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After 52 years, Dongfanghong No. 1 is still flying in the sky?
April 29, 2022 19:09 6256 times reading source: qubit 2 comments
Unexpectedly, 52 years later, the Dongfanghong-1 satellite is still flying in the sky? ! If it hadn't been photographed, I honestly wouldn't have believed it. Just a few days ago, a video of "The Same Frame of the Century" made netizens collectively break the defense: In the video, the "Dongfanghong-1" satellite passed by the Chinese space station and launched two artificial celestial bodies with a difference of nearly half a century. "Seeing each other from a distance" in the night sky.
△ Source: Tencent Video
Some netizens lamented the miracle of the gathering of two "stars" separated by half a century:
But what surprised more netizens is that "Dongfanghong No. 1" is still in the sky:
After all, the first artificial satellites launched by the United States, the Soviet Union and Japan at the same time have all crashed due to various reasons such as orbit and power.
The significance of "Dongfanghong-1" itself does not need to be repeated. It is my country's first artificial satellite. As the "one star" in the "two bombs and one star", it carries the dreams and original aspirations of generations of astronauts.
The launch of "Dongfanghong No. 1" marks the beginning of China's exploration of space.
After that, my country's aerospace development has "opened branches and scattered leaves" --
Sun Jiadong , chief designer of the "Dongfanghong No. 1" satellite , became the first chief designer of China's lunar exploration project, opening the way for China's lunar exploration and deep space exploration;
Qi Fazhen , one of the technical leaders of the "Dongfanghong No. 1" satellite , served as the chief designer of the Shenzhou spacecraft, and China began to write history in manned spaceflight;
Chen Fangyun , chief designer of the "Dongfanghong No. 1" satellite measurement and control system , became one of the founders of the Beidou satellite navigation system;
But in fact, this "Dongfanghong-1" satellite, which has been flying in space for 52 years, was originally developed on the basis of "nothing" from theory to industry.
More than 5,000 people, on the basis of 200 million yuan of funds, used a pen and an abacus to "manually" complete the whole process of satellite design, production, manufacturing and launch step by step.
For the first time in the universe, there is a voice from China
In 1970, there was a voice from China for the first time in the universe——
China's first artificial satellite , Dongfanghong-1, was successfully launched, ushering in a new era in China's spaceflight history.
It was named "Dongfanghong No. 1" because the satellite sent the song "Dongfanghong" to the world in space.
It weighs 173 kilograms, is a spherical polyhedron with a diameter of 1 meter, and is equipped with four whip antennas of 3 meters long.
After lift-off, the satellite orbits the earth for 114 minutes, and transmits telemetry parameters and scientific detection data while playing the music "The East is Red" with a frequency of 20.002 MHz.
Today, the annual China Space Day is set on April 24, the day of the launch.
But looking back at the development of Dongfanghong-1 from 0 to 1 at that time, everything was not easy.
In the late 1950s, China officially proposed to do artificial earth satellites.
Before that, the Soviet Union had successfully launched the world's first artificial satellite. The United States followed, sending Explorer 1 into space in 1958.
At this time, China is still far from the conditions for launching satellites in terms of economy and talents.
Even at the tenth anniversary presentation in 1959, the models of satellites and rockets on display were hand- typed by young scholars.
According to CCTV, these young people's knowledge of rockets and satellites at that time was not as good as that of today's middle school students .
And even if the model is made, there are still a lot of practical problems that cannot be solved, such as the inability to choose design parameters, poor test conditions, and insufficient supply of required production and processing equipment...
It is not that Chinese scientists have not thought about learning from their big brother, the Soviet Union, and they even went to Moscow to investigate, but the results were helpless.
And because of the limited national strength, they decided to lay the foundation first and devote themselves to the research and development of rockets, high-altitude physical detection and other equipment.
Until the successful launch of the Dongfeng-2 medium-range missile, China basically has the ability to launch artificial earth satellites.
Under the leadership of Qian Xuesen, Zhao Jiuzhang and others, the development of the Dongfanghong-1 satellite was officially put on the agenda.
https://static.cnbetacdn.com/article/2022/0429/1a9a4b7ac6cf1cf.jpg
△ Source: Xinhuanet, Music Installation
They also set up a flag with a higher starting point: China's first satellite should be around 100 kilograms .
At that time, the Soviet Union's first satellite weighed 83.6 kilograms, and the first American satellite was only 8.2 kilograms. The heavier the satellite, the higher the requirements for the rocket engine and equipment.
