Chapter 161 Your senior brother's thinking speed and height are beyond the reach of ordinary people
"We are not completely sure whether we can get it done." Huang Zongsheng said in the video screen: "The project goals do face huge challenges, but in the end we can achieve the expected goals. 70% of it is fine. For example, the gold coating process does not necessarily have to be 60 nanometers,
100 nanometers is also acceptable. ”
Obviously, this is a very high goal, but it does not have to be achieved.
Set a high goal to put pressure on the R&D team.
Hearing this, Lu An nodded and said, "Okay, I support this plan, let's do it first."
For a telescope, the larger the mirror, the more light it can capture and the higher the resolution of the image obtained. The main mirror of the "Lu'an Telescope" consists of 36 hexagonal lenses to form a mirror with a diameter of 8.8 meters.
The surfaces of these 36 lenses all need to be coated with an ultra-thin layer of gold, because gold best reflects infrared light, with a reflectivity of over 98%
h.
The core technical challenge is ultra-high precision manufacturing. For example, the primary mirror system requires ultra-low temperature optical engineering with nanometer precision.
The design is to use beryllium base material and gold coating. The main mirror is assembled from 36 hexagonal beryllium mirrors. Beryllium metal is chosen because it has both lightweight, high stiffness and thermal stability at -240°C.
The gold coating process requires evaporating a 60-nanometer gold layer on the mirror surface, which is equivalent to one-thousandth of the thickness of a human hair.
To improve the reflectivity in the infrared band, the coating needs to be completed in a vacuum environment at 1371°C, and the thickness error needs to be controlled at the atomic level.
The surface roughness of each lens should be less than 7 nanometers, which is equivalent to the width of only 20 beryllium atoms, and the overall deformation tolerance after splicing should be less than or equal to 7 nanometers.
It can be said that if this telescope can be successfully manufactured, it will be the most sophisticated and complex space astronomy hardware facility created by mankind to date.
Lu An himself definitely doesn't have time to lead a team to build this telescope. He has a lot of things to be busy with.
However, he can give some theoretical ideas. Lu An plans to provide them with some ideas and directions in the four main environments of material science, precision manufacturing, cryogenic engineering, and on-orbit deployment based on their design goals.
Once the ideas are in place, let them spend five to ten years working on it, and they should be able to achieve the plan goals.
Lu An's ability relies on talent and experience. It is the memory knowledge accumulated over hundreds of years in his previous life, which allows him to have a high degree of mastery of the entire knowledge system.
Next, I discussed with Huang Zongsheng which orbital position it would be better to send the "Lu'an Telescope" to.
Lu An said without hesitation: "Since it focuses on the infrared band, this telescope must be deployed at the L2 point of the sun and the earth. Only this location is the most suitable. It can effectively block the thermal radiation of the sun and the moon and maintain an ultra-low temperature environment."
Huang Zongsheng said in the video: "The L2 point is indeed the most suitable orbital position for the telescope. We have also discussed it, but the question is, can our rocket technology send the telescope to a position of 1.5 million kilometers? This is a big problem. Our rocket has never had the ability to send such a distance."
The farthest distance that China's current space vehicles can reach is the moon, and the distance between the earth and the moon is less than 400,000 kilometers.
There was a "Yinghuo 1" Mars exploration project five years ago, but it was sent there using Big Goose's rocket, and this deep space exploration project in cooperation with Big Goose also failed. This failure hindered the original plan to reach Mars in September 2012, and the joint Mars exploration project of both parties was also frustrated.
The so-called L2 point is the Sun-Earth Lagrangian L2 point. It is located on the extension line of the Sun-Earth connection, about 1.5 million kilometers away from the Earth. It is a special position where gravity and centrifugal force are balanced.
Lu An smiled confidently: "It is true that we don't have this capability now, but that doesn't mean we won't have it in the future. Teacher, when you get the telescope, the Astral Power Spaceflight will definitely have the ability to send it to the L2 point by then. Don't worry, I guarantee it."
After some discussion between the two, the orbit of the "Lu'an Telescope" was determined to be at the sun-Earth L2 point.
At this time, Lu An turned back to Meng Qiuyan and said, "Bring me a whiteboard."
After a while, Meng Qiuyan brought a 20-inch whiteboard and handed it to Lu An, who quickly took a pen and wrote some formulas on it,
and drew some corresponding orbit sketches.
Then face the whiteboard towards the video camera.
Lu An immediately said: "The general process is that the rocket sends the telescope into a highly elliptical transfer orbit. The orbit design can allow the telescope to gain enough kinetic energy to push towards the L2 point. Of course, it has not completely escaped the gravitational constraints of the earth."
Then he added: "After the launch, some corrections need to be made midway. Use the spaceborne thruster to adjust the velocity vector and send it accurately into the halo orbit around the L2 point."
The first is to protect the extreme low temperature environment. The L2 point is located on the side of the earth facing away from the sun, 1.5 million kilometers away from the earth.
The telescope's sunshade can completely shield the thermal radiation from the sun, the earth and the moon, allowing the telescope to maintain an extremely low temperature state. This is the key to achieving high-sensitivity observations in the infrared band.
