In June 2020, I went out in the middle of the night to spot a train of Starlink satellites in the sky. They are designed to provide Internet access anywhere on Earth. And that led to the question: how does satellite internet work and why isn't it more common? Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get an Original Essay Let's start with the basics of satellite internet. Traditionally, your home is connected to your Internet service provider via a phone line, coaxial cable, or fiber connection. Your ISP, in turn, is then connected to the wider Internet, allowing you to watch that video. Now, for satellite internet, the cable at your end is replaced with a wireless connection to a satellite orbiting the Earth. But this satellite is not connected to the Internet, so it sends the signal back to a ground station that is. This brings us to the most obvious drawback of satellite internet: delay, or latency. Most communications satellites are in geostationary orbit at an altitude of over 35,000 km and this considerable distance delays the search for an Internet query by 400 to 600 ms (round trip). The signal must travel from you, to the satellite, to the ground station, and then back to you. You would think that this wouldn't be much of a problem because these signals travel at the speed of light. But if you divide the distance between you and the satellite by the speed of light, you get 116 milliseconds. And this distance must be covered at least 4 times. But overall, satellite internet is fine for browsing the web, but anything that requires real-time interaction, like gaming or video conferencing, will be a pain. In terms of speed, it depends on where you are. Viasat, for example, promises 12 Mbps in most areas, with some going as high as 100. Not too bad, except they limit your monthly usage to between 12 and 150 GB, depending on your plan. And that means you can exceed the limits of the cheapest plan by downloading at maximum speed for just 2 hours and 13 minutes. Okay, so how does SpaceX plan to resolve these issues with Starlink? Well, for starters, they want to launch 12,000 satellites into low Earth orbit, at an altitude of about 550 km. This is 60 times closer than traditional communications satellites and reduces latency to just 25-35ms. Not as fast as fiber connections, but comparable to our current cable and cellular networks. A side effect of this proximity is that the satellites do not stay in the same place. They're constantly circling the Earth, which has implications for the antenna you'll need to use Starlink. But we'll talk about that later. As for speed, we don't really know yet what SpaceX will offer. But the US Air Force research laboratory has already tested Starlink on board an aircraft and achieved 610 Mbps. Not bad for a flight test! And in fact, it's 6 times faster than my current connection at home. To put that into perspective, that kind of speed would let you download a modern game of, say, 50GB in just over 11 minutes. My current connection, which is not far behind, needs an extra hour! SpaceX's COO said you'd be much happier with Starlink than with your current service because she promised more bandwidth for the same price or lower prices for the same amount of bandwidth. Let's move on to the hardware. The launch of 12,000satellites seems to be a big challenge, and to cope with it, Starlink satellites are small, light and cheap. They weigh just 260 kg (560 lb) and are launched in batches of 60 on top of a repurposed Falcon 9 rocket. Do they really need that many satellites? Well, SpaceX only needs 24 launches to have global coverage, so that's 1,440 satellites. Each additional satellite improves coverage and increases capacity. They have already completed 10 launches, so they are progressing well. But by far the coolest hardware on the Starlink satellites are lasers. As noted earlier, satellites are connected to the Internet via ground stations. But they are also connected to each other by lasers, forming a giant mesh network. And this comes in handy for long distance communications. With Starlink, your request can be transmitted to the nearest satellite, which can use its lasers to transmit it to other satellites closer to a ground station near California. An interesting tip to reduce latency, but also increases resilience. If a satellite cannot reach a ground station because it is offline, it can simply relay traffic to more distant satellites that can access a ground station. But why would you need to boost your satellite? Or why, deorbit? Well, this is done to avoid creating more space debris, also known as space junk. NASA is currently tracking more than 500,000 pieces of debris orbiting Earth. They vary in size, from small pieces of paint to dead, controllable satellites. But the problem is that they move at speeds of up to 28,000 km/h (17,500 mph), almost 10 times faster than a bullet. At these speeds, even tiny pieces of paint can cause serious damage to other satellites in orbit. A damaged satellite can then break up, producing more debris and causing more collisions. This endless cascade is known as Kessler syndrome, and if it occurs, it will make space activities very difficult, if not impossible, and will seriously affect us. Gone are satellites for GPS, weather forecasts, TV broadcasts and more the International Space Station. SpaceX is doing a lot of work to prevent this. The reason Starlink satellites are so close to Earth is not only to reduce latency, but also because at these altitudes the satellites experience atmospheric drag. If they do not strengthen periodically, they will burn up in the atmosphere after a few years. Clean up after themselves. This way, SpaceX doesn't have to worry about an unresponsive satellite. Who is Starlink for anyway? I mean, most people in Western countries have decent internet connections, right? Well, I was shocked to find an FCC report that said 21 million Americans, or 6% of the population, don't have a high-speed Internet connection. Another study puts this figure at 42 million. And Microsoft has suggested that 157 million Americans don't have Internet access described as "broadband." And this in a country that we consider “well developed”. If we zoom out and look at the rest of the world, things get even worse. UNESCO estimates that only 55% of households have an Internet connection. This is due to poor coverage or expensive service. In sub-Saharan Africa, for example, a single GB of data costs almost 40% of the average monthly salary. So this is what Starlink is intended for. Clearly, there is a market for high-speed, low-cost Internet access everywhere.