Beidou, which can compete with GPS, has completely independent core components. How was it born in the blockade?

On June 23rd, 2020, a rocket was launched in xichang satellite launch center, carrying the 55th Beidou navigation satellite into space. The camera recorded the real process of satellite solar panels unfolding in space.

This is the last launch of Beidou-3 satellite global networking. It took China 26 years to independently build a global satellite navigation system.

Time came 1990, and the Gulf War that shocked the world started. For the first time, the GPS positioning system in the United States achieved great success in the form of weapon guidance. In the summary report, Americans attributed the Gulf War to the victory of GPS, and China and the world felt the importance of owning navigation satellites from this war. Finally,1February 1994, China decided to officially launch the Beidou satellite project. This year, it is already.

Both the United States and Russia have chosen a one-step mode to build navigation systems, but Beidou's early technology and talents are very scarce, so China chose a three-step development mode according to the actual situation:

In the first step, Beidou-1 served China and achieved a breakthrough in regional satellite positioning.

In the second step, Beidou-2 covers the Asia-Pacific region and realizes comprehensive functions such as positioning and navigation.

The third step, Beidou-3, is to realize global networking and serve the whole world.

In June, 2000, at the request of China and the European Union, the United Nations Telecommunication Union squeezed out the last short frequency from the aviation navigation band for all countries in the world to apply equally. According to the international rules of first come, first served and expired, the time limit for applying for frequency activation is seven years, which means that China must launch a satellite and successfully broadcast the signal before April 17, 2007, otherwise everything will come to nothing, and the newly started Beidou-2 will also be wasted. We must race against time. In 2005, the first Beidou-2 satellite has entered the most intense production stage, but there is still a gap between the on-board atomic clock for satellite and the demand. Atomic clock provides time and frequency reference for navigation satellites, and is an important core component that determines the positioning and timing accuracy of satellites. The four atomic clocks loaded on the first satellite of Beidou-2 adopted the configuration scheme of 1 domestic 4. However, in the international market at that time, almost all high-tech products such as on-board atomic clocks were banned from entering China by western countries. After negotiation, only one European company is willing to sell them to China, but it is not just the price. On the last day of May, 2005, the Beidou-2 team finally decided that all four atomic clocks of the first satellite were made in China. At this time, it was less than two years since the launch of Beidou-2, and the frequency band remained. Previously, the domestic atomic clock, which was only used as a backup, turned positive overnight, which means that a technological breakthrough will be achieved within one and a half years to produce China's own on-board atomic clock.

In September 2006, after overcoming a series of technical difficulties, the on-board atomic clock truly belonging to China was successfully developed. On April 14, 2007, the first Beidou-2 satellite was launched. However, according to the rules of ITU, only signals transmitted from satellites are considered as valid frequencies. In order to maintain the frequency, the satellite must return the signal within 88 hours until 8 pm on April 17. Finally, after more than 80 hours of launch, Beidou-2 sent back a clear signal. At this time, the deadline set by ITU is less than 4 hours. Almost at the last moment when the door was about to be completely closed, China squeezed into the Global Satellite Navigation System Club.

Starting from 20 17 1 1, Beidou-3, as the last step of China's three steps, began to make rapid progress towards the ultimate goal. In the following 32 months, China launched 32 Beidou satellites at the rate of one satellite per month with a success rate of 100%, setting a new record for the networking launch of navigation satellites in the world.

On June 23, 2020, the last satellite of Beidou system was launched to realize global networking. So far, China has spent 26 years, invested more than 654.38+0.2 billion dollars, and launched 59 satellites into space.