Recently, the Tianzhou-7 cargo spacecraft flew into space to deliver new cargo to the Shenzhou-17 astronauts who were busy at the China Space Station.

　　Higher efficiency, heavier cargo... After the space station entered the application and development stage, there have been many new changes in delivering goods to space.

　　Increased loading capacity

　　The Tianzhou-7 cargo spacecraft is the cargo spacecraft with the largest cargo transportation capacity, the highest cargo efficiency, and the most complete on-orbit support capabilities in the world.

As the first launch mission of China's manned space program this year, Tianzhou 7 will transport supplies to the two crews of Shenzhou 17 and the subsequent Shenzhou 18 in orbit.

　　Previously, the launch of Tianzhou spacecraft was often based on the principle of "before the troops arrive, food and grass go first", that is, before each flight crew sets off, a cargo spacecraft is launched first to prepare supplies for the astronaut crews who are about to depart.

Tianzhou-7, on the other hand, transports supplies for two crews, and the launch frequency of the spacecraft is adjusted to three launches every two years.

　　The reduction in launch frequency is due to the increase in the loading capacity of the Tianzhou cargo spacecraft.

Starting from Tianzhou-6, the Tianzhou series spacecraft have been "upgraded" to improved cargo spacecraft, with increased loading space and loading weight.

Tianzhou 7 carries more than 260 pieces of astronaut systems, space station systems, application mission areas, cargo spacecraft systems and overall engineering cargo. The total weight of the transported materials is about 5.6 tons. It has the characteristics of carrying many types of cargo and many large cargoes.

Among them, Tianzhou-7 carries large cargo such as customized test payload packages, each weighing more than 100 kilograms, which will be used in space station orbit operations, space on-orbit scientific experiments, and astronaut life support.

　　Living supplies for the astronaut crew are essential.

This time Tianzhou-7 prepared 2,400 kilograms of living supplies for the astronaut crew, including Spring Festival goods for the Year of the Dragon, fresh fruit and vegetable gift packages, including nearly 90 kilograms of fresh fruits.

The crew of Shenzhou 17 will spend the New Year of the Year of the Dragon in space, and Tianzhou 7 has brought them a "blind box" for the Year of the Dragon.

　　According to reports, China's space station has sufficient supplies, which can not only support normal astronaut residency, platform maintenance and upgrades, and large-scale on-orbit experimental missions, but can also support astronaut residency for an additional three months in an emergency.

　　Accurate replenishment

　　At present, China's manned space program has established a material information system that links space and ground, developed a material design life and design usage model, achieved accurate replenishment, and improved efficiency.

According to experts, as the on-orbit data of missions in the construction phase accumulates, the model will become more and more accurate, and subsequent needs can be accurately estimated, so as to "make up for what is missing", even if there are too many belts, there will be no more belts, and the supply efficiency will continue to improve. promote.

　　In addition, this time the Tianzhou-7 cargo spacecraft adopted a 3-hour rapid rendezvous and docking scheme for the first time. Compared with the conventional 6.5-hour rapid rendezvous and docking scheme, it further compressed the docking time, provided a more efficient way for the space station to transport materials, and alleviated various tasks. The stress on the system during task execution.

At the same time, the use of this solution improves the autonomous rendezvous and docking capabilities of cargo spacecraft and further promotes the development of rendezvous and docking technology.

　　In this delivery mission, Tianzhou-7 also brought a "new member" - a new power socket that can independently replace fuses in orbit.

The power socket is only 10 centimeters long and wide. Although it is petite, it has many on-orbit maintenance functions such as quick disassembly and assembly, slot alignment, and non-detachment locking. It will greatly improve the on-orbit power consumption of astronauts on the space station. Play a decisive role.

　　In the early stages of the construction of the space station, once a fuse blows in the power socket, the whole machine can only be replaced. The astronauts will bring the power socket back to the ground and return it to the factory for repair. The maintenance cost is high and the cycle is long.

With the gradual increase of space scientific experiments in the space station, there are more and more types of loads connected to the power supply socket, and the power consumption status and working conditions are more complex. The probability of abnormal blowing of the fuse inside the power supply socket increases, and the method of returning the whole machine to the factory for repair has changed. Adapt to the new needs of manned spaceflight.

　　To this end, the R&D team of the Fifth Academy of Aerospace Science and Technology Group has carried out research on fuse assembly maintenance technology based on microgravity environment. The power supply socket maintenance method has been optimized from "whole machine maintenance" to "external device" maintenance method.

After adopting the new generation of power supply socket, astronauts only need to remove the external fuse component of the power supply socket and replace it with a new component during on-orbit maintenance, which can significantly save costs and shorten maintenance. cycle.

　　Increased scientific load

　　After entering normal operation, space science experiments play an increasingly important role in astronauts' work.

Currently, there are 25 experiments and test cabinets in the Chinese Space Station, and new experimental modules, equipment, etc. are also constantly being rotated.

　　It is understood that the space application system has a total of 61 uplink products in the Tianzhou-7 mission, including 16 standard cargo packages, 1 set of cell uplink life support support device, 1 set of 4°C uplink microfluidic chips, etc.

After these application materials are uploaded, they will be transferred to the space station experimental facilities to carry out a total of 33 scientific experiments (experiments) such as space life science, space material science, microgravity fluid physics and combustion science. The research units involve 10 research institutes and 8 institutes. University.

After these application materials are delivered to the space station, they will be installed in corresponding experimental devices by on-orbit astronauts to carry out experiments. Some experimental results can be transmitted back to the ground in real time, and some experimental samples will be brought back to the ground by astronauts for further research.

In addition, Tianzhou-7 also carries multiple scientific payloads, which are of great significance to subsequent space scientific research.

　　In this Tianzhou-7 mission, a scientific experiment jointly designed by researchers from Tsinghua University, the Institute of Microbiology of the Chinese Academy of Sciences, the Shanghai Institute of Technical Physics of the Chinese Academy of Sciences, and Dalian Maritime University used anaerobic bacteria called methanogens to Archaea were sent to the Chinese Space Station to verify whether they could survive in an environment simulating Mars and in the extreme environment of cosmic radiation, and to help humans explore the major mystery of whether extraterrestrial life exists.

　　Liu Yao