The moon moves along the elliptical orbit and moves to near the perigee, making people feel extraordinarily large and bright, known as the "super moon." Recently, it has coincided with the “Super Moon”, and its attention has increased significantly around the world. For many Chinese people, in addition to admiring the praises of the "super moon", there are also concerns from the bottom of my heart. Because it is just above the bright moon, our No. 4 is there, experiencing the harsh test of moonlight and ultra-low temperature.

The lunar environment is terrible. The maximum temperature during the day is nearly 130 degrees Celsius, and the lowest is below 180 degrees Celsius. It is undoubtedly the forbidden zone of life. However, since the soft landing of the moon, the No. 4 has not only survived stubbornly, but also successfully carried out a series of scientific exploration activities, including the experiment of lunar biosciences, which grew first among the peerless world. The green leaves create a history of human lunar exploration.

The No. 4 bioscience experiment can be traced back to 2016. The National Defense Science and Technology Bureau, the Ministry of Education, and the Chinese Academy of Sciences jointly launched a lunar exploration load creative design collection activity. The “Moon Micro Ecosystem” design proposal proposed by the Joint Research Center of Deep Space Exploration of the Ministry of Education of Chongqing University stood out from the numerous proposals for the collection activities and became the selection scheme for the No. 4 carrying project. During the preparation of the bioscience experimental load project, the load team encountered various problems. They rely on the aerospace spirit to solve problems one by one in experimental species screening, tank engineering design, and ground verification testing.

The No. 4 bioscience experiment load was loaded with cotton seeds, rapeseed seeds, yeast and fruit fly eggs. Although there are not many types, it is not easy to select these types from many biological species. The research team spent two years on this, succumbing to various factors, and the species selected during the period was changed several times.

At the beginning, the project was not very restrictive. The team's ideas were very open. Even considering the carrying of turtles, it meant that it competed with Yutu No. 2 to highlight the Chinese culture. However, due to size, activity space, and oxygen constraints, the turtle was also abandoned. The experimental science team finalized the selection of species around the three major goals. First, it has the significance of biological experiments, the second is to achieve the purpose of popular science knowledge, and the third is to show the world the major engineering and technical capabilities and levels of China. The final selection was "cotton seeds, canola seeds, Arabidopsis seeds, potatoes, yeast and fruit fly eggs".

The No. 4 biological science experiment load brings together the wisdom of researchers in many departments. The biological science experiment is not only a research but also an engineering project. To be engineered, several core teams must be condensed. Big projects have to be done more carefully. The experimental science team worked hard on the details. There were two options for the daylighting scheme of the load creatures. One was to use incandescent lighting, and the technology was mature. The second was to use natural light, but there was no ready-made solution. Considering that this load is not just about doing a space biology study. The most important thing is to spread the biological knowledge to the public, such as photosynthesis in the moon. Therefore, in the load, it takes a lot of time and energy to use a special device to achieve the purpose of using the natural light of the lunar surface sun, although the difficulty is greatly increased, but the significance is greater.

On the back of the moon on the 4th, the back of the moon is the first time for humans. There is no detailed historical data for reference, and no experience can be used for reference. The same is true for the experimental load. The team can only analyze and predict the environment of the moon back, and it is inevitable that there will be errors. In order to adapt to the temperature of the lunar surface after soft landing as much as possible, the experimental team selected 6 kinds of organisms that are resistant to low temperature and high temperature. This move proved to be very far-sighted. The data returned shows that during a soft landing, the temperature inside the load reached more than 30 degrees Celsius, while the previously predicted temperature was 20 degrees Celsius. The warm and heat-resistant cotton seeds successfully completed the process of germination and growth under high temperature, and the crown of the "first lunar bud of the moon" was taken.

Constrained by a weight of 3 kilograms, the load also needs to include essentials such as tanks, water, soil, etc., and the resources that can be carried are very limited. Image capture of experimental loads can only be achieved with photos returned by two point-and-shoot cameras. The special environment puts extremely demanding requirements on the camera in terms of radiation resistance, high and low temperature resistance, vibration resistance, vacuum, etc., making its function as simple as possible, such as no focusing, and can not move. When analyzing the photos taken by two point-and-shoot cameras, the experts highly suspected that other seeds also sprouted, and the fruit fly eggs may also develop and hatch. However, only the cotton germination in the picture is very clear, so after careful consideration, only the cotton seed germination was confirmed. Although a little regrettable, the load team is still very productive. ”

The experimental load team released several experimental pictures to the public, and nearly 400 pieces were being used for scientific research, revealing the characteristics of seeds growing and sprouting under the special environment of microgravity, high radiation, high vacuum and high temperature difference. These data are open, and foreign peers are welcome to cooperate in research to create conditions for human beings to better understand and use the lunar environment. At present, Europe, the United States, and China have plans to build a lunar base, which necessarily involves biological activities. This experiment is an important accumulation of data and experience technology, laying the foundation for the future construction of the lunar base.