But in the end they were done, and the actual weight was 173kg.
It was not until February 20, 1968, that the China Academy of Space Technology was established, and the development of Dongfanghong-1 was officially put on the agenda——
Qian Xuesen served as the first dean, with a research and development team of more than 5,000 people, and the central government allocated 200 million yuan .
△ Qian Xuesen
According to Xinhuanet, Pan Houren , deputy head of the overall design team for the "Dongfanghong-1" satellite, recalled:
200 million RMB was not easy at that time.
Because apart from funding, the older generation of astronauts have almost nothing.
Many difficulties during the period were solved by the "earth method".
For example, riveting is an important process in satellite manufacturing , because the satellite factory was converted from a scientific instrument factory at that time, and it has never done this, and there are no riveting guns and trusses for fixing workpieces.
The workers rely on a small hammer and use their own bodies as trusses to knock the rivets up one by one.
Under these conditions, they solved a number of process problems, and then came to various stages of environmental simulation experiments.
Qi Fazhen , one of the technical leaders of the "Dongfanghong No. 1" satellite, once recalled that during the summer test, because the satellite factory did not have a low-temperature laboratory, he wore a large cotton jacket and went to the Navy's cold storage for the test.
△ Source: Cosmic Song "The East is Red"
The conditions are tougher, but the technology is constantly iterating .
On the eve of the establishment of the Institute in 1967, Dang Hongxin , the pioneer and academic leader of China's tribology discipline, and his team solved a key problem of satellite transmission.
They chose a copper-based conductive dry film and successfully solved the problem of difficult signal transmission for ultrashort-wave antennas at -100°C to 100°C.
The reason why the earth can receive the music signal of Dongfanghong No. 1 is due to the credit of Dang Hongxin's team.
△ Video source: Universe Song "The East is Red"
The signal problem is solved, but the satellite itself has to withstand extreme temperature changes.
At that time, this was still a problem recognized by the world.
To this end, Chinese scientists have developed a complete temperature control system to balance the temperature inside the satellite, but the normal operation of the system requires a lot of power, and the power carried by the satellite is very limited.
Finally, they thought of using the heat generated by other instruments during operation to help the satellite control the temperature. The external material is made of aluminum alloy material treated according to temperature control, which solves the problem of high power consumption.
Soon after two or three years, they completed the goal of the first artificial satellite.
On April 24, 1970, the Long March-1 carrier rocket carried the Dongfanghong-1 satellite successfully into the predetermined orbit, completing a more than 20-day exploration mission, and stopped transmitting signals on May 14 of the same year.
China has thus become the fifth country in the world to independently develop and launch satellites.
From the official project establishment to the successful launch of the satellite, China has completed it in less than five years.
And to this day, Dongfanghong is still flying in space, overlooking the development of China's aerospace. Most of the satellites of the same period have fallen into the atmosphere.
How exactly is this done?
Why is Dongfanghong-1 still in orbit?
We have to start with the entire technical solution at that time.
At that time, the Dongfanghong-1 satellite was designed, and the main task was to conduct satellite technology experiments, detect the ionosphere and the density of the atmosphere.
Therefore, in the orbit design, it is a near-Earth elliptical orbit with a perigee of about 441 kilometers and an apogee of about 2368 kilometers, which forms an angle of 68.5 degrees with the earth's equatorial plane.
We know that satellites do not need power to fly around the earth in space, and they fly completely by inertia. In theory, if there is no resistance, there is no energy consumption and it will fly forever.
But in fact, space is not empty, especially in the low-Earth orbit of the earth, there are still traces of gas. The closer to the earth, the more gas molecules, which is why the space station is actively raising its orbit every once in a while. reason.
As we mentioned above, Dongfanghong-1 runs on an orbit with a perigee of 441 kilometers and an apogee of 2368 kilometers.
For comparison, the International Space Station currently operates in an orbit at an altitude of 420 kilometers. It can be seen that even the perigee of Dongfanghong-1 is higher than the orbit of the International Space Station. Therefore, the resistance of Dongfanghong-1 in orbit is very small.
As for another more common destination - entering the atmosphere (about 100 kilometers to 300 kilometers), burning and disintegrating, it also has to wait for the year of the monkey and the month of the horse.
According to the latest data, the most recent altitude of the Dongfanghong-1 satellite is 428 kilometers, and the altitude of the apogee is 2030 kilometers.
