Everything Everywhere Daily: History, Science, Geography & More - Communication Satellites

Episode Date: July 25, 2022

Once humans managed to put artificial satellites into orbit, the next question was, “what can we do with this?” One of the first applications of satellites, and still one of the biggest uses still today, has been for communications.  Using satellites for communications requires cutting-edge technologies in space flight, solar power, radio engineering, and computers.  Learn more about satellite communications, its history, and how it works, on this episode of Everything Everywhere Daily. Subscribe to the podcast!  https://link.chtbl.com/EverythingEverywhere?sid=ShowNotes -------------------------------- Executive Producer: Darcy Adams Associate Producers: Peter Bennett & Thor Thomsen   Become a supporter on Patreon: https://www.patreon.com/everythingeverywhere Update your podcast app at newpodcastapps.com Search Past Episodes at fathom.fm Discord Server: https://discord.gg/UkRUJFh Instagram: https://www.instagram.com/everythingeverywhere/ Twitter: https://twitter.com/everywheretrip Website: https://everything-everywhere.com/everything-everywhere-daily-podcast/ Everything Everywhere is an Airwave Media podcast." or "Everything Everywhere is part of the Airwave Media podcast network Please contact [e-mail] to advertise on Everything Everywhere. Learn more about your ad choices. Visit megaphone.fm/adchoices

Once humans managed to put artificial satellites into orbit, the next natural question was, what can we do with this? One of the first applications of satellites, and still one of the biggest uses today, has been for communications. Using satellites for communications requires cutting its technologies in spaceflight, solar power, radio engineering, and computers. Learn more about satellite communications, its history, and how it works on this episode of Everything Everywhere Daily.

What if your perceptions about the past were wrong? ThruLine is a podcast that takes you back in time to uncover the parts of the story that may have gone unnoticed. It effectively turned day into night. And how it shaped the world now. Time travel with us every week on the ThruLine podcast from NPR. The origin of satellite communications actually goes back to before the first satellite was put into orbit. British science fiction author Arthur C. Clark had been a proponent to the idea of space travel since the 1930s. In 1945, he wrote an article for Wireless World magazine titled,

Extraterrestrial Relays, Can Rocket Stations Give Worldwide Radio Coverage? In this article, he proposed the idea that if a satellite were to be put into the correct orbit, the time it would take to orbit the Earth would be precisely the same as the amount of time it took the Earth to rotate on its axis. The end result would be a satellite that would stay in one spot above the Earth, just as if it were hung from the ceiling. It's known as geosynchronous orbit. The location of this orbit lies 35,786 kilometers, or 22,236 miles above the equator. A satellite in such a spot could receive a radio signal from anywhere on Earth that it could see

and send a radio signal to anywhere on Earth that it could see. It was this potential for satellite communications that was one of the biggest driving forces behind the very early space race. The first thing that could even be called a communication satellite was the SCORE satellite, launched in December 1958, and SCORE stood for Signal Communications by Orbiting Relay Equipment. All it really was was a tape recorder that could receive record and transmit voice messages. It was by far the largest object ever put into orbit at this time, as it was 80 feet or 24

meters long. But it was only in orbit for a month. In 1960, NASA launched the first passive communication satellite known as Echo One. Echo One was nothing more than a giant metallic balloon that orbited the Earth. radio signals would be sent to the satellite, which would then just be reflected back down. It was incredibly simple, but not very sophisticated, and it didn't work very well. The satellite, which is usually considered to be the first true communication satellite, was Telstar, which was launched in 1962. Telstar was created by Bell Labs, which, if you remember back to my previous episode on it, invented everything.

Several things made Telstar different from previous satellites. For starters, it was solar-powered with the ability to produce 14. watts of power. And second, it contained a new electronic device called a transponder. A transponder is a device that will receive a radio signal and then rebroadcast a signal after amplification. And it's become a critical component of all communication satellites ever since. Unlike Echo 1, Telstar was an active system, not a passive system. Telstar set a host of first for communications satellites, including the first live transatlantic television broadcast, the first satellite telephone call, the first satellite

telefax image, and the first computer data sent by a satellite. Researchers were able to synchronize the clocks between the United States and the United Kingdom down to within one microsecond, which was 2,000 times better than it was before. Telstar, however, was not

in geostationary orbit. That meant that the parties on either side of the Atlantic could only use the satellite for about 30 minutes of each two and a half hour orbit. Telstar functioned for about four months before it went out service, and it's actually still up in orbit today non-functioning. Despite its short life, it was considered a huge hit, having conducted hundreds of broadcasts. The next big innovation

