Module work.
The airlock module is one of the most important components of the experiment module, and is the main exit route for future astronauts. However, to weld the exit hatch on the column section of the module, it posed a problem for the developers. Most of the previous models at the hatch for the regular plane curve welding, welding thickness of only 2 mm, while the location of this hatch welding in a saddle-shaped space surface, welding thickness also increased to 5 mm, the traditional manual welding has been unable to meet the requirements. After repeated research tests and a large number of process tests, the Space Science and Technology Group Five Institute developers proposed a new automated welding technology for space curves, independently developed a flexible changeable welding tooling, the successful completion of the sealing hatch door frame welding, all indicators meet the design requirements.
It is the nearly demanding pursuit of perfection, to create a better quality space home.
Precise and accurate, escorting the space station “all-clear”
The Chinese space station consists of a core module and two experimental modules, the launch of these three modules are carried out by the long five B rocket. 29 April 2021, the long five B rocket successfully launched the core module of Tianhe, the opening battle of the construction of the space station. A year later, the Long5B development team was once again in charge of the “arrow” for the launch of the Sky Experiment Module.
Lou Luliang, the deputy chief designer of the aerospace science and technology group a Dean V B rocket, said, the long five B launch of the Sky module, is China’s first large low-temperature rocket to perform rendezvous and docking tasks, “zero window” launch of the rocket’s carrying capacity, into the orbit accuracy and launch reliability have raised higher requirements. Around the mission characteristics, the development team spent a year to complete more than 30 full-arrow flight reliability improvement work.
Lou Luliang said rendezvous and docking is like “threading the needle” in space, in order to more accurately and reliably complete the task, the Long Five B team in optimizing the pre-launch process, expand the launch window and enhance the launch capacity to seek breakthroughs.
The team first adjusted the interlocking workflow of each system from “series” to “parallel”, allowing 2 minutes and 30 seconds for troubleshooting before rocket ignition. Then, “the launch window was widened to 2 minutes and 30 seconds by using “takeoff time correction technology” to meet the requirements of orbit entry accuracy, so that even if the rocket did not launch exactly according to the scheduled window, orbit entry and rendezvous and docking could be completed accurately within this time through later orbit correction.
The team also increased the launch capacity of the Long 5B rocket to no less than 23 tons. However, the difficulty of precise orbiting with a large thrust rocket also becomes greater, which is like stopping a car at high speed with a single kick of the brakes. The “high thrust direct orbit accuracy control technology” and the 20.5-meter-large fairing unique to the L-5B rocket allow the space station module to safely reach its intended orbit.
“Just like an eye can not get into the sand, a small excess may have disastrous consequences for rocket launch and docking.” Liu Bing, deputy director general designer of the Aero-Technology Group I Dean VB rocket, said that in order to ensure the successful rendezvous and docking of the interrogation module, the Long VB team strictly controlled the rocket redundancy through technical communication and analysis and demonstration to minimize the impact on the module docking.
In addition, this year, the L5B team also carried out the future planning and demonstration work of this type of rocket. The team systematically sorted through the data from the previous seven flights and shortened the original 60-day launch preparation time to about 53 days to prepare for subsequent high-density launch missions.
Witnessing the successful launch of the experimental module, the L-5B team was relieved of its heavy burden for the time being. But as they said, “We can only be happy for two hours after each successful launch.” Mengtian Experiment Module launch is coming, they once again carry the heavy responsibility.
From “heavenly questions” to “ask the sky”, the relentless pursuit of space remains unchanged
On July 23, 2020, the Long March 5 remote 4 rocket lifted the Tianqian 1 Mars probe, taking an important step in exploring the vastness of the universe and opening up the era of planetary exploration for the Chinese.
From “Heavenly Question” to “Ask the Sky”, the two launches are exactly two years and one day apart. From the exploration of the planets to the construction of China’s own space station, two years, the astronauts never stop moving forward, planetary exploration project, lunar exploration project, manned space engineering to dream of space one after another, out of a “sky” road.
From “the sky” to “ask the sky”, the word “ask” reveals their common connotation – to explore and ask questions. The “ask” word reveals their common connotation – exploration and questioning. Ask the Sky Experiment Module is not only the astronauts’ “new home” in space, but also carries the important mission of space science research.
As part of the “National Space Laboratory”, the QSTEM will mainly conduct life science and biotechnology research. At present, ask the sky experiment module in space life sciences and biotechnology, microgravity fluid physics, space materials science, space applications of new technology experiments and other four areas of direction planning the deployment of more than 10 research themes, has established more than 40 scientific projects.
Zhang Lu, researcher of the Space Application Center of the Chinese Academy of Sciences, deputy director of the Center for Integrated Technology, introduced China’s second step in manned spaceflight “three steps” period, in Tiangong 1, Tiangong 2 carried out a variety of types of scientific experiments, is based on a single experimental project, experimental samples do not have the ability to replace and demand. Now, entering the space station phase, scientific experiments will be shifted from a single scattered to large-scale group type, in space to build a real scientific laboratory. The scientific experiment cabinet configured in the capsule is the common basic platform for conducting a variety of scientific experiments.
Ask the four scientific experiment cabinets in the sky experiment module. (Photo provided by China Manned Space Engineering Office and Chinese Academy of Sciences)
“In addition to individual experimental cabinets, most of the experimental cabinets have all unified external interfaces, and the interfaces of the internal loads are made into national standards, which are very convenient for maintenance and replacement. At the same time, the experimental cabinets can also be compatible with international standards, ready for subsequent international cooperation.” Zhang Lu said.
In the future, the space station will also carry out 65 research programs in four major fields, including space life science and human research, microgravity physical science, space astronomy and earth science, and new space technology and applications, including nearly 1,000 research projects.
Wang Ke, deputy director of the space application system and director of the Integrated Technology Center of the Space Application Center of the Chinese Academy of Sciences, said, “The completion of the space station is just the beginning of China’s space science research. Subsequently, universities, research institutes and school and university students across the country can participate in space science experiments on the space station. We also welcome researchers from all over the world to use our platform to conduct scientific research together.”
