Why SpaceX needs 42,000 satellites? Explanation of StarLink
If you’re reading this blog, that means you have an internet connection, although you may live in an area with limited providers or network speeds. Still having internet accessibility can improve everything from entertainment, to work, to education, and health care. But 41.3% of the world doesn’t have access to the internet… at all. And that’s where SpaceX comes in with Starlink, which is getting very close to launching its service.
What is it, what are the latest developments,
and why should you care? So as I mentioned, internet access isn’t ubiquitous.
Just over 40% of the world doesn’t have any access to the internet yet, and
even in areas with access, it can be spotty if you’re not in more urban areas.
Places like Africa, the Middle East, and Asia are lagging behind areas like
North America and Europe. Laying long cable runs into remote regions can be
costly given the number of potential customers. Even building out wireless
signals in those areas is costly, which is why there are still many low bandwidth
areas or places with no signal at all in the United States. While 96% of urban
areas have broadband and access, only about 61% of rural areas do.
Satellite internet
service solves some of that problem because you can cover large areas with a
single satellite, but there are some big downsides. Current satellite-based
internet services are using geostationary satellites that are orbiting over
35,000 km (22,000 mi) above the surface of the earth. It’s that distance that
creates the first major problem: latency. A radio signal takes about 120 ms to
reach a geostationary satellite, with another 120 ms to relay that signal back
down to the ground.
So in theory you’d be
looking at at least 240 ms, but in practice, you often see a round-trip latency
between 400 - 600 ms. 12 times slower than what you see on the ground. And then
you have the challenge of how much bandwidth a single satellite can handle at
once, which can affect the download and upload speeds for everyone sharing that
satellite. That means your maximum upload and download speeds will most likely
be on the lower side, and you’ll have some data caps to contend with each
month. Viasat and HughesNet are two of the options you have today and cost
between $30-$150/month for speeds between 12-100 Mbps. And Viasat’s current
throughput in their satellites is about 260Gbps, which is shared by everyone
using it.
What this means is that
there’s an opening for competition, and that’s where SpaceX comes in with
Starlink. Since we already have satellite internet, what makes Starlink
different? It’s a low earth orbit (LOE) constellation of satellites that
operate around 1/3 to over 1/100 the height of geostationary satellites. As of
April 22, 2020, there are 422 satellites in the Starlink constellation so far,
with most of them deployed at around 550 km (340 mi) above the surface. They’re
trying to launch 60 satellites per Falcon 9 flight for a total of around 4,400
satellites in phase
1. And they’ll add
another 7,500 in phase
2. So around the year
2027 they’ll have nearly 12,000 satellites deployed in three orbital shells.
Now it’s not guaranteed, but SpaceX has also submitted paperwork for an
additional 30,000 satellites beyond that. Why so many satellites? Low earth
orbit satellites, being much closer to the earth, means they can’t be
stationary. They have to move faster to maintain their orbit, and they also
have a smaller cone of coverage. But a big benefit of being so much closer is
much lower latency for communication. It will have latencies around 25-35ms, which
makes it comparable to cable and fiber-optic networks. However, when using
lasers to communicate between satellites, which Starlink will eventually do, it
gets a little physics boost. Light travels through a vacuum about 47% faster
than through glass, like a fiber optic cable. So even when accounting for
transmitting from the planet and back, the faster laser transmission speeds
between satellites will give the network a latency edge compared to long
stretches of fiber on earth. And each satellite will be able to handle 1 Tbps,
which is almost 4 times the capacity of Viasat. That’s roughly 40,000 people
streaming 4K video at once.
While all of that
sounds incredible, this isn’t a service that’s meant to knock out terrestrial
internet service. It’s a service meant for a smaller segment of the market,
which is primarily areas less densely populated. Just this past March, Elon
talked about that at the Satellite 2020 conference. ”And the challenge for
anything that is space-based is that the size of the cell is gigantic. It’s
great for very low to maybe medium sparsity situations, but it’s not good for
high-density situations. We’ll have a small number of customers in L.A but we
can’t do a lot of customers in L.A. because the bandwidth per cell is simply
not high enough.” -Elon Musk
With tens of thousands
of satellites being put into orbit, it’s going to dwarf everything that’s come
before. At this point in our history, we’ve only launched about 9,000 objects
into space. And of those, a little less than 6,000 are still in use today.
