"Dongfang Hong, the Sun Rises", when this familiar song sounded in space, the world was shaken, and the blood in Chinese's heart boiled, and all this happened on April 24, 1970, on this day, China's first artificial satellite was successfully launched into the sky, and the Oriental Red Music resounded over the earth.
From this day on, China officially opened the satellite era, but also became the world's fifth country after the United States, the Soviet Union, France, Japan can produce and launch artificial satellites, the most valuable thing is that this satellite can be said to be completely dependent on the Chinese their own wisdom to create, in fact, the Dongfanghong I satellite is more valuable than the Renben Osumi satellite launched two months earlier, in order to be able to catch up with China, Japan changed the plan to launch a "simulation star", won the world's fourth place, But the satellite lost power after only 15 hours of operation after last day.
Although the launch of the Dongfanghong-1 satellite was two months late, it was definitely a fine product for a country that manufactured and launched satellites independently for the first time.
At that time, Dongfanghong No. 1 strictly adhered to the overall technical plan and goal of 12 characters, that is, to go up, to grasp, to hear, and to see. In the end, our scientific researchers overcame many difficulties, realized the perfect combination of missile technology and sounding rocket technology, and successfully sent the Dongfanghong-1 satellite into the earth's orbit. "Grasping" is to be able to grasp the position of the satellite in space and its distance from the ground at all times, and to do this, it is necessary to solve the problem of the satellite orbit equation, and the Chinese researchers have done it.
The so-called "listening" is naturally to make the oriental red music resound through space, and such a simple thing on the earth will become extremely difficult to put into space.
In order to achieve this goal, the researchers conducted hundreds of experiments, and finally replaced the "sound keys" with 6 sound source oscillators with high stability, and used the beat generated by the program-controlled line to control the pronunciation, and finally played "Oriental Red" in space. "Visible" is that after the satellite goes to the sky, it can be observed with the naked eye on the surface of the earth, which is also difficult, because the diameter of the Dongfanghong I satellite is only 1 meter, and its perigee point is at an altitude of 441 kilometers after the last day, the apogee is 1600 kilometers, and its brightness is at most equivalent to a seventh-magnitude star, while the naked eye can only see a sixth-magnitude star at most.
In order to make the Dongfanghong-1 satellite "visible", the researchers installed a large "observer" made of high reflective brightness materials that can be propped open like an umbrella in space, and with this observation body, the Dongfanghong-1 satellite suddenly rose from a seventh-magnitude satellite to a fourth-magnitude satellite, which is clearly visible to the naked eye on the earth.
As the first artificial satellite independently manufactured and launched by China, Dongfanghong I is not designed to live for a long time, only 20 days, and finally actually worked for 28 days, on May 14, 1970, Dongfanghong I finally stopped the transmission of signals because of the battery exhaustion, but the satellite did not go home, it is still in orbit on the Earth, it has been more than 50 years. So why hasn't the satellite fallen into Earth's atmosphere to this day?
The Dongfanghong-1 satellite operates in an elliptical orbit with a perigee of 441 km and an apogee of 1600 km, and at an altitude of 441 km, it is already the dispersion layer of the Earth's atmosphere, and the resistance to the movement of the satellite here is minimal.
As long as a satellite maintains a certain speed, it will not fall into the atmosphere because of the earth's gravity, and the resistance of Dongfanghong I is very small, so a little resistance is not enough to slow down the fall, so if there is no external force, it will also run in the earth orbit for many years. Of course, if we keep ignoring it, one day it will slow down and return to the embrace of the earth, but that will be a long time later, and you and I may not see it.
Why don't we take back the Dongfanghong No. 1?
First of all, dongfanghong satellite uses battery power supply, its battery has long been exhausted, so we have lost contact with it, even if we are not disconnected from it, we can not control it in any way. The Dongfanghong-1 satellite is a relatively simple satellite with no controllable equipment inside, so to recover such a satellite, it is only possible to launch another satellite to capture it, but being able to capture it does not mean being able to bring it back to the ground safely. Not only us, but now no country in the world has the ability to recycle satellites, but with the increase in the number of satellites in the earth's external space, this is a problem that human beings will face sooner or later. Because space in Earth's orbit is also limited, as the number of satellites increases, the danger factor of satellites will also increase, so everything left in space will one day have to be taken back.