Chang ‘e IV will land on the moon next year. China experts reveal how to grow potatoes on the moon.

　　The movie "Mars Rescue" describes the plot of the protagonist trying to grow potatoes on Mars. Now, this vision is expected to be completed by China. In 2018, the popular science payload "Lunar Micro-Ecosphere" will land on the lunar surface as a special passenger on Chang ‘e IV, where potato seeds, Arabidopsis seeds and silkworm eggs will be placed. Two kinds of plants will take root and sprout within the 100-day experimental period and produce the first flower on the surface of the moon. Silkworm will also complete the complete life cycle of egg hatching, larval growth and development and cocoon breaking into butterflies.

　　The reporter of Beijing Youth Daily learned that Professor Xie Gengxin, the chief designer of "Lunar Micro-Ecosphere", said that by the end of 2018, the popular science payload will "ride" Chang ‘e IV to the moon, realizing the first biological experiment on the surface of the moon. This biological experiment will be broadcast live to the whole world through a small camera.

　　On June 18th, Xie Gengxin, the chief designer of "Lunar Micro-Ecosphere", was interviewed by Beijing Youth Daily, and introduced in detail the idea and process of this biological experiment, such as planting potatoes on the moon. In Xie Gengxin’s view, although many difficulties need to be overcome, this experiment is of far-reaching significance. It will be the first lunar biological experiment for human beings, which is of great significance to the future survival of human beings on extraterrestrial planets.

　　The first biological experiment on the surface of the moon

　　Beiqing Daily: Why was there such an experimental idea at the beginning?

　　Xie Gengxin: Actually, growing organisms on other planets is an area that many countries are studying. China’s previous exploration has landed on the moon, and this experiment is another innovation in the exploration process.

　　Beiqing Daily: Who is conducting this experiment?

　　Xie Gengxin: This project is a popular science load led by Chongqing University. It has been an experiment for more than two years. In addition to Chongqing University, Hunan University, Beihang University, China Aerospace Science and Technology Group and other universities and enterprises have also participated in it, involving multiple R&D teams with interdisciplinary subjects such as machinery, control, environment, biology, optics and energy. There are more than twenty staff members at the core of the team.

　　Beiqing Daily: What is the "lunar micro-ecosystem"?

　　Xie Gengxin: This is a cylindrical device, with a height of 18 cm and a diameter of 16 cm. It is made of aluminum alloy, and the national flag of China and the signs of Chongqing University and Research Center are affixed on the surface. The weight of the whole popular science load lunar micro-ecosystem is 3 kg, but its cost is more than 10 million yuan, and the camera alone is 600 thousand yuan.

　　Beiqing Daily: Compared with other countries, what is the international position of this exploration?

　　Xie Gengxin: This exploration in our country is the first biological experiment on the moon, which is ahead of the United States, Russian and other countries. This exploration will also prove that among many countries in the world, our country’s space exploration is changing from the previous follow-up to the leading and leading stage.

　　Different from the first flower in outer space opened by NASA space station in the United States last year, our experimental location is 380 thousand kilometers away from the earth, which is much farther than that of the International Space Station, which is more than 300 kilometers away from the ground.

　　Planting with large temperature difference and strong radiation on the moon faces many challenges.

　　Beiqing Daily: What are the difficulties to overcome this time?

　　Xie Gengxin: On the moon, it is 14 consecutive days of daylight and then 14 consecutive days of darkness. The high temperature can reach more than 100 degrees Celsius, and the low temperature drops to more than 100 degrees Celsius below zero.

　　In addition, the ultraviolet rays on the moon have not been filtered, and the survival of animals and plants needs to face harsh environments such as high radiation and microgravity. This is far from the living environment on earth. These are all difficult problems to overcome.

　　Beiqing Daily: What do potatoes, Arabidopsis and silkworms live on?

　　Xie Gengxin: Our "lunar micro-biosphere" is actually simulating the living environment of animals and plants on the earth. The device will contain water and equipped nutrient solution, and the temperature in the jar will be kept between 1℃ and 30℃ through certain technology, and the humidity and nutrients inside will be controlled well.

　　In addition, the photosynthesis of animals and plants is carried out by absorbing the natural light of the moon, and there is no light in the whole device. The light pipe in the "jar" absorbs the natural light on the surface of the moon for photosynthesis, and the released oxygen is absorbed by silkworm eggs, and then the silkworm eggs discharge carbon dioxide and domestic garbage for plant seeds.

　　Beiqing Daily: How can animals and plants carry Chang ‘e to the moon to overcome the overweight problem?

　　Xie Gengxin: A difficult problem in the experiment process is how to fix the seeds and silkworm babies in a "jar" so that they will not be scattered due to overweight and other pressures during launch.

　　We have repeatedly calculated the design and weight of the container, for example, because the soil is too heavy and the utilization efficiency is not high, we chose nutrient solution, and the seeds and silkworm babies have also been fixed under overweight conditions through technology.

　　Potatoes are expected to be a food for human beings to survive in space.

　　Beiqing Daily: Why did you choose potato, Arabidopsis and silkworm?

　　Xie Gengxin: First of all, from the biological conditions, the selected plants and organisms should be relatively resistant to high and low temperatures, and the growth cycle should not be very long. After experiments, these three kinds of animals and plants are relatively qualified.

　　In addition, the choice of potato is also to provide support for the next step of human survival in space. At present, many countries and research institutions in the world regard potato as the main food for human survival in space.

　　Secondly, the choice of animals and plants will also be close to the life of ordinary people and conform to the cultural tradition of China. Potatoes are the most common food, and silkworm babies are cute. There is also a step of breaking cocoons into butterflies in the growth cycle, which has a good moral and symbolizes the progress and innovation of China in space exploration.

　　Beiqing Daily: Is the potato cultivated in the later period expected to become human food?

　　Xie Gengxin: It’s a possibility. We will conduct experiments on the earth at the same time and under the same conditions, and compare and analyze the data of the two. Through experiments, it is possible that the quality and yield of potatoes planted on the moon are relatively high, but this needs further research.

　　Beiqing Daily: Is it possible for humans to survive on the moon in the later period?

　　Xie Gengxin: If plant seeds can germinate, grow and bloom in this environment, silkworm eggs can hatch normally, larvae can grow and develop, and break cocoons into butterflies, which shows to some extent that it is not a dream for human beings to live on the moon.

　　If the experiment is successful, it will provide technical support and lay a foundation for human beings to carry out the survival of extraterrestrial planets. Just as the micro-ecological circle on the moon is infinitely large, theoretically, human beings can also live on the moon.

　　Text/reporter Zhang Xiangmei Intern reporter Zhang Cong