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  • Elon Musk is at it again.

  • The billionaire behind companies like Tesla and SpaceX is known for his audacious plans,

  • and in October of 2019 he took them one step further,

  • when SpaceX sought permission to launch 30,000 satellites into orbit.

  • That's on top of the 12,000 satellites they've already been given approval for

  • as part of their Starlink megaconstellation that aims to beam high speed internet around the globe,

  • starting with service in North America as soon as 2020.

  • For the math inclined among you,

  • that means SpaceX would like permission to launch up to 42,000 satellites into low earth orbit.

  • And the only question I have is: Why?

  • If you were to head over to SpaceX's Starlink website,

  • you'd see that their main selling point is global connectivity:

  • something that would benefit people in rural areas or in places where current internet service

  • is too expensive or unreliable.

  • And that's all commendable, since it'd be great if everyone around the globe had access to the internet

  • and the fine educational content available on Seeker.com.

  • But 42,000 satellites is an extreme amount of high tech hunks of metal to launch into space.

  • For context, right now the UN Office of Outer Space Affairs

  • estimates there are about 4,000 satellites in Low Earth Orbit.

  • So SpaceX alone would like to launch up to 10 times that.

  • The idea is to form a web of satellites whose orbits criss-cross and provide global coverage.

  • It seems like a very expensive proposition, so is there more to this project

  • than just making the world wide web truly world wide?

  • SpaceX is a business, and they wouldn't do something like this if it couldn't turn a profit.

  • Despite the project's estimated minimum price tag of 10 billion dollars,

  • Musk believes it could bring in as much as 30 to 50 billion dollars in revenue each year.

  • Why is it worth so much?

  • It's all about cutting latency time,

  • or the amount of time it takes information from your computer to reach its destination and come back.

  • Here on Earth, the preferred way to transmit large amounts of information over long distances

  • is through fiber optic cables.

  • These bundles of glass fibers carry beams of light from one point to another,

  • taking advantage of light's extreme speed.

  • But because light has to travel through the medium of glass,

  • it doesn't reach the same top speed it does in a vacuum like in space.

  • In a vacuum, light travels at nearly 300 million meters per second,

  • but bouncing through glass that speed drops to around 204 million meters per second.

  • That adds a few microseconds of latency per kilometer.

  • So sending information through space could save a lot of time, provided it's done in the right way.

  • For decades we've used satellites to send data to remote parts of the world,

  • but typically the ones we use are in geosynchronous orbit,

  • where they appear fixed over one spot in the sky.

  • To achieve that positioning, the satellites have to be in very distant orbits over 35,800 km high.

  • That means that even using light at its max speed, latency times are around 700 milliseconds.

  • So SpaceX plans on putting its satellites much closer to home, operating at 550 kilometers up.

  • At this altitude it's impossible for them to stay over one spot

  • they have to move faster to stay in orbit. Hence the need for so many of them to maintain coverage.

  • But at that distance, a network of satellites passing along information at light's top speed

  • will have less latency than any fiber optic network longer than 3000 kilometers.

  • And the farther the data has to travel,

  • the more of an advantage a network like Starlink will have over its terrestrial fiber optic counterparts.

  • This high speed link is worth incredible amounts of money to financial markets,

  • where milliseconds of delays can translate to millions of dollars lost as markets shift.

  • Starlink still has a long way to go before its promise can be realized.

  • The satellites will have to be cheap and reliable enough to justify launching thousands,

  • and once they're up there, they need working autonomous collision avoidance

  • to keep from smashing into other satellites and causing a runaway debris problem.

  • Astronomers are also warning that so many satellites sending so many radio waves

  • could interfere with ground based optical and radio observations,

  • so SpaceX is working out how to build and operate their satellites in a way that doesn't affect them.

  • And of course SpaceX isn't the only company racing towards satellite broadband,

  • with companies like OneWeb and Amazon's Project Kuiper pursuing similar goals.

  • In fact, that may be why they applied to launch 30,000 more satellites: as a move to box out competition

  • rather than because that's the demand they anticipate.

  • All-in-all it's another classic Elon Musk project.

  • It aims high and promises huge returns, and it's not without its skeptics and dissenters.

  • Will a constellation of satellites connect the world while still keeping the skies clear for science

  • and other spacecraft?

  • We'll just have to wait and see.

  • Even if the speed information is sent around the world speeds up,

  • a slow wifi router can still bottleneck your system.

  • To learn how WiFi 6 will speed up your internet, check out my video on it here.

  • If you liked this episode, let us know in the comments below.

  • And make sure to subscribe to Seeker and thanks for watching.

Elon Musk is at it again.

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埃隆-馬斯克的Starlink將如何在全球範圍內提供互聯網? (How Will Elon Musk’s Starlink Deliver Internet Around the Globe?)

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    林宜悉 發佈於 2021 年 01 月 14 日
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