SpaceX is going triple that number in 5 to 7 years. And if they move forward
with the additional 30,000, you can probably understand why a lot of people are
concerned about overcrowding and space debris. If you’ve ever seen the movie Gravity,
then you probably know about Kessler syndrome. It’s the theory that an object
colliding with another in a densely packed area of space could cause a cascade
of destruction.
The FCC required very
strict plans from SpaceX to mitigate space debris, which meant achieving
a higher level of
de-orbiting reliability than NASA uses for itself: 90% of satellites reliably
de-orbiting. With a targeted lifespan of 5-7 years, SpaceX told the FCC that it
will "implement an operations plan for the orderly de-orbit of satellites
nearing the end of their useful lives at a rate far faster than is required
under international standards." And that SpaceX satellites "will
de-orbit by propulsively moving to a disposal orbit from which they will
reenter the Earth's atmosphere within approximately one year after completion
of their mission." About 95 percent of the satellites’ parts will
disintegrate in the Earth’s atmosphere as they de-orbit.
There have also been
concerns about the impact on astronomical observations. With the satellites
being very visible when deployed, and also noticeable as they’re reaching their
final orbit, astronomers are worried about light pollution. SpaceX has been
working with astronomers to address these concerns with strategies like
painting sections of the newer satellites black to reduce reflection. Or
adjusting their orbit orientation to minimize how the satellite will catch and
reflect sunlight towards the surface during their orbit. And even adding a
sunshade to the satellite to help block reflections. They’re calling it
VisorSat. There’s still a lot of outstanding questions around how this will
ultimately impact visual and radio telescope observations, but SpaceX is
actively trying to address them. SpaceX isn’t the only company working on low earth
orbit constellations for internet service. Companies like Telesat, OneWeb, and
Amazon all have plans, but nobody has successfully launched a business out of
this. Amazon is working on Project Kuiper, which will have around 3,200
satellites, but has yet to put any satellites into orbit. And OneWeb, which
launched 74 satellites, just filed for bankruptcy in March of 2020.
”Guess how many LEO
constellations didn’t go bankrupt. Zero. Zero. Iridium is doing okay now, but
Iridium 1 went bankrupt. Worldcom went bankrupt. Globalstar, bankrupt.
Teledesic, bankrupt. Am I leaving anyone out? There’s a bunch of others that
didn’t get very far ... and they all went bankrupt. Anyway, they all went
bankrupt.” -Elon Musk
“So you’re focusing on
making it work first?” -Jeffrey Hill
“Not bankrupt.” -Elon
MuskThere’s a big business opportunity for the company that can get up and
running first, which is looking like SpaceX. In 2018 they estimated the total
cost to be about $10B, which is a lofty price tag for a company that’s expected
to make around $3B - $5B a year from launches by 2025. The projections for
yearly revenue from Starlink are $30-$50B a year by 2025. But that’s a means to
an end for Elon and SpaceX. In a media call before the launch of the first
Starlink satellites, Elon said: ”We see this as a way for SpaceX to generate
revenue that can be used to develop more and more advanced rockets and
spaceships. We believe we can use the revenue from Starlink to fund Starship.”
-Elon Musk Which leads right to the goal of becoming a multi-planetary species.
”There are two fundamental paths history is going to bifurcate along with two
directions.
One path is we stay on
earth forever, and then there will be an eventual extinction event. I don’t
have an immediate doomsday prophecy, but eventually, history suggests that
there will be a doomsday event. The alternative is to become a space-faring
civilization and a multi-lantern species, which I hope you agree is the right
way to go. Yes? That’s what we want. (Points at Mars)” Elon Musk Back to earth,
we’re not going to have to wait too much longer before seeing Starlink in
action. But before I get to when Starlink is going to be available, it’s a good
time to talk about getting a VPN for your internet … whether it’s terrestrial or
space-based.
The private beta
service is scheduled to start in the northern US and Canada around August 2020, with a public beta following that up in
November 2020. Part of the reason for the limited scope is due to where the current
satellites are orbiting. As more satellites join the constellation, we’ll see
more areas rolled into the beta program. It’s going to be interesting to see
how well the system performs over the next year or two, and what opportunities
it opens up for mobility, internet access, and other businesses. Areas that
have no or poor internet availability will benefit the most from Starlink, but
so will areas with a lack of competition. And if it proves to be as low latency
as promised, it could be a huge moneymaker for high-frequency stock traders.
It’s not just gamers that benefit from low latency. Starlink’s projected 25-35
ms latency is faster than anything stock traders have today between major
trading centers in the US and Europe. In businesses where every millisecond
counts, Starlink could mean big business.
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