was the launch of the first satellite to be parked in geosynchronous orbit. And here I should briefly explain the difference between geosynchronous orbit and geostationary orbit. A geosynchronous orbit is any orbit that has the same orbital period as the rotation of the Earth. And I should note that a day in this context is a sidereal day, not a solar day, and that would mean an orbit of 23 hours, 56 minutes, and 4 seconds. A satellite, however, can have an orbital period of one day, but not be a single spot in the sky. Its orbit could be slightly inclined and have an eccentricity, in which case it will appear to do a figure 8 in the sky. It would be roughly in the same spot, but not exactly in the same spot. A geostationary orbit is a geosynchronous orbit with almost no

inclination or eccentricity. It orbits on a plane parallel with the Earth's equator. The first satellite to be put into geosynchronous orbit was Syncom 2 launched in 1963. Like Telstar, Syncom 2 had several firsts, including the first satellite call between heads of state, when President John Kennedy called the Nigerian Prime Minister Abukar Tafawa Beliwa. In 1964, Syncom 3 became the first satellite to be put into geostationary orbit. While these satellites were a success, the real question was how satellite communications were going to be used for commercial purposes. The United States addressed this by passing the Communications Satellite Act of 1962. This allowed for government regulation of satellite communications and also allowed for every communications company licensed by the FCC to use satellites.

This led directly to the creation of the Communications Satellite Corporation, or ComSAT. ComSAT was a public-private partnership to use communication satellites. Another organization, known as the International Telecommunications Satellite Organization, or IntelSat, was an intergovernmental consortium that managed communication satellites. The reason for these organizations was that geostationary communication satellites were really expensive, far beyond the reach of something like a television network. For the most part, companies didn't need a full-time satellite at this point. A TV network might file a story from another country, and they would just need to book a time to send the video back to their headquarters.

The first commercial communication satellite was Intel Sat 1, which was launched in 1965. The Soviets, despite all of their early accomplishments in space, were behind the Americans when it came to satellite communications. They neither had the money, technology, nor the market to support large-scale communication satellites. They launched their first communication satellite in 1965 as part of the Molnia program, These Soviet satellites were very unlike their American communication satellites in one major respect. The Soviet satellites were designed for domestic use, in particular for communications in the polar regions. The thing is, geostationary satellites don't work very well if you happen to live in extreme in northern or southern latitudes. I remember visiting Iceland once and noticed how all the TV dishes were pointed not up in the air, but almost at the horizon.

The Soviets used what's now known as the Molnia orbit. It's a highly elliptical orbit that spends most of its time over the poles. Unlike a geostationary orbit, the satellite is constantly moving in the sky, and it isn't available all of the time. However, if you happen to live in the Arctic, it's a lot better than nothing. Satellite communications grew over the next few decades. Improvements in electronics and solar panels made for much better satellites and improved launch capabilities allowed for bigger satellites. When something was live via satellite, it was usually a major event, like the Olympics or something. One of the first and biggest satellite events took place on January 14, 1973, when Elvis Presley performed a concert called Aloha from Hawaii via satellite.

It was broadcast live in Australia and Asia. Starting in the mid-1970s, entire satellite-based television network started to spring up. These networks would use KU band satellite channels to send their network signal to cable TV operators, who would then play the network feed locally. If you happen to own a large KU-Ban satellite dish, you could actually pick up these stations directly as they had an analog signal. These systems, however, were large and expensive. They were eventually replaced by smaller digital dishes which could be sold directly to consumers. Because their signal was digital, they could be encrypted, which means access could be controlled.

They also offered more channels and a higher quality signal. Television turned out to be the ideal use for satellites because it only requires a one-way signal. Millions of people could catch the signal sent by a single satellite because nothing was sent back up to orbit, and the same holds true for digital satellite radio which began in the early 2000s. It turns out that geostationary satellites are not very good at two-way communications. For starters, you need a channel for every user, which can really get expensive quickly. Furthermore, geostationary orbit is a long ways away. To put this into perspective, geostationary orbit is about 90 times.

further away from the Earth than the International Space Station. It's far enough away that the speed of light starts to become an issue. Round trip from the Earth to geosynchronous orbit and back takes about a quarter second for light. If you've ever been on a cruise ship or a remote island and have tried using satellite telephones or internet, you've experienced just how bad and expensive it really is. The solution to this has been known for a while, but it was very difficult to build. a network of low-Earth orbit satellites. This approach is totally different from a geostationary satellite. Instead of one satellite, very far away that doesn't move,

you have a whole bunch of satellites much closer to Earth that are constantly moving overhead. The first company to seriously propose a satellite network like this was Teledesic. They were founded in the 1990s by cell phone network pioneer Craig McCaw and Microsoft founder Bill Gates. They spent billions of dollars, but never asked, actually managed to put a satellite in orbit. Several companies have proposed similar systems, including Amazon and one web.

