Camelot on the Lizard Penninsula

Goonhilly Satellite Earth Station is a large telecommunications site located on Goonhilly Downs. From that name you probably already guessed this is in the UK. Specifically it's in Cornwall on the oddly named Lizard peninsula. (Marconi built one of his earliest wireless stations there in 1900. It's still standing. [LINK] )
At one time Goonhilly was the largest satellite earth station in the world. It had over 60 communications dishes at the site. Currently that title is held by the Madley Communications Center in Herefordshire in the UK. The site also uniquely connects to undersea marine cables. That's the data gamut: underwater to outer space. More here.

The 140 acre site was built the the UK post office starting in 1961, and in 1962 it carried the first transatlantic television broadcast. They only yielded control of the site when the Tories privatized their postal service in 1984 and the site was given away to BT Group. I blame Margaret Thatcher. BT tried to close the site in 2006 to build a wind farm. The historical status of one 50 year old dish stopped them.

Goonhilly also has maintained an informal tradition of nick-naming it's satellite dishes. Its first dish was dubbed Arthur when it was built in 1962 to link with Telstar. It's largest dish has a diameter of 32 meters and is nick-named Merlin. Numerous characters from the legend of King Arthur and Camelot are represented at the site. The site's largest dish, dubbed "Merlin", has a diameter of 32 meters. Other dishes include Guinevere and Isolde after characters in Arthurian legend, much of which takes place in Cornwall. there's an incomplete list here.  One travel guide from the year 2000 claimed Goonhilly then had 25 dishes named after gods and characters from Cornish legends.

Depending on which stories you consider part of the Arthurian cannon, there are up to 152 names available for use at Goonhilly. There are sites available for development if you are interested. Some highlights below:

Arthur - 1962 - 26 meter dish (Goonhilly1)
Uther - 1968 - 27 meter dish (Goonhilly2)
Guinevere - 1972 - 29 meter dish (Goonhilly3)
Lancelot - 1978 - 19 meter dish (Goonhilly4)
Geraint - N/A - /unknown - (Goonhilly5)
Merlin - 1962 - 32 meter dish (Goonhilly6)
Tristan - 1983 - 13 meter dish (Goonhilly7)

Low Earth Orbit Broadband Satellite

Google has generated a bit of press in the last week with their Project Loon and their funding of O3b Networks.  I for one am optimistic, but equally amused with the apt naming of a looney project. But internet from space is radio, and radio is something I know about. The big question remains.. is there any efficacy in  a space-bound ISP that can provide global connectivity? In a word?  Maybe.

These low earth orbit broadband satellite ventures are promising nothing short of Satellite Internet access. But in a way, that has been the promise all along. The first commercial communications satellite was Telstar 1, built by Bell Labs and launched in July, 1962. The first satellite to successfully reach geostationary orbit was Syncom3 which was launched the following year. Telstar 1 had only one transponder to relay data. It operated in the C-band (4 to 8 GHz ) receiving 6 GHz microwave signals and responding on 4 GHz omnidirectionally. This was not going to move a lot of data. It did relay television signals, it's orbit only allowed it to do so in 18-minute segments as it whipped over continents 3,500 miles above the surface. Telsar 2 was identical, but the Syncom series that began launching in 1965 were at least geosynchronous.

But the real excitement came in the 1990s. In 1993 the Hughes Aircraft Co.asked the FCC for permission to launch a satellite that transmitted in the Ka-band (26.5–40 GHz.) This matters because there is a direct relationship between frequency and bit rate. Frequency is just the number waves per second measured in Hertz (Hz). So a 100MHz signal can transfer 100,000,000 wave cycles of current in one second, but that's only 0.1 GHz. Bit rate is the number of bits of data transferred in one second. We measure this in bits per second (bs.) If you imagine each wave as a bit you can see how increasing the frequency increases the bit rate. (Though clearly encoding schemes also increase speed.) Consequently moving from 6 GHz to 26 GHz was pretty significant for data transfer.