If it is placed in a low-Earth orbit like the Hubble Telescope, the infrared radiation of the Earth will completely drown out the target observation signal.
Secondly, it has an unobstructed continuous observation window. At the L2 point, the telescope can avoid the shadows of the earth and the moon at the same time, achieving continuous observation of 50% of the sky area. It can gradually cover the entire sky area through half-yearly orbits.
In contrast, the Hubble Telescope passes through the Earth's shadow every 90 minutes, which limits its observation efficiency.
Finally, there is a stable thermal and dynamic environment. The halo orbit keeps the telescope in constant sunlight conditions, avoiding damage to precision optical system components caused by frequent day and night temperature differences in low-Earth orbit.
At the same time, the gravitational balance characteristics of the L2 point make the fuel required to maintain the orbit only one-quarter of that of a low-Earth orbit satellite, which can significantly extend the operational life of the telescope.
It can be guaranteed to be used for at least 30 years.
Huang Zongsheng said solemnly: "The thermal control technology of the sun visor. The sun visor composed of seven layers of polyimide film can reflect more than 99.98% of solar radiation. The temperature of the sunny side is 358K and the temperature of the shady side is only 6K. Its temperature gradient design needs to break through. The limit of existing space vehicle thermal control technology. ”
According to what you said, the radius of the telescope’s halo orbit will reach 800,000 kilometers. This may be the first time that humans have deployed such a large-scale scientific facility at the L2 point. Its orbital parameters need to accurately balance the gravitational effects of the sun, earth and moon, while avoiding the effects of space weather events such as coronal mass ejections.
Hearing this, Lu An smiled and said: "The problem is not big. I already have an idea. It can be solved through autonomous navigation capabilities. The distance from the earth is too far, so the telescope can only have highly autonomous orbit correction capabilities."
Lu An thought for a while and added: "At that time, the space-borne computer equipped with the telescope can solve the three-body gravitational equation in real time, and dynamically adjust the propulsion strategy based on the ranging data of the deep space network." Huang Zongsheng, who was far away at NPU, chatted with Lu An online for so long, and he increasingly felt that if Lu An could participate in the development of the "Lu An Telescope", many technical challenges would probably not be difficult.
However, before Lu An expressed that he did not have that much time, Huang Zongsheng did not say anything, after all, he paid for it.
Furthermore, Huang Zongsheng already knew that Lu An had solved the Navier-Stokes equation problem. At this time, many engineering projects and national project engineering units in a series of industries were waiting for Lu An to develop the star stream tool.
Unfortunately, until now, no one has understood Lu An’s paper.
Huang Zongsheng had also read the paper a long time ago, but did not understand it.
At this time, whether those engaged in theoretical physics or mathematics, Lu An's paper drove them crazy.
At this stage, the Xingliu tool can only be developed by Lu An alone. There really is not much time. The project engineering units are all waiting online, and each one is more urgent than the last.
If this tool can be used early, billions or even tens of billions of investment budgets can be saved, as well as several years or even ten years of time costs.
So everyone is waiting, and would rather wait another two or three years.
After about five minutes, the video connection ended.
Lu An sat in front of the screen and thought for a while, then started to write on the manuscript with a pen.
Meng Qiuyan left the room without disturbing him.
Twenty minutes later, Lu An wrote down the theoretical essence of the four core aspects of the Lu An telescope's material technology, precision manufacturing, cryogenic engineering, and on-orbit deployment on four pages of A4 paper.
He himself didn’t have much time and energy, so he pointed out the direction.
Lu An scanned it again after writing to confirm that there were no problems, and then faxed the four pages of the manuscript to Huang Zongsheng.
It might take an ordinary scientist several years or even decades, but Lu An was able to sort out the core issues in an afternoon tea,
and provide specific and reliable ideas.
“Teacher, this is the fax information sent by Senior Brother Lu.” One of Huang Zongsheng’s student assistants came over with a four-page manuscript document and handed it to him.
Hearing that it was the manuscript sent by Lu An, Huang Zongsheng immediately put down what he was doing, took the manuscript, put on his glasses and began to read it carefully. The student soon saw that his tutor became more and more excited, and couldn't help but curiously asked: "Teacher, what did Senior Brother Lu write that made you so excited?"
He had just read it himself, but he was put off by the complicated formulas and theories at the first page.
The individual words and symbols in it can be understood individually, but cannot be understood together.
At the end, Huang Zongsheng took off his glasses. He regarded the contents of these four pages as treasures and said with great excitement: "Wonderful! It's so wonderful!"
Huang Zongsheng turned to look at the students standing aside and said: "The four-page manuscript sent by your senior brother is enough to become the cornerstone of our country's development of space telescopes, especially cryogenic engineering, material technology, etc. It has proposed technical theories from scratch." "
The student standing next to him was shocked and said: "It's just a four-page manuscript, how can it be so outrageous?"
Huang Zongsheng glanced at the four pages in his hand and paused for a moment. He thought slowly and said, "I just ended the remote connection with him twenty minutes ago. He should have written these four pages of manuscript within twenty minutes. The content here is enough for mediocre scholars like us to study for several years or even ten years."