From Iridium to Starlink, is satellite Internet coming?

  On September 17, the Shenzhou 12 return module landed safely at the Dongfeng Landing Site, marking the successful conclusion of the 90-day manned space mission. The Tianzhou-3 cargo spacecraft was also launched on September 20 to bring all kinds of materials needed for the next manned mission to the Tiangong space station.
  The intensive launch plan of the Tiangong space station is inseparable from a complete “low-latency” air-space-ground integrated communication system. In recent years, a wave of “building networks into space” has also swept across the ocean in the United States.
  SpaceX’s Starlink plan announced in 2015 will end its Beta test that started at the end of last year in October this year and enter the formal operation stage. Its average download speed in the US market can reach 97.23 Mbps, which is comparable to the speed of fixed fiber broadband. So, will the satellite Internet, which looks so “beautiful”, become the mainstream in the future?
  We can actually get a glimpse of it from the Iridium low-orbit constellation communication system built by Motorola in the 1990s.
Low-orbit satellite communications boom

  The Iridium project is a product of the early idea of ​​”3 geostationary satellites covering the world”. It was named after the iridium atom, trying to build a high-speed communication network of 77 (later reduced to 66) low-Earth orbit satellites like the 77 electrons surrounding the iridium atom.

Meteorological satellites above the earth

  Unlike high-orbit satellites in synchronous orbits, low-orbit satellites have a small coverage area and require multiple satellites to form an inter-satellite communication network such as a “constellation” to achieve global coverage. But also because it is closer to the earth, the signal transmission delay is greatly reduced, and the user experience is greatly improved.
  Iridium is planned to be officially put into use on November 1, 1998. U.S. Vice President Gore deliberately joined in and made the first Iridium call in the Rose Garden of the White House. After that, a series of satellite communications projects including Qualcomm’s GlobalStar and Orbcomm’s Orbcomm have attracted tens of billions of dollars of investment worldwide, triggering a wave of satellite communications at the end of the century.

  The intensive launch plan of the Tiangong space station is inseparable from a complete “low-latency” air-space-ground integrated communication system.

  But Destiny and Motorola made a huge joke. In the 1990s, it was not only satellite communication technology that was booming. The well-known second-generation mobile communication technology GSM network and GPRS mobile Internet are also being built in full swing around the world. Supplemented by submarine optical cables and tower-type mobile base stations, people gradually realized that the realization of global mobile communications may not need tall “satellites”, but only one by one seemingly inconspicuous ground base stations.
  In the late 1980s proposed by the Iridium satellite plan, mobile communications mainly relied on the “Big Brother” that was also developed by Motorola and adopted the first generation of analog signals. Motorola did not expect that the development of mobile communication technology would be so rapid, and it would run counter to its idea of ​​”going to the sky”. 15 months after the official launch of the Iridium plan, the user scale was only 1/10 of the expected, and the revenue could not even repay the interest of the loan, and it failed.
  Iridium filed for bankruptcy protection, Motorola also fell into a huge crisis. The 66 expensive satellites surrounding the earth cannot escape the fate of falling into the atmosphere and burning. Interestingly, the plan was finally acquired by the US Department of Defense, and it has been used in ocean freighters, mountaineering expeditions and other scenes and military applications. From this point of view, satellite communication based on low-Earth orbit is still useful, but it is completely different from Motorola’s original idea.
Going to space is more “close to the people”

  With Motorola’s lessons learned, why did SpaceX restart its low-orbit communications satellite program more than ten years later? This is actually related to the ultra-low satellite launch cost brought by SpaceX’s “Falcon 9” recoverable rocket.
  Before the “Falcon 9”, rockets costing tens of millions to hundreds of millions of dollars were not recoverable. Only the space shuttle can be reused. However, the high maintenance cost of the space shuttle makes the cost of each launch even higher than that of the rocket, reaching 400 million to 1.5 billion US dollars. At the same time, the structure is complex and the failure rate remains high, so that in recent years, American astronauts want to go international The space station has to rely on the Russian “Soyuz” rocket.
  SpaceX’s “Falcon 9” recoverable rocket was launched for the first time in 2010 and completed its first successful recovery in December 2015. The Starlink plan was also proposed in 2015 to build a huge satellite communication network composed of 42,000 communication satellites.

  U.S. Vice President Gore deliberately joined in and made the first Iridium call in the Rose Garden of the White House.

  On September 15 this year, “Falcon 9” also used the manned “Dragon” spacecraft to send four ordinary civilians who were not professional astronauts into space, completing a three-day journey. “Falcon 9” can deliver 15 tons of payload to low-Earth orbit at a price of 30 million U.S. dollars or less; the space mission, which originally cost hundreds of millions of dollars, has instantly become “friendly to the people”.
  At the same time, SpaceX borrowed from the automated production line of the Tesla Super Factory and upgraded the satellite manufacturing cycle that used to be a month as a unit to 2 per day. Basically, it can launch 50-60 satellites per month. This is in the past. It is unthinkable. In addition, the design ideas of satellites are completely different from traditional communication satellites. Most of the components are self-designed, with higher integration and far better performance than similar products.
  SpaceX’s low cost and high launch efficiency have overwhelmed OneWeb, one of Starlink’s biggest competitors. The latter filed for bankruptcy protection in March 2020 and was subsequently acquired by the British government and Indian telecommunications giant Bharti.
Accelerate spectrum seizure

  The Starlink project is highly praised in the United States, which is related to the sparsely populated area in the Midwest of the United States.
  The coverage radius of 2G base stations is 5-10 kilometers, while that of 5G base stations is only 100-300 meters. At the same time, the cost and power are very high. The inherent characteristics of cellular mobile networks have made the construction of high-speed mobile networks in a sparsely populated area a loss-making business. The demand for high-speed networks of the people in this part of the region is obviously more appropriate to achieve through satellite Internet.

On September 15, 2021, SpaceX sent 4 civilians into space orbit

  ”Starlink” signal receiving equipment can even be installed on the roof of the car in the future to realize “vehicle-based WiFi”. The signal will follow wherever the car drives. These advantages of satellite Internet perfectly hit the pain points of network construction in low-population countries such as the United States and Canada.
  In addition, SpaceX is building the Starlink network at such a fast speed, but also intends to seize the extremely limited spectrum resources: due to the propagation characteristics of radio waves, the number of signals that can be accommodated at the same frequency is limited. And because low-frequency radio waves cannot carry a lot of information, and the attenuation of high-frequency radio waves in the air is too large, under the existing technical conditions, the frequency band suitable for communication is basically in the range of 100Mhz-70Ghz.
  The ITU’s standard for the use of spectrum for satellite communications established in 2003 is “first come, first served.” If it continues to be used according to this standard, the current spectrum resources of communication satellites will be wiped out within a few years. In response to this situation, the ITU Communications Conference in 2019 updated the “Guidelines for the Application and Use of Spectrum for Non-GSO satellite constellations.”
  However, the new standards are not as strict as everyone thought, which still leaves a lot of room for operations for various countries and enterprises. The “Starlink” plan that Musk has been pushing hard has clearly taken the lead in this space spectrum war, laying a solid foundation for his future plans to land on the moon and even migrate to Mars.
  China also included satellite Internet in the list of new infrastructure constructions last year. Many aerospace companies, led by state-owned enterprises such as Aerospace Science and Technology Group and Aerospace Science and Industry Corporation, are also stepping up their plans for the Chinese version of the “Starlink” plan. In the near future, we may also be able to use network signals from space at home.

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