Satellite Communications & Microwave Hopping

Please send us your experiences, etc.

Larry Bloomfield

(circa 1963)

During the launch of one of the Syncom satellites, this is me measuring the Range and Range Rate of the spacecraft.  This is particularly important as the distance to a geosynchronous space craft and the rate at which that distance changes determines its geosynchronisity.   

There are only a finite number of satellites out there.  No doubt there are more in cue to be launched and positioned.  It would be interesting to know what the demands will be in the future for channel space on those highflying communications devices.  With compression we can get much more on a single bird, but with multicasting, Hi-Definition, etc., the need will gobble up bandwidth like a pack of sharks on a feeding frenzy.  I often wonder if Dr. Harold Rosen or any of the rest of my associates with Project Syncom ever thought what we were doing back in 1963-64 would ever evolve into this?  We sure thought it was hot when we were able to tell within three meters of where Syncom II & III were (at 22,300 miles) back in those days.  I wonder how much more accurate they are today?  

[The following was written in March 1998 and never published until now:]

Hughes, Me and the "Birds" 

            The year was 1962 and I was just finishing off my first hitch in Uncle Sam's Canoe Club as a 2nd Class Electronics Technician.  With no particular job prospects and the economy not being in the best of shape, my Dad suggested I do another tour, providing I could get an assignment to my liking.  When the assignment detailer said he had a duty station that dealt with the space program, I had illusions of working with everything from Buck Rogers' equipment to a James Bond spy-in-the-sky device.  It truly intrigued me so I raised my hand for another six. 

              I was assigned to the U.S. Naval Research and Development Satellite Communications Group with orders to work with Project Advent, a detachment assigned to a ship to be commissioned at the Philadelphia Naval Ship Yard, USNS Kingsport.  I no sooner arrived in the City of Brotherly Love than I was handed another set of orders back to California for school at the Space Technologies Labs in El Segundo.  It was while I was at STL that I found out that Project Advent, a joint military satellite effort, was canceled and was being replaced by Project Syncom.  It seems that Advent was supposed to have been the first geosynchronous satellite.  When I first heard this, I didn't have a clue as to what geosynchronous was, much less spell it.

              At a distance of approximately 22,300 miles out in space, it would take an object 24 hours to orbit or rotate around the earth, thereby giving the impression that it hovered over a given spot.  It wasn't hard to figure out that this would eliminate any expensive tracking equipment.   The antenna could just point at the device and communicate.  Another advantage, at that altitude, each spacecraft saw 40% of the earth's surface.  It would only take three to cover the earth.

              We four STL students had a chance to compare notes and this is when I found out the background as to why Advent got scrubbed.  As a joint military project, each branch had their own ideas as to what they wanted in the spacecraft.  At that point there wasn't a booster big enough to get the payload off the ground. 

              It wasn't GE, but Hughes that had a better idea and came to the rescue.  Dr. Harold Rosen, who headed up a group of engineers called Project Syncom, had developed a very simple, lightweight transponder which would do everything necessary to prove it all could be done and it all weighed only 78 pounds.

              Before I go on, not all communications satellites are equal.  The road to successful, reliable communications was long and involved.  The first attempt at communications aided by a device in space was with Score, a relatively low orbit  device that, in 1958, transmitted a Christmas message from President Eisenhower to the world.  The Advanced Research Projects Agency designed Score.  The second was Courier, an U.S. Army project.  It was launched in 1960 and was also a low orbit device, which received signals from earth, taped them and retransmitted them when it was over the target area. 

       Echo-1, a 100-foot diameter metallic surfaced ball, was launched on August 12, 1960.  Many transcontinental and transoceanic experiments and demonstrations were made with this passive-reflector device until it lost much of its efficiency as a radio-reflector due to the gas, which had inflated it, had leaked out.

       Telstar-1, launched on July 10, 1962 was the most impressive device to date.  It was a joint AT&T - NASA project.  The first communications satellite NASA had been involved with.  Telstar-1 provided direct exchange of American and European television programs during its six months of operation.  Other Telstars were launched, but because they had only a 90-minute orbits, required expensive tracking equipment.

              On December 13, 1962, Relay-1 was launched.  This was a joint RCA - NASA project that had a 2-½ hour orbit.  Many of the same test were done with Relay as were done with Telstar, but after being in service only a short time and due to power supply problems, NASA found it impossible to use one of Relay-1's two amplifiers, so it was abandoned. 

              Enter Project Advent, which, before completion, gave way to Syncom.  There were three agencies involved with Syncom: NASA, the United States Army Satellite Communications Agency (USASCA) and Hughes.  USASCA was a joint military effort, who successfully saved most of the training and equipment abandoned with the demise of Project Advent.  It was used with Syncom.

              What made Syncom unique, besides being geosynchronous, was a special design feature.  In its body was fitted a small rocket call the apogee motor, used to inject the spacecraft into orbit when it reached its apogee at 22,300 miles of the initial trajectory.  Syncom was also fitted with ten small vernier rockets used to correct further the final velocity.  Two nitrogen jets were employed to obtain and maintain the required orientation and position above a point on the ground.

              Along with forty some other sailors on the USNS Kingsport in Lagos, Nigeria,  I employed the skills I had learned at STL: Syncom-1 was launched on February 14th, 1963.  My job was to determine the range or distance to the satellite and the rate at which this range changed.  Too close to the earth and the orbit would be less than 24 hours.  Conversely, too far and it would take longer than 24 hours.  Drift was not acceptable unless it was on purpose to reposition the bird.  During the 5 hours it took to reach apogee, test were run and the spacecraft worked fine.  When the apogee rocket was fired, that was the end of Syncom-1.  Long-range telescopes could see debris in geosynchronous orbit.

              By using wave fronts of predetermined, very accurately generated tones, we were able, using Doppler techniques, to determine the distance to the spacecraft within a meter or so.  Not bad at 22,300 miles, but this accuracy would have been at any distance using this technique.  Hughes was next door to where I worked.  They did all the command functions to the bird.

              After a brief retrofit of equipment and some rethinking, it was back to Africa and the launch of Syncom II on July 26th, 1963.  Everything went according to plan.  The bird went into geosynchronous orbit and tests were conducted all hours of the day and night.  Before we left Nigeria, we hosted the first telephone call between heads of state, Al Haji Sir Abubaker Blewa, Prime Minister of Nigeria and President John F. Kennedy.   It is interesting to note that both were assassinated shortly thereafter while still in office.

              Because we were portable, it was decided to test the fringes of the coverage area.  For that we went up into the Mediterranean Sea from Spain to Lebanon, stopping in Italy.   The earth stations stateside we worked with were in Ft. Monmouth, and Lake Hurst, New Jersey.  Later we were to work with Ft. Dix and Camp Roberts.

              While in Italy, I met my wife-to-be, while she was on vacation.  I mention this because the crew was permitted to make calls to their friends and families through the bird, when our test periods were done.  We even had little cards like QSL card we sent to those we called.  I probably was the first person ever to court his girl through a geosynchronous satellite. 

              The only discrepancy with Syncom II was that since it was launched from Cape Canaveral, some 28-degrees north latitude, the bird had a 28-degree north and south excursion in a 24-hour period.  This was no problem, but it wasn't true synchronicity as was desired.

              There was a third bird in the wings and, rather than let it just sit there, it was decided to put it up too.  Kingsport went back for more retrofitting.  With all the new "mods" in place, we left the east coast, when through the Panama Canal, stopped off in San Diego and Hawaii, finally taking station on the tropical paradise of Guam.  It is interesting to note that on our way to Guam, we passed the AT&T Cable ship, Long Lines while they were laying the first transpacific cable. What we were doing would make the cable obsolete!  We used Syncom II and the AT&T pacific cable to help in the launch of Syncom III. 

              Instead of one transfer orbit, it was decided to use several and during the equatorial crossings make corrections so the north/south excursions would be eliminated, putting it into true synchronous orbit. Launched on August 19, 1964 from Cape Kennedy, Syncom III didn't reach its "fixed" position until September 10th, after a series of maneuvers that put it in near perfect geosynchronous orbit.

              