What The Tech?! Satellite Linking
The development of Transponder carrying Satellites changed the way we consumed media.
While we’ve all heard of the Space Race, which included the Mercury and Apollo projects the importance of the space race for Humanity is often quite misunderstood. The successful carrying of man into space required new materials, mathematics, design and communication methods to go with the all new Saturn V rocket which was scheduled to carry man to the moon. One of the most powerful man made objects, the Saturn V was an engineering marvel in it’s own right, but today we’ll be looking at where the space race began, with man made satellites orbiting the earth.
While few readers are older enough to recall the Space Race, it’s pretty commonly known that it eventuated in what was known as the Sputnik crisis, as the USSR’s Sputnik became the first man made satellite to successfully orbit the earth. This leap forward marked one of the great successes of the space race and proved the viability of receiving a simple signal from space
Sputnik: The First Step
Launched on October 4th, 1957 Sputnik was a polished sphere with two pairs of transmitting antennas extending from the body. Relatively simplistic in design, Sputnik drew it’s power from a small Silver/Zinc Battery bank. This gave an estimated 2 weeks of battery power for it’s payload, which was a simple transmitter. Rated at 1 watt of power output the transmitter worked on two frequencies, using 20.005 and 40.002MHZ as the downlink and transmitting a .3 sec pulse that alternated between the two frequencies. Originally thought to be merely a beacon, it was revealed later on that the beacon would shift slightly according to space conditions, providing the first form of satellite telemetry that was able to be analysed from earth. Sputnik caused both awe and fear at the time, and due to both its frequency selection and orbital inclination was easily receivable by anyone on earth with shortwave receiver, a relatively common piece of equipment at the time. Not to be outdone, the American’s launched their own satellite in January, 1958 with Explorer 1 the first US made satellite to reach orbit. Explorer 1 made history, due to it’s contribution in discovering and charting the Van Allen Belt, an orbital zone with charged particles partly caused by the earth’s magnetic field. This competitiveness would permeate the entire space race until the end with records being set and then broken by both sides throughout.
The Next Step:
While the original Sputnik achievement of a variable mode beacon was rightly noteworthy with the technology of the time, it was simply a matter of time before satellites flew with a full transmit / receive capable payload. However rather than merely being the playground of the military, by the 1960’s private industry got involved with the idea of a Trans Atlantic radio link growing in popularity after being raised early in the decade.
With a Trans-Atlantic link being capable of providing real time voice and video transmission, the possibility of satellite relays provided potentially huge advantages to much of the global population of the time. In the connected world where we can use a satellite phone nearly anywhere and recieve satellite internet from a number of commercial providers it’s easy to forget what a huge evolution this was at the time. If you’d like a bit more of an idea of what it was like back then, the average US wage was around 4000 dollars, Color Television had been launched just 2 years earlier at the beginning of 1960, 80% of houses had landlines and while Trans-Atlantic communications were possible they required the assistance of an operator to help with the complex linking methods of the time. Let’s ask Chat GPT how a call worked back then.
Input: Did Trans Atlantic calls require operator assistance in the early 60's
Output: Yes, transatlantic calls during the early 1960s typically required the assistance of an operator to establish and facilitate the connection. Making an international call, especially across the Atlantic, involved a more complex process compared to domestic calls. Here’s an overview of how transatlantic calls were handled:
1. Dialing Assistance: Direct dialing capabilities were limited for international calls during that time. To initiate a transatlantic call, the caller would typically reach out to a local operator or the international operator and provide the desired destination and phone number.
2. Operator Assistance: The operator would then assist in establishing the connection by manually connecting the call through international switchboards and undersea cables. The operator would coordinate with the appropriate overseas operator to complete the call.
3. Call Routing and Time Zones: Transatlantic calls required careful coordination due to the time zone differences between North America and Europe. Operators had to consider the appropriate time and routing to ensure the call was connected during the desired time slot and reached the intended destination.
4. Communication Channels: Transatlantic calls were generally carried over undersea telephone cables that spanned the Atlantic Ocean. These cables were specifically designed to transmit voice signals across long distances.
5. Cost and Duration: Transatlantic calls were relatively expensive and often billed at high international rates. The duration of the call was also a factor, as the charges would accumulate based on the time spent on the call. This led to a preference for shorter conversations due to the costs involved.
6. Call Quality and Reliability: The quality and reliability of transatlantic calls depended on various factors, including the condition of the undersea cables, atmospheric conditions, and the technical infrastructure in place. Call quality could vary, and disruptions or static interference were not uncommon.
It’s important to note that the introduction of communication satellites, such as Telstar 1, played a significant role in improving transatlantic communications. These satellites enabled direct and more efficient communication between continents, reducing the reliance on operators and enhancing the speed and quality of international calls.
The First: Telstar 1
The first western steps in achieving this goal were taken in 1962 with the launch of the Telstar 1 relay satellite.
A collaborative project between western companies like AT&T, Bell Labs and the French National Postal Telegraph, Telstar was a large bird with a diameter of 88cm and a weight of close to 80 kg. With a 34 foot large, inflatable balloon antenna the onboard transponder worked in the 4–6 GHZ range, providing both video and phone linking capabilities with over 600mhz of bandwidth, a large capacity for the time.
Successfully launched in July 1962, it’s first test was conducted the very next day with a private signal relay carrying imagery of a flag outside Ander Earth Station. Just two weeks later the satellite went live with it’s first signal, carrying a public broadcast across the Atlantic that featured both NBC and BBC news anchors.
However the life of Telstar was to be short lived with the satellite damaged by the atmospheric nuclear explosions of Starfish Prime. Suffering extensive damage to it’s transponders, control uplink and onboard housekeeping unit Telstar continued to operate until November when the command link became non responsive. While a remote reset was successfully conducted, the problems were unable to be repaired and Telstar went quiet in February 1963 although it still orbits the earth today.
The Next Gen: Intelsat:
While there’s no accepted time frame as to what the Gen 2 satellites were, in our opinion the next big step was with IntelSat and its launch of IntelSat-1 or “Early Bird”. Launched in 1965 the technological advances were immediately noticeable, with Early Bird significantly smaller than it’s predecessor with it’s mass just 34kg and it’s size measuring 76 x 61 cm.
Early Bird packed a punch however, due it’s 40 watt transponder and ability to provide near instantaneous contact in voice, video and digital modes. Due to its launch inclination of 28 degrees and Geosynchronous orbit, Early Bird kept station over the Atlantic ocean and provided services for over 4 years, including extensive coverage of the lunar Apollo program.
IntelSat-1 / Early bird gets a nod in this feature due to it proving the viability of both Geosynchronous Satellites and long distance communication relays. If you aren’t entirely sure how a Geosynchronous orbit works, we’ve included a nice little explanation for you in the visual below, but basically the satellite’s orbit is the same duration of the earth’s meaning that a geosynchronous satellite is capable of monitoring the same place on earth as they carry out their orbit.
Geostat.gif Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation… en.wikipedia.org
Iridium:
The functionality of satellite communications provided a later revolution of technology, allowing communications by HF radio to become a secondary form of communication rather than the default standard. As how it usually works in the capitalist world by this point, other entrepreneurs saw the value and and began testing the viability of private satellite technology as a paid service. The culmination of this technology gave us the Iridium cluster, and while it wasn’t a broadcasting technology like the earlier birds, it did provide global communications reach for anybody who could afford, and was inclined to pay for it.
Originally conceived by Motorola in the late 80’s the design of the Iridium cluster was implemented to provide true, global voice and data bandwidth to parties anywhere on the globe. Whilst making the most of electronic miniaturization Iridium birds were still huge, at over 690 kg launch weight.
Working in a cluster of 77 satellites to provide the needed coverage, the first Iridium bird flew in 1997, and throughout the project the additional satellites were launched with Chinese, Russian and American rockets all used to launch the constellation at various points.
With the system unable to go online until all satellites were airborne, this goal was completed in mid 1998, when the first call within the network was achieved. True global coverage would take a little longer to transpire, with this objective deemed complete in 2002.
The system, which operated on 1.2ghz was plagued with issues from the start with poor reception indoors and large expensive and propitiatory handsets required to access the system. While this was alleviated somewhat in the later 2000s with the launch of the follow on IRIDIUM-NEXT satellites the system struggled throughout it’s life, eventually bankrupting the original owners.
Starlink and Future Tech:
While satellite relays provided the world with connectivity in a pre internet world, the next step in relay technology would be the provision of fully internet capable services via satellite. While the earliest satellites came with the ability to receive and pass through data transmissions which continued to evolve with the technology, the availability of global satellite based internet took until the late 2010s to come to fruition.
Constellation technology, which involved fleets of satellites working together originated in the United States, where the technology was envisaged in the Brilliant Pebbles program. Brilliant Pebbles, an incredible story in its own right was part of the Strategic Defense Initiative, which provided space based ballistic missile defense.
With the project falling victim to cost blowouts and the post Cold War peace dividend, constellation technology was shelved until the new millennium when Space X looked at it to provide it’s Starlink service.
Differing from the Satellites of old by both size and the overall number of the craft within the constellation, Starlink envisaged a truly global footprint from it’s birds, with high speed internet available to users in any location.
With thousands of satellites within the cluster, Starlink is a genuine constellation with inter-satellite linking and phased beam forming in the Ka and Ku bands used to provide continuity of services, mitigating the orbital effects of a low orbit cluster.
Starlink also differs from the satellites of old in the way it delivers it’s services. Rather than directly broadcasting to a handset like the birds of old, a terminal system is used. This provides connectivity within an area, allowing multiple users to receive a connection via a router, as you would with a typical terrestrial based system.
Known internally as Dishy McFlatface the system gained notable recognition in 2022 when thousands of receivers were sent to Ukraine to assist in maintaining connectivity during the Russian invasion.
We hope you’ve liked this month’s What the Tech?! This recurring monthly article focuses on integral pieces of technology that have shaped our world.
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