However, as of today, only one company has really been able to deploy a very serious low-earth orbit data network, SpaceX. Their Starlink network currently has over 2,700 satellites in an orbit of 550 kilometers. By keeping the satellites that low, the time for signals to travel from space to the ground is minimal. because there are so many, each satellite is able to provide more bandwidth to a smaller number of people that they happen to be passing over at the time. The Starlink system is like a reverse cellular network. In a normal cellular network, you move around a network of fixed antennas. With Starlink, the antennas are moving, and the receivers are relatively standing still. The reason why SpaceX is able to make it work where a company like Telodesic wasn't is primarily that they own their own launch vehicles.

They have decreased the cost of sending a kilogram to orbit by almost a factor of 10 by reusing their rockets. The satellites they use are small and mass produced, unlike traditional communication satellites, which are big and custom built. A typical launch will send 40 Starlink satellites into orbit at once. If and when the Starship system starts to launch, which I've done a previous episode on, that might increase to 400 satellites per launch. Current users are able to get speeds between 200 to 300 megabits per second, even in remote areas, with ping times under 30 milliseconds. Currently, the satellites just send signals back to a ground station within sight, but the next generation of satellites will be able to send data to each other via laser connections to route data in the vacuum of space. And in theory, this will be faster than a fiber optic cable for routing data around the world because light travels faster in a vacuum than it does in fiber.

As this is just a data connection, you can also use it for voice, video streaming, or anything else he would use an internet connection for. Future plans are for as many as 40,000 satellites, which would provide hide-speed connectivity everywhere from Antarctica to Andorra. Another difference between low-earth orbit systems and geostationary systems is the type of antenna you use. Geostationary satellites require a dish-shaped antenna that you've probably all seen. This is used to amplify the weaker signal to the receiver. A low-earth orbit system uses what's called a phased array antenna. It's usually just flat and points generally up, but it can electronically move where it's sending and receiving its signal from

as the satellites are moving overhead. A dish antenna is rather dumb, but a phased array antenna is actually an expensive piece of electronics. I will end by noting one other type of satellite communications that most people may have never heard of. Ham radio operators have dabbled in satellite communications for years. They've managed to get a few cheap micro satellites in orbit, which are used by hobbyists.

However, there is another technique that some ham radio operators use that involves a satellite. It's called EME Communications, which stands for Earth, Moon, Earth. It was first proposed and tested in the 1940s, and it does indeed work. You point a transmitting antenna at the moon, and then a very weak signal bounces back to Earth. You need an enormous antenna to receive it, but it can be done if you can tolerate a 2.5 second delay. I've been fascinated by satellite communications for years, and I continue to be. And we are now entering a new era where satellites will be able to bring fast, affordable connectivity to everyone on Earth, regardless of where they happen to live. Everything Everywhere Daily is an Airwave Media podcast.

The executive producer is Darcy Adams. The associate producers are Thorntomson and Peter Bennett. I just wanted to extend a big thank you to everyone who is supporting the show over at patreon.com. I have show merchandise available there, including hoodies, t-shirts, and stickers. Plus, it really just helps me get this show out every single day, including, of course, weekends and holidays. Remember, if you leave a review or send me a boostogram, you too can have it read on the show. From a ground station nestled in the mountains at Andover, Maine, a signal is sent to a speeding satellite, an historic feat that could reshape man's future.

That satellite, of course, is the Telstar, a hundred and seventy pounds of complex, electronic equipment that receives signals beamed from Earth, magnifies them 10 billion times, and rebroadcast them back to Earth. Pictures, telephone calls, telegraph messages, and computer data, all can be handled by the orbiting device. The Telstar

receives its power from batteries that are recharged by the sapphire-coated solar cells, which in turn are activated by rays from the sun, as it hurtles through space at a low point of 600 miles to a high of 3,500 miles.