Xinhua News Agency, Beijing, June 30 (Xinhua) -- Hu Hao, chief designer of the Chang'e-6 mission: In order to carry nearly 4 catties of soil on the back of the moon, I fought hard!
Xinhua News Agency reporters Wen Jinghua and Song Chen
At about 2 o'clock in the afternoon of June 25, in the Amugulang Grassland of Siziwangqi, Inner Mongolia, Hu Hao, the chief designer of the Chang'e-6 mission, finally welcomed back the "six girls" he had been concerned about for 53 days - the Chang'e-6 probe that realized the first sample return from the back of the moon.
Locate, search, check status...... The returner worked normally, the mission was a complete success, and Hu Hao's hanging heart was put down.
Although Chang'e-6 brought back nearly 4 catties of soil from the back of the moon as scheduled, Hu Hao is still on the go in the past few days: escorting the returner back to Beijing and opening the cabin to "take treasure", deploying and arranging follow-up expansion experiments of the orbiter, and witnessing the start of scientific research on samples from the back of the moon...... In between his busy schedules, he talked to Xinhua News Agency reporters for the first time about the unknown story of Chang'e-6.
"Six Girls" will bring new knowledge, "I am full of expectations"
The picture shows Hu Hao being interviewed by Xinhua News Agency. Photo by Xinhua News Agency reporter Wen Jinghua
The first lunar back sample of 1935.3 grams was collected, and the re-entry and return were more accurate than those of Chang'e-5, and the international payload harvested a "gift package" of scientific data...... Talking about the achievements of the "Six Girls", Hu Hao's face was full of pride and his voice was hearty.
"The Chang'e-6 mission is the most complex deep space exploration mission on the mainland to date, with many flight control events, compact links and complex control processes." Hu Hao said that the "Six Girls" adopted intelligent rapid sampling technology, and the actual work efficiency was about 30% higher than that of the "Five Girls". Based on the geology of the landing area and drilling operations, the final drilling sampling depth reached 1.1 meters.
The landing accuracy of the returner reflects the level of technical control of the mission. The Chang'e-6 returner has a landing point prediction accuracy of more than 10 meters, an umbrella opening point accuracy of more than 200 meters, and a landing accuracy of 16 kilometers, completing the last step home with high quality.
The four international scientific payloads carried by Chang'e-6 also gained a lot from this trip. Among them, the French radon gas detector sent back 158M scientific data, and the ESA lunar surface negative ion analyzer sent back 3.9M scientific data, both of which have entered the preparatory stage of post-data processing and paper publication;
"The international cooperation of the 'Six Girls' has also exceeded expectations, enhancing our international influence in the field of lunar exploration and promoting friendly exchanges with payload countries." Hu Hao said.
On June 28, the samples on the back of the moon were officially handed over to the Chinese Academy of Sciences, the leading unit of lunar scientific research, and Hu Hao could not hide his excitement: "What new knowledge will the 'six girls' bring?" I'm looking forward to it. ”
"Make the plan to the extreme" and look for certainty in uncertainty
On June 6, at the Beijing Aerospace Flight Control Center, Hu Hao (right), chief designer of the Chang'e-6 mission, and Guan Feng, director of the Lunar Exploration and Space Engineering Center, exchanged rendezvous and docking progress. Photo by Xinhua News Agency reporter Jin Liwang
Over the past three years, Hu Hao has led the team to carry out a large number of adaptation and optimization designs, and achieved three major technological breakthroughs, including the design and control of the lunar retrograde orbit, intelligent sampling on the back of the moon, and take-off and ascent on the back of the moon, making the Chang'e-6 mission the most technically advanced lunar exploration mission in China's aerospace history so far.
The biggest suspense is whether it will be able to accurately land in the predetermined area on the back of the moon. The map of the Moon is less accurate, with a maximum resolution of only about two meters, and because there is no real-time image data on the far side of the Moon, it can only be judged by telemetry data.
The sampling process is like "opening a blind box". Since it is impossible to determine the state under the moon surface in advance, it is necessary to design drillthrough and table fetch as "mutual backups". In case the drilling does not work, the cost of moving the position is very high, and it is necessary to "guarantee" the bottom by taking the table.
"The reliability of the Chang'e-6 mission is a product relationship, one link is 0.9, and another link is 0.9, and the reliability of the entire system is reduced to 0.81." Looking back, it is already light and light, but it sounds thrilling everywhere.
For example, the implementation of unmanned sampling, packaging, and transfer on the back of the moon requires high precision and difficulty, and the vacuum of the moon is very high, and entering a little atmosphere may pollute the sample, the research and development team conducted a large number of experiments on the ground simulation platform to ensure that the sample is consistent with millimeter-level accuracy.
"We have taken the plan to the extreme, looking for certainty in the uncertainty, even if the relay satellite fails, Chang'e-6 can still carry out sampling and take off autonomously." Hu Hao said, making a gesture, clean and neat, without redundancy.
Accompanying "Chang'e" all the way to grow up, "astronauts have thrown themselves into new battles"
On June 4, at the Beijing Aerospace Flight Control Center, Hu Hao (left), chief designer of the Chang'e-6 mission, Li Dong, chief designer of the Long March 5 launch vehicle, and Wang Qiong (front), deputy chief designer of the Chang'e-6 mission, exchanged the progress of the Chang'e-6 mission. Photo by Xinhua News Agency reporter Jin Liwang
In 2007, the Chang'e-1 probe, based on an Earth-orbiting satellite, weighed only 2.35 tons, and in 2024, the Chang'e-6 mission will send a probe weighing more than 8 tons to the moon. Over the past 17 years, China's ability to enter space has been improved by leaps and bounds.
Growing up with "Chang'e" all the way, Hu Hao has experienced several identity changes from deputy commander-in-chief to chief designer, but what remains unchanged is that "he is always facing new problems and meeting new challenges".
Extraterrestrial objects are sampled and encapsulated, and the lunar orbit is unmanned rendezvous and docking, and re-entry and return at near-second cosmic velocity...... In 2020, with Hu Hao as the chief designer, the Chang'e-5 mission created a number of "Chinese firsts" and achieved a large technological leap.
"It's not scary to open the door and see tigers and poisonous snakes, you can find a way to deal with them; The scary thing is that it is dark outside the door, is this step or not? Hu Hao used a vivid metaphor to express the great pressure and challenge of moving towards the unknown.
One innovation breakthrough after another, breaking through the barriers again and again, Hu Hao summed up his feelings along the way with four "letters"——
"Only with firm belief can we sharpen our swords for ten years and move forward towards a common dream; Only by maintaining confidence can we face difficulties and achieve breakthroughs in the face of new challenges; Only by trusting each other can we unify the pace and work together in the complex large-scale system project; Only by keeping our words can we make relevant units at home and abroad willing to cooperate with us. ”
A manned landing on the moon will be achieved by 2030, and a basic international lunar research station will be built by 2035...... The blueprint for the future has been drawn.
"Chang'e-5 and Chang'e-6 prove that this technical route to and from the moon designed by the Chinese is feasible." Hu Hao's tone was confident and decisive, "The astronauts have entered a new battle!" ”