In 1995, the FCC opened up applications for other Ka-band satellites. Fifteen companies applied including: EchoStar, Lockheed Martin, GE-Americom, Motorola and KaStar Satellite.. one of the first that tried to offer ISP service was Teledesic. They launched in 1998 operating between 28.6 and 29.1 GHz. 9 billion dollars and 8 years later it went bankrupt. The project was totally abandoned by 2003. But that same year Eutelsat launched 31A which provided broadband services in Europe. First called e-bird and later Eurobird, it was renamed in 2012. it's still in service. Anik F2 went into service in 2004 delivering a similar service to Canada, but was capable of a very impressive 140 Gbit/s with 114 transponders.  Of these 50 operate in the Ka-band, 40 in the Ku-band (12–18 GHz), and 24 in the C-band. That was a decade ago. In more recent years, ViaSat-1 and HughesNet’s Jupiter have proven capable of data rates of up to 15Mbit/s. That's better than I get from my cable provider. (ahem) There are now a slew of these high throughput satellites.

• Anik F2 (2004) 
• Thaicom 4 (2005) 
• Spaceway-3 (2007) 
• WINDS (2008) 
• KA-SAT (2010) 
• Yahsat Y1A (2011) 
• ViaSat-1 (2011) 
• Yahsat Y1B (2012) 
• EchoStar XVII (2012) 
•  HYLAS 2 (2012) 
• Astra 2E (2013) 
• O3b Satellite Constellation (2013) 
• Inmarsat Global Xpress constellation (2013) 

So back to Google and O3b.  Those satellite broadband ventures of the 1990s and 2000s didn't fail. They've created a cache industry in rural and third world internet service. While Microsoft's funding of Teledesic may have gone nowhere, so did Windows ME, Vista and 8. Google has a better track record for holding and folding. They also clearly have the bank balance to launch and support more high throughput satellites. This isn't something new, this is more of something we have already proven can be done. I, for one, welcome our new Internet overlords.

Venus Equilateral

It's often the case that science fiction precedes science non-fiction.  Science fiction author Arthur C. Clarke envisioned satellite communications long before it was a reality.  In this case Clarke wrote a serious proposal called "Extra-Terrestrial Relays" for geostationary communications satellites in 1945. You can read that here. But he had been inspired by the Venus Equilateral series of short science fiction stories by George O. Smith. The first of these were published in 1942.  The Smith stories concern the Venus Equilateral Relay Station, an interplanetary communications hub. Smith had the idea 3 years before Clarke and 20 years before the Telstar 1 satellite was launched on July 10, 1962.

Prior to the use of communication satellites, we had only two systems to defeat the curve of the earth. We had terrestrial wired systems, and we had microwave relay systems with towers on hilltops about 30 miles apart. But these systems were not great. Spanning just the North American continent took 107 hops by microwave relay. Prior to 1954 transatlantic cables were mostly fiscal and/or technological failures. Until the 1950s transatlantic telephone service was primarily radio-based. Technology had to catch up to the idea, but in the years after Clarke's proposal, the world began considering another approach. (Which we ironically reversed over the last decade)

Sputnik I was launched by the USSR in October of 1957, and the USA launched Explorer I in 1958. These were satellites, but not communication satellites.  In December of 1958 we launched Score under the Defense Department's ARPA program (Advanced Research Projects Agency). It was a shiny metallic mylar balloon 100 feet in diameter. It was in the spirit of, if not the design of some passive reflector design proposals written by J.R. Pierce around 1954. The actual unit was designed by Kenneth Masterman-Smith.  It contained two tape recorders (for redundancy) and four antennas two for transmission and two for reception. The frequencies used were 150 MHz for the uplink and 132 MHz for the downlink. Its batteries lasted 12 days and it then burned up on re-entry in January of 1959. It broadcast the first human voice communication from space on December 19th. President Eisenhowers words were as follows:

"This is the President of the United States speaking. Through the marvels of scientific advance, my voice is coming to you via a satellite circling in outer space. My message is a simple one: Through this unique means I convey to you and all mankind, America's wish for peace on Earth and goodwill toward men everywhere."

That's what he said, but what he meant was the U.S. now had the ability to deliver a nuclear weapon from space. The Russians took this poorly. More here. AARPA moved on with a project called Advent and Echo to mixed success. Echo was another 100ft passive reflector mylar balloon this one launched in August of 1960. It remained in orbit until May of 1968. Echo II was a bit more interesting. It was bigger at 135 feet in diameter, and was launched January 25, 1964. It came down in 1969. Following Echo, passive communications satellites were abandoned. Telstar 1, the first production active communication satellite was launched on July 10, 1962.

SIGINT

SIGINT is a blend of two words Signal and Intelligence. In this use I refer to information gained from intercepted radio signals, including broad traffic analysis. Since first days that data could be transmitted, opposing parties were trying to intercept it. A detailed history of SIGINT would take many thousands of pages. Thankfully I'm only interested in it's radio applications. But before I try to find a narrative here, let me first roll out a bit of military jargon:

COMINT - (Communications Intelligence) communications between people.
ELINT - (Electronic intelligence) communications not containing speech or text.
OpELINT- Operational ELINT
MASINT - (Measurement and Signature Intelligence)
FISINT - (Foreign Instrumentation Signals Intelligence)
LEO COMINT  - Space based communications with orbiting satellites below 2000 km
GEO COMINT - Space based communications with geosynchronous satellites

These are all programs at US security agencies. SIGINT includes radio, but is not limited to radio. It's best summarized broadly as intelligence-gathering by the interception of signals. This even includes conversations  (COMINT.)  It also, traffic analysis—not just traffic but signal on the radio band as well. It's an examination of who sends signals to who, and how often. That's regardless of whether the signals themselves can be decrypted and/or understood. This is what spooks do. They are not James Bond, they are peeping toms. By and large most people are OK with that. More here.

Obviously these programs are much older than the agencies that oversee them now. Eavesdropping is surely as old as our species, Encryption is at least as old as the Romans, and probably cracked in the same era.  But ELINT is only as old as radio. Some of the first intercepted signals were transmitted in 1900 during the Boer war.  The British went on to monitor Russian marine wireless in the Russo-Japanese War in 1904.  This all became more of a international game in WWI. The British cut German undersea cables, forcing them to use radio so they could intercept the signals. The British built Y-stations on land and afloat  for interception and direction finding.

US was late to the game. Our communications monitoring of naval signals started around 1918. The Navy built 52 direction finding sites on the East Coast. What little we built in WWI was let to rot in the interval. We only ramped up again in the lead up to WWI in order to provide some direction finding on Japanese signals in the Pacific. Real COMINT programs started in the late 1930s with ships intercepting signals from Germany and Italy. When japan again joined the fray we ramped up on the west coast as well. Following WWII the military began approaching permanent monitoring installations, a direction remains unchanged today.

Radio Signals in Space

I've discussed at length the myth that radio signals always travel at the speed of light. Post here. But I thought it would be an interesting exercise to determine how long it would take radio signals to reach various points in our galaxy . If you get the urge to check my math be aware that many sources cite distances in AU, (Astronomical Unit) which is equal to 149,597,870,700 meters, or about 92,955,807 miles. The basis for that unit is the distance of the Earth from the Sun which is random and pretty useless. More here.

The length of time needed to send radio signals depends on the straight-line distance between the two objects. I will determine that number with the simple equation T = D/C. The variable T is time, D is the distance and C is the speed of light (about 300,000 km/s). Because these are all moving targets and various planets are closer and further from Earth at different parts of their orbit these will be round numbers. For distance I will take an average of the apogee and perigee and then compute these based on that number.I am also omitting Centaurs from this list because their erratic orbits make my math meaningless.

The Sun
It would take 8 minutes for a radio signal from the Earth to reach the sun. Incidentally that's also the amount of time it takes for light from the sun to reach the Earth to traverse the same 93 million mile stretch.

Mercury
5 minutes doesn't sound like long but that's slower than a Youtube video on a shared DSL connection.

Venus
The one-way trip takes about 4.5 Minutes, longer than it takes to microwave dinner. It's distance can be anywhere from 26 to 160 million miles so it's time overlaps with Mars.

Earth
It's not zero, it's a minimum of 250 milliseconds for a radio signal to make the round trip from the surface to a geostationary satellite in orbit back to the surface. The Clark orbit is 22,236 mi above sea level so that's still quite fast.

The Moon
Ham radio enthusiasts routinely bounce signals off the Moon just for fun. The round trip takes about 3 seconds.

Mars
At about 33.9 million miles signals take about 21 minutes to arrive. Notably at it's shortest distance that whittles down to 4.5 minutes, which is similar to Venus. They are not equidistant, but the distance varies with orbit enough that the times overlap slightly.