That is to say, after half a century of operation, the perigee of Dongfanghong-1 is only lowered by 13 kilometers.
However, it is not easy to launch a satellite in such a high orbit. At first, the theoretical basis of the "Long March 1", the Dongfeng-4 missile, did not have the power to launch the satellite to an altitude of more than 400 kilometers.
Therefore, "Long March No. 1" has been greatly optimized on the basis of Dongfeng No. 4, including upgrading the rocket to the third stage... and finally successfully sent Dongfanghong No. 1 to the designated orbit.
The success of this mission has also laid a solid foundation for the development of my country's subsequent aerospace technology.
Half a century of China's aerospace road
The launch of the "Dongfanghong-1" satellite has ended, and China's space journey has just begun.
In the next 50 years, the scientists who initially participated in the "Dongfanghong-1" satellite project, with the space technology they explored, went into more complex fields and completed one impossible task after another——
From manned spaceflight , to lunar exploration and deep space exploration missions, step by step toward the sea of stars.
Wang Xiji , who proposed the technical plan of the "Long March 1" carrier rocket to carry the Dongfanghong-1 satellite to the sky, and organized the development of it , once again supported China's first "returnable satellite" after the Dongfanghong-1 mission ended. The burden of the chief designer.
In 1975, my country's first returnable satellite was successfully launched and recovered, successfully taking the first step in manned spaceflight.
After that, Chen Fangyun , chief designer of the satellite measurement and control system of "Dongfanghong No. 1" , and his collaborators jointly proposed a "dual-satellite positioning system", which has become an important theoretical basis for the Beidou satellite navigation system;
Qi Fazhen , one of the technical leaders of the "Dongfanghong No. 1" satellite , was appointed as the chief designer of the Shenzhou spacecraft. A total of four unmanned spacecraft tests were conducted before and after, as well as countless ground tests.
In 2000, two Beidou navigation experimental satellites were successfully launched, and China finally had its own satellite navigation system.
In 2003, "Shenzhou V" carried Yang Liwei successfully to the sky, China's first real manned space flight mission.
Hu Shixiang , the "Launch General" who was in charge of launching the "Dongfanghong-1" satellite , also served as the deputy commander of China's manned spaceflight project at that time, and witnessed the historical process of China's launch of the first satellite to the successful manned spaceflight. .
In the same year, Sun Jiadong , chief designer of "Dongfanghong No. 1", became the chief designer of China's lunar exploration project, further extending China's aerospace dream from low-Earth orbit.
In 2007, my country's first lunar exploration satellite "Chang'e-1" was launched and successfully entered the orbit around the moon and flew around the moon. my country officially started the era of lunar exploration.
In 2008, "Shenzhou VII" was launched into space and entered a predetermined orbit. Chinese astronauts achieved spacewalking for the first time and mastered the technology of space exit activities.
In 2017, Tiangong-2 and Tianzhou-1 completed the rendezvous and docking, an important step in the construction of China's space station; in 2020, the "Chang'e-5" probe was launched and successfully returned with lunar samples; the same year, the Beidou-3 global satellite navigation system Officially opened...
Just a few days ago, a video of Dongfanghong-1 and the Chinese space station "in the same frame" detonated the entire Internet.
It was shot by Zhu Jin, a researcher at the Beijing Planetarium and editor-in-chief of "Astronomy Enthusiasts" magazine, and Wang Zhuoxiao, a Ph.D. in astrophysics at Tsinghua University.
△ Left is Zhu Jin, right is Wang Zhuoxiao
This day happened to be April 24, the launch date of the Dongfanghong-1 satellite, which was also Zhu Jin's birthday. Every year on this day, he would go to see if the Dongfanghong No. 1 transited the border.
△ At the time of shooting (authorization: Qiao Hui)
In the first two days, Zhu Jin also happened to take a photo of the China Space Station (Tiangong Space Station) and Dongfanghong-1 in the same frame.
In the photo, the trajectories of Dongfanghong-1 and the Chinese space station are jointly fixed in the night sky, which is also called the legendary "century in the same frame" by netizens.
When talking about the progress and impact of my country's space exploration in recent years, Zhu Jin sighed:
In recent years, China's deep space exploration, lunar exploration, and manned spaceflight have made a lot of progress, which has also influenced some children to pay attention to the stars and possibly astronomy.
Looking forward to the development of my country's aerospace technology better and better.
