Sun Mingyuan, intern reporter of science and Technology Daily
At the Chinese and foreign press conference held by the Propaganda Department of the CPC Central Committee at the end of 2021, Dong Caili, director of the overall Technology Bureau of the China Manned Changzheng Engineering Co.Ltd(603698) office, revealed that China is currently carrying out key technology research and program deepening demonstration for manned lunar landing. For a time, the topic of manned lunar landing returned to the public view.
In January 2019, Wu Yanhua, then deputy director of the National Space Administration and deputy commander in chief of the lunar exploration project, said at the press conference of the state information office that China is organizing scientists to pay close attention to research on manned lunar landing and has not yet reached the decision-making stage. In the following three years, China's aerospace industry has made many important achievements. Tianwen-1 landed on Mars, the unmanned lunar exploration "Chang'e project" completed the three major goals of "orbiting, falling and returning", and the Chinese space station entered the era of long-term manned presence... China's manned spaceflight has brought more and more surprises and expectations to the public. However, the "schedule" of the manned lunar landing mission has not been determined.
After the completion of unmanned lunar exploration, manned lunar landing is the second step in the "three big steps" of China's lunar exploration project, and it is also the premise of realizing long-term residence in the moon. How far are we from manned lunar landing from putting it on the agenda to realizing it? Can China's space station help manned lunar landing?
Although manned lunar landing costs high, it has great long-term returns
On December 10, 1972, Apollo 17 successfully landed in the South The Pacific Securities Co.Ltd(601099) , marking the completion of the sixth U.S. lunar landing mission. So far, the "Apollo program" has come to an end, and "Apollo 17" is the last manned lunar landing in human history. In nearly half a century after this mission, the human manned lunar landing plan fell into a "Silence". Neither the government nor enterprises have engraved the famous "one small step" of American astronaut Armstrong.
"There is no doubt that manned lunar landing is extremely costly and risky." In an interview with science and technology daily, Yang Yuguang, vice chairman of the Space Transportation Committee of IAF and researcher of the second Academy of Aerospace Science and industry of China, explained the reason for the "Silence" of human manned lunar landing. In the "Apollo program" in the 1960s, the United States invested up to $25.5 billion, which was a huge sum of money, accounting for about 4.5% of the total budget of the U.S. government at that time. Each "Saturn V" heavy rocket used for landing on the moon is worth as much as an aircraft carrier. Under the special historical conditions of the cold war space race, such a huge investment was made.
With the changes in the world situation in the 1970s, the United States terminated the expensive manned lunar mission, and other countries were temporarily unable to carry out it. This is the reason why the manned lunar landing fell into "Silence". Today's lunar exploration activities focus on the combination of scientific exploration and economic interests, focusing on the exploration of lunar resources, so as to lay a foundation for the development and utilization of lunar resources in the future.
In addition to the huge cost, the manned mission to the moon still has a very high risk. "The fault tolerance rate of the lunar orbit intersection and docking scheme is very low, and any small error in any link may lead to mission failure. This is also the reason why Dong said that further technical research and scheme demonstration should be carried out." Yang Yuguang said.
However, he does not think that manned lunar landing is just a "face project". Take Apollo 17 as an example. Harrison Schmidt, one of the astronauts participating in the mission, is a geologist. He not only guided other astronauts in geological exploration, but also personally retrieved highly valuable specimens from the moon. Although the United States has invested heavily in the manned lunar landing program, the value of the program's achievements in the past half century has reached at least six times the investment.
"The short-term benefits of manned lunar landing may be very low, but I think its long-term benefits are very high. Not to mention that the future lunar base must be based on manned lunar landing. From a scientific point of view, we should strive to achieve manned lunar landing." Yang Yuguang commented.
The space station cannot directly participate in the lunar mission
In 2021, the construction of China's space station has achieved great success. Can it help mankind carry out manned lunar landing activities? "The Chinese space station can play a role in the manned lunar mission, but it cannot directly participate in the lunar mission," Yang said
The space station operates in low earth orbit, about 400 kilometers away from the ground, and the orbit is relatively fixed. It is "far away" from the moon about 380000 kilometers away. It does not have the ability and necessity to act as a transit station. Moreover, the moon landing mission requires a high time window for rocket launch, and launching from the ground is a great challenge, not to mention launching from low earth orbit.
"Another reason why it is difficult for the space station to directly participate in the lunar landing mission is that the propellant of manned rockets, that is, fuel, cannot be stored in space for a long time. At present, the rockets that can be used for manned lunar landing missions use low-temperature propellants such as liquid hydrogen and liquid oxygen, which are difficult to be stored in space for a long time. This also determines that rockets used for manned lunar landing must be stored in space From the ground. " Yang Yuguang added.
However, although it cannot directly participate in the manned lunar mission, it does not mean that the space station cannot play other roles in the manned lunar mission. Yang Yuguang explained that the space station can serve as a test ground for many lunar exploration technologies. Carrying out scientific research experiments is one of the basic missions of the space station. When the manned lunar landing program needs to carry out technical experiments, the space station is naturally "duty bound". From this perspective, the space station will play an important role in the manned lunar mission.
"However, all space programs need rigorous demonstration and a large number of tests, as well as manned lunar landing. Dong also said that manned lunar landing also needs to tackle key technical problems and deepen the demonstration of programs, which is a necessary way." Yang Yuguang finally said.
(Science and technology daily)