Ceres (dwarf planet)
Ceres is a a rock–ice body  about 590 miles in diameter making up a third of the mass of the main asteroid belt. The one-way trip takes under 40 minutes, but it's still faster than some delivery pizza.

Jupiter
At about 480 million miles away the trip takes about 45 minutes. Famous for it's Jovian radio bursts, you can actually tune in to Jupiter. More here.

Saturn
It takes about 80 minutes for a radio signal to travel either to or from Saturn.  Yes, Saturn emits radio signals too. They have even been monitored by the Cassini spacecraft. The radio waves are connected to the auroras near the poles of the planet similar to those on Earth. You can hear a clip here.

Uranus
It is the last of the planets you can see with the naked eye. A radio signal takes around 155 Minutes to make the trip to Uranus.  I once had a delivery pizza take that long and I got a free 2-liter for my trouble.

Neptune
The most distant true planet, takes a whopping 250 minutes to receive radio signals from Earth.

Pluto (minor planet)
Though recently demoted, it is still a part of our solar system and also our second most massive dwarf planet. A radio signal would travel 3 billion miles and take over 4 hours to get here.

Sedna (Trans-Neptunian object)
It's not alone out there. Around the 8 billion mile mark you will also find dwarf planets Makemake, Haumea and others with less memorable names. With erratic orbits, radio signals take anywhere from 6-7 hours to reach this region.

Eris (dwarf planet)
We are way out now. Eris is almost 3 times as distant at Pluto at over 9 billion miles away. Radio signals take about 7.5 hours to get here.

Voyager Satellite
Presently on the edge of our Solar System, 11 billion miles away our signals now take over 17 hours to reach it. This satellite is now over 30 years old and still operating despite having less computing power or memory than my phone. It's still sending and receiving data in the  8 GHz range and will for years to come.

The Clarke Orbit

Geosynchronous Orbit n. 
An orbital position with an orbital period that matches the rotation rate of the Earth measured relatively to  fixed stars. 

That orbital period isn't a 24 hour day actually. it's what they call a mean sidereal day, which is 23 hours 56 minutes and 4.091 seconds in length. It's not an exactly fixed interval because the Earth wobbles on it's axis, which is measured as two variables called Precession and nutation.  Btu that's getting picky. This is just the time it takes for the Earth to rotate once around its polar axis relative to a distant fixed point. Our sun is not a distant fixed point, so they use the vernal equinox. So far.. not about radio. Don't worry I'm getting there.

The first man-made anything in space was a V4 rocket in 1942. the first satellite was Sputnik in 1957. But the first geosynchronous orbit wasn't achieved until 1964 with the launch of Syncom 3. It was an American communications satellite.

The very idea of a geosynchronous communications satellite is quite old, almost as old as broadcasting. It was first considered and published by Herman Potocnikin 1928. Being an ethnic Slovak in an area now called Croatia... his national identity is up for some debate. But he sometimes used the name Hermann Noordung. He was a real-deal rocket scientist. He attended the University of Technology in Vienna and became a mechanical engineer. He was inspired by the research of Hermann Oberth and went into rocketry.  But Arthur C. Clarke stole his thunder. In a 1945 paper published in Wireless World magazine, titled "Extra-Terrestrial Relays — Can Rocket Stations Give Worldwide Radio Coverage?" More here. He even predicted the frequency band we'd be using. He was only off a few hundred GHz on the future location of the C and Ku bands. Not bad for a guy who writes fiction. the first US TV network to move all it's affiliate feeds to the Ku band was NBC in 1983. Read on:

"It may be argued that we have as yet no direct evidence of radio waves passing between the surface of the earth and outer space; all we can say with certainty is that the shorter wavelengths are not reflected back to the earth... Medium high frequencies go through the E layer twice to be reflected from the F layer and echoes have been received from meteors in or above the F layer. It seems fairly certain that frequencies from, say, 50 MHz to 100,000 MHz could be used without undue absorption in the atmosphere or the ionosphere."

In the piece Clarke first described a geosynchronous orbit as useful for broadcast and relay communications. Because of this much more widely read publication a geosynchronous orbit  is sometimes called a Clarke Orbit. Likewise the region of Earth orbit where near-geostationary orbits are possible is called the Clarke Belt. it is about 22,000 miles above sea level along the equator. To his credit, there are presently over 700 radio communications satellites in a Clarke Orbit. More here.