The immigration police and the space station are in the same box.

Reviewer: Ada, Center for Space Application Engineering and Technology, Chinese Academy of Sciences.

Unexpectedly, 52 years later, Dongfanghong-1 satellite is still flying in the sky? !

If someone hadn't really filmed it, to be honest, I still couldn't believe it.

Just a few days ago, a video of "Century in the Same Box" let netizens collectively break the defense:

Source: Tencent Video

In the video, the "Dongfanghong-1" satellite passed by the China Space Station, and two artificial celestial bodies with a difference of nearly half a century were launched in the night sky.

Some netizens lamented the miracle that two "stars" separated by half a century met:

After all, the first artificial satellite launched by the United States, the Soviet Union and Japan at the same time has crashed due to various reasons such as orbit and power.

The meaning of "Dongfanghong No.1" itself needs no elaboration. This is China's first artificial satellite. As a "satellite" in the "two bombs and one satellite", it carries the dreams and initial intentions of several generations of astronauts.

The launch of Dongfanghong-1 marks the beginning of China's exploration of space.

Since then, China's space development has been "flourishing"-

Sun Jiadong, chief technology officer of Dongfanghong-1 satellite, became the first chief technology officer of lunar exploration project in China, which opened the road of lunar exploration and deep space exploration in China.

Qi Faren, one of the general directors of "Dongfanghong-1" satellite technology, served as the general director of shenzhou spaceship technology, and China began to write history in manned space flight;

Chen Fangyun, chief technology officer of the "Dongfanghong-1" satellite measurement and control system, became one of the founders of 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 almost nothing from theory to industry.

More than 5,000 people completed the whole process of satellite design, production, manufacture and launch step by step with pens and abacus on the basis of 200 million yuan.

For the first time in the universe, a voice from China appeared.

1970, the voice from China appeared for the first time in the universe-

The successful launch of China's first artificial satellite, Dongfanghong-1, opened a new era in China's space history.

It was named "Dongfanghong-1" because this satellite sang "Dongfanghong" to the whole world in space.

Weight 173kg, spherical polyhedron, diameter 1m, equipped with four whip antennas with a length of 3m.

After the satellite is launched, its orbital period is 1 14 minutes. While playing the music Dongfanghong at the frequency of 20.002 MHz, it also transmits telemetry parameters and scientific detection data.

Today, the annual China Aerospace Day is designated as the launch day-April 24th.

But looking back on the development of Dongfanghong-1 from 0 to 1, everything is so difficult.

In the late 1950s, China formally proposed to be an artificial earth satellite.

Prior to this, the Soviet Union had successfully launched the world's first artificial satellite. The United States followed suit and sent Explorer 1 into space in 1958.

At this time, China, in terms of economy and talents, is far from having the conditions for launching satellites.

Even in the tenth anniversary of 1959, the satellite and rocket models exhibited to the outside world were knocked out by young scholars.

According to CCTV, these young people didn't know rockets and satellites as well as middle school students now.

Moreover, even if the model is made, there are still many practical problems that cannot be solved, such as the selection of design parameters, poor test conditions and the lack of supply of required production and processing equipment. ...

Scientists in China didn't want to learn from their big brother, the Soviet Union, and went to Moscow to investigate, but they were left out in the cold.

Moreover, due to the limited national strength, they decided to lay the foundation first and devote themselves to the research and development of equipment such as rockets and high-altitude physical exploration.

It was not until Dongfeng -2 medium-range missile was successfully launched that China basically had the ability to launch artificial earth satellites.

Source: Xinhuanet, music installation

They also set up a flag with a higher starting point: China's first satellite should be around 100 kg.

At that time, the first Soviet satellite weighed 83.6 kilograms, while the first American satellite weighed only 8.2 kilograms. The heavier the satellite, the higher the requirements for rocket engines and equipment.

But in the end, they finished, and the actual weight reached 173 kg.

It was not until1February 20th, 968 that China Academy of Space Technology was established that the development of Dongfanghong-1 was officially put on the agenda.

Qian Xuesen served as the first dean, with a research team of more than 5,000 people and a central allocation of 200 million.

Qian Xuesen

According to Xinhuanet, Pan Houren, deputy head of the overall design team of Dongfanghong-1 satellite, recalled:

200 million RMB was really not easy at that time.

Because apart from funding, the older generation of astronauts have almost nothing.

Many difficulties during this period were solved by "indigenous methods".

For example, riveting is an important process in satellite manufacturing, because the satellite factory was rebuilt by scientific instrument factory at that time, and there were no riveting guns and trusses to fix the workpiece.

Workers rely on a small hammer, use their bodies as trusses and knock rivets one by one.

Under this condition, they solved many technical problems and then entered many stages of environmental simulation tests.

Qi Faren, one of the technical directors of the "Dongfanghong-1" satellite, once recalled that during the summer experiment, because there was no low-temperature laboratory in the satellite factory, he went to the navy's cold storage to do experiments in a big cotton-padded jacket.

Source: The universe sings "Dongfanghong"

The conditions are a bit tough, but the technology is always iterative.

On the eve of the establishment of 1967 research institute, the pioneer and academic leader of tribology in China solved a key problem of satellite transmission together with the team.

They chose a conductive dry film based on copper and successfully solved the signal transmission problem of ultrashort wave antenna from-100 to 100.

Hong Xin's team contributed greatly to the earth's reception of the music signal of Dongfanghong-1.

Video source: The universe sings "Dongfanghong"

The signal problem has been solved, but the satellite itself has to withstand the test of extreme temperature changes.

At that time, it was an internationally recognized problem.

Therefore, 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 electricity, and the amount of electricity carried by the satellite is very limited.

Finally, they thought of using the heat generated by other instruments to help the satellite control the temperature. Its external material is aluminum alloy treated by temperature control, which solves the problem of high power consumption.

Soon after two or three years, they accomplished the goal of the first artificial satellite.

1On April 24th, 970, the Long March-1 carrier rocket successfully entered the scheduled orbit with Dongfanghong-1 satellite, completing the exploration mission for more than twenty days, and stopped transmitting signals on May 4th of the same year.

China has thus become the fifth country in the world to independently develop and launch satellites.

It took China less than five years to complete the project from the formal establishment to the successful launch of the satellite.

Today, Dongfanghong is still soaring in space, overlooking the development of China's space flight. Most of the satellites in the same period have fallen into the atmosphere.

What the hell is going on here?

Why is Dongfanghong-1 still in orbit?

We have to start with the whole technical scheme at that time.

At that time, Dongfanghong-1 satellite was designed, and its main task was to carry out satellite technology experiments to detect the ionosphere and atmospheric density.

Therefore, in orbit design, it is an elliptical orbit near the earth, with perigee of about 44 1 km and apogee of about 2368 km, making an angle of 68.5 degrees with the equatorial plane of the earth.

As we know, satellites fly around the earth in space without power, and they fly entirely by inertia. Theoretically, if there is no resistance, there will be no energy consumption and it will fly forever.

But in fact, space is not empty, especially there are still traces of gas in the near-earth orbit. The closer to the earth, the more gas molecules there are, which is why the space station will actively upgrade its orbit every once in a while.

As mentioned above, Dongfanghong-1 runs in the orbit with perigee of 44 1 km and apogee of 2368 km.

In contrast, the International Space Station is currently operating in a 420-kilometer-high orbit. As a result, 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 km ~300 km) and burning and disintegrating, it will take a long time.

According to the latest data, the latest perigee height of Dongfanghong-1 satellite is 428 kilometers, and the apogee height is 2030 kilometers.

In other words, after half a century's operation, the perigee of Dongfanghong-1 only decreased by 13km.