I was outside at night in June 2020 to see a Starlink satellite train in the sky. The satellites will provide Internet access to anywhere on Earth. Then I wondered: how do satellite Internet systems work, and why aren’t they more commonplace?
Let’s get started with some of the basic facts about satellite Internet. Your home has traditionally been connected to your Internet provider through a telephone line, coaxial cables, or fiber connections. The video you are watching is possible thanks to your ISP. With satellite internet, your cable is replaced with a wireless link to a satellite that orbits Earth. The satellite itself is not connected with the Internet. It beams its signal to a ground-station that is. Satellite Internet’s biggest drawback is its latency. This huge distance, which is over 35,000km high in geostationary satellite orbits, delays the search for Internet by 400 to 800ms. Signals must travel from the user to the satellite and back again. This would seem to be no problem since the signals are traveling at the speed light. The distance between the satellite and yourself is 116 milliseconds. This distance must be traveled four times. However, satellite Internet works well for web browsing but is not suitable for anything that needs real-time interaction, such as video conferencing and gaming.
It all depends where you are. Viasat, as an example, promises 12mbps for most areas and 100mbps for some. It’s not bad at all, but they only allow you to use between 12 and150GB per month, depending on the plan. You can download at maximum speed for only 2 hours, 13 minutes and still blow past the limit on the cheapest plan. So how will SpaceX address these issues?
For starters, the plan is to launch 12 000 satellites at a height of 550 km into low-earth space. It is 60 times more efficient than using traditional satellites for communication and the latency can be reduced from 100ms to just 25ms. It’s not as fast a fiber connection, but it is comparable with our current cable or cellular networks. Satellites move around because of the proximity. They continually circle the Earth. This has implications on your antenna for Starlink. Later, we’ll talk more about that.
SpaceX’s speed is still a mystery. Starlink was tested aboard an airplane by the US Air Force Research Laboratory, which achieved 610mbps. This is a pretty good result for a flight test! In fact, it’s 6 times faster that my home connection. In order to put it into perspective, a 50GB modern game could be downloaded in just 11 minutes. It takes an hour to upgrade my current internet connection. SpaceX’s COO claimed that you will be more satisfied with Starlink as compared to the service you currently have, because it promises greater bandwidth at the exact same price.
Now let’s talk about the hardware. Starlink Satellites are designed to meet the challenge of launching 12,000 satellites. They’re small, lightweight, and affordable. They are launched in 60-piece batches on a Falcon 9 rocket that has been repurposed. Does SpaceX really need so many satellites, or is it just a matter of convenience? SpaceX needs only 24 launches for global coverage. So, that’s a total of 1440 satellites. Every satellite that is added increases the capacity and improves coverage. The fact that they have already launched 10 satellites shows their progress. The Starlink lasers are probably the coolest part of the satellites. As we have already mentioned, satellites are linked to the Internet by ground stations. Lasers connect them to one another, forming an enormous mesh network. It’s also useful for long distance communications.
Starlink beams up your request so that it can be forwarded to other satellites near California using lasers. It’s a great trick for reducing latency. But it also improves resilience. If a space station is not accessible, a satellite that is further away can be used to relay traffic. Why would your satellite need to be boosted? Why de-orbit your satellite? Well, it is to stop the creation of space debris. NASA tracks more than 500,000 pieces debris orbiting the Earth. These debris are of all sizes, from tiny paint chips to controllable and dead satellites. It’s just that they can travel faster, up to speeds of 28,000km/h (17,500mph), or almost 10 times as fast as a bullet. Even tiny paint chips can cause serious damage to satellites orbiting in space. The debris from a damaged satellite can also cause collisions. Kessler Syndrome is the name of this cascade that can make space activities difficult or impossible. This means no GPS satellites or weather prediction, TV broadcasts or International Space Station. SpaceX has been working hard to stop this. Starlink satellites’ proximity to Earth isn’t just to reduce the latency. They are also at this altitude because of atmospheric drag. They will eventually burn up if they do not periodically boost themselves. After themselves. SpaceX will not be concerned about a non-responsive satellite.
Starlink is a service that was created for who? You know, I’m sure that most westerners have decent Internet connection, right? A FCC report stated that 21,000,000 Americans, or 6% of population, do not have a broadband connection. One study estimated 42 million. Microsoft reported that 157,000,000 Americans do not have internet that is considered ‘broadband’. UNESCO reports that only 55% households have access to the internet. It’s either because of poor coverage or an expensive service. In sub-Saharan Africa a GB of data can cost as much as 40% of a monthly salary. Starlink was designed for them. Evidently, there’s a demand for affordable, high-speed Internet access everywhere on Earth. The market for satellite internet could be huge. Morgan Stanley estimated the satellite internet market would reach over $400 billion by 2040.
What are the requirements for future Starlink subscribers? According to leaks, a small satellite dish will be required outside your home. The design is very similar to that of a satellite dish, but it’s much more elegant. It’s dead easy to use: just plug it in and point at the sky. It is quite different than TV dishes, for instance, which are aimed at certain places in the air. Because TV broadcasting satellites have a geostationary elliptical orbit that follows the Earth’s rotating and is always at the exact same place in space. Starlink satellites, however, are not. They are constantly moving. Starlink terminals have two features which can help fix the problem. The first is that it comes with motors which can be used to automatically adjust dish angle. Once in this position, the phased antenna electronically steers the signal to a Starlink Satellite. This can be done without moving the device physically and it can change satellites as they pass you by.
The last part of the essay asks: Has this been done before? The main reason is that it’s extremely expensive to launch satellites into space and design them. A launch using the Atlas Vrockets or Ariane 5 costs more than $165 million. SpaceX Falcon 9 only costs $62,000,000 or less than $300,000 if it has been flown previously. SpaceX has a huge advantage. They make money each time they launch the Falcon 9 for their customers AND they keep all of the rockets that land. So, each SpaceX customers brings more money into Starlink. Amazon and OneWeb are also taking a chance on this. Amazon’s Project Kuiper also includes 3,000 low-Earth-orbit satellites. As of yet, no satellites have been launched and it is not known who will be launching them. OneWeb plans on launching 650 Satellites but has only launched 34. The company was facing financial problems in 2020 and the UK government took a 45% share. SpaceX, however, is the only company that has its own satellites. Amazon may follow once Blue Origin starts up. I can’t help but be excited to see the impact that Starlink will have on the market and what SpaceX has planned for it.
