From “God Five” to “God Fourteen”: Flying to the common space dream of mankind
2022-06-05 09:33:58Source: CCTV International Online
International Online Report (Reporter Wu Shiyun): At the press conference on the Shenzhou 14 manned mission held on the morning of the 4th, Lin Xiqiang, spokesman for China’s manned space engineering and deputy director of the China Manned Space Engineering Office, announced that the general manager The headquarters studied and decided to launch the Shenzhou 14 manned spacecraft on the morning of the 5th, Beijing time. From “God 5” to “God 14”, what progress has China’s aerospace technology made? How far is humanity from immigrating to the universe? How do Chinese astronauts carry out international cooperation? Why must international cooperation in the aerospace field be carried out? Faced with these questions, Zhou Binghong, a researcher at the National Space Science Center of the Chinese Academy of Sciences, gave his answers.
Reporter: From “God 5” to “God 14”, what progress has China’s aerospace technology made?
Zhou Binghong: In October 2003, China’s first manned spaceship “Shenzhou V” was successfully launched. Since then, China has become one of only three countries in the world that has mastered manned spaceflight technology. In the past 19 years, China has launched manned spacecraft eight times, and the “Shen 14” is the ninth launch, basically reaching the technical level achieved by the United States and Russia through hundreds of launch experiments.
“Shen 5” to “Shen 14” spanned four technical steps. The first step is for the astronauts to get out of the capsule. The astronaut Yang Liwei of Shenzhou 5 will not leave the cabin, and the astronauts after him can leave the cabin; the second step is the rendezvous and docking of the spacecraft in space. In the early days, there was an orbital module on the Shenzhou spacecraft of our country, which could be used as an airlock after being left in orbit. It was equipped with a docking port to realize the rendezvous and docking of the spacecraft and the space station, which expanded the life range of astronauts; the third step It is the spacewalk after the astronauts leave the capsule. At this stage, the performance of my country’s spacesuits and the ability to control movement during walking are tested; the fourth step to break through is the uninterrupted long-term presence of people in the space station. This requires us to roll the spacecraft to the space station. In fact, when God 13 was launched, God 14 was on standby in the final assembly plant of the launch site. If there was any unexpected situation, it would be launched immediately, and the astronauts above would be taken over. This is a major technological juncture – making space flight life-saving.
Reporter: How far are we from colonizing space?
Zhou Binghong: Every advancement in space technology means that people can live in space for a longer time. To date, the longest continuous human existence in space is 437 days, which was created by Russian cosmonauts on the Mir space station. China’s space survival time has grown from Yang Liwei alone in space for one day to three astronauts who can survive for 180 days in the space station. If you want to immigrate to space, you must at least increase the survival time to more than 100 years.
Why does the International Space Station only survive for half a year to a year? This is because astronauts need a lot of life supplies to survive in space. The life support and resupply technology of Chinese astronauts has gone through three stages, and now the fourth stage is being attempted.
In the first stage, Yang Liwei had no supplies when he went to the sky, he had already had enough food before the launch, and he would come back after a day;
In the second stage, all supplies are brought up from the ground at one time. This price is very high, because a person eats dozens of kilograms to hundreds of kilograms of things a month, and at the same time uses physical and chemical methods for material circulation. For example, oxygen is separated from the air by physical means and recycled, and water is recycled by chemical means;
The third stage is the “semi-closed ecosystem”. The current space station can not only cycle physically and chemically, but also grow vegetables. Growing vegetables on a space station is difficult because water flow has no direction in microgravity, making it difficult for plants to absorb water and nutrients. In addition, the energy supply of the space station is not as abundant as that on Earth. The so-called “semi-closed” means that an additional part of the fertilizer water needs to be brought up;
The fourth stage is “totally closed ecosystem”. For example, human excrement can become fertilizer for plants, animals or plants can be decomposed by microorganisms after death, the entire ecosystem can be produced and sold by itself, and people can survive on a completely enclosed space station for decades.
To establish a completely closed ecosystem requires the use of local resources as much as possible. Specifically, the moon and Mars are the most ideal immigration destinations right now. Zhou Binghong explained: “The moon and Mars both have a lot of water. A few months ago, the United States has realized the production of oxygen from carbon dioxide on Mars. And Mars is also rich in methane. Methane itself is a good rocket propellant. In the future, it can be Build unmanned factories on Mars.”
In order to simulate the harsh environment of space, the United States established Biosphere II in the desert region of the earth to conduct experiments in a fully enclosed ecosystem. It was not only the technical difficulties that caused the trial to fail, but also the psychological difficulties of the participants. At the beginning, seven or eight scientists were very confident and courageous, but after a period of time (it was reported that it was 2 years, but it was not completely closed), they were not willing to continue to cooperate, because they stayed inside psychologically. So uncomfortable. But just last year, China broke the record for the longest time in the world for a simulated airtight test of a capsule’s survival. Eight volunteers from Beihang University lived on the “Yuegong No. 1” for 370 days, and the degree of system closure reached 98%.
Reporter: How do Chinese astronauts carry out international cooperation? Can you talk about your own experience?
Zhou Binghong: I studied in France and developed higher-quality materials in space in the Microelectronics and Materials Laboratory. I remember that at that time, China launched a space microgravity experimental satellite “Practice No. 10”. Before the launch, a weightlessness test was required. Domestic microgravity drop towers can only provide a weightless environment for three seconds, while European weightless aircraft can provide a weightless environment for tens of seconds, which is rare. Many of my colleagues, juniors, and students have conducted experiments on their weightless planes.
Back then, we did experiments on foreign weightless planes. Now, since Europe does not have its own space station, many European astronauts have started to learn Chinese and look forward to coming to China for training and cooperation.
Reporter: Why must international cooperation in the space field be carried out?
Zhou Binghong: From the point of view of scientific research, I think there are two reasons: the first reason is that aerospace technology has inspired our human spirit of exploration, that is, it goes out. The second is the spirit of cooperation to jointly protect the earth. Both are part of a community with a shared future for mankind.
We are currently doing asteroid defense research, which is to protect our Earth from asteroid impacts. There is now a theory in the scientific community that the dinosaurs died out 65 million years ago when an asteroid with a diameter of about ten kilometers hit the earth. Humans may also face such asteroid impacts in the future.
About ten years ago, scientists discovered an asteroid called Apophis with a diameter of 370 meters. It was initially calculated that it had a few percent probability of hitting the earth in 2029. At that time, scientists from all over the world were actively looking for solutions. American scientists calculated that it would take 76 Boeing Delta Heavy rocket launch vehicles to hit him. Our research group has proposed the “rocking with stone” plan to capture the stones near Apophis and the “last-stage hitting” plan using the last stage of the rocket. No matter what kind of plan, the required preparation time, economic cost, and labor consumption cannot be completed by a country alone. After observing Apophis for a long time, we now predict that there is a high probability that it will not hit Earth.
At present, more than 2,000 asteroids threatening the earth have been discovered. However, the asteroids we have discovered now are only a small part of the real existence, and such observation and exploration work also requires the joint efforts of scientists all over the world.
Can we avoid a dinosaur-like demise? The current capacity is not enough. For this reason, no matter which country we come from, we should abandon our fears and prejudices, and uphold the spirit of science, bravely go to space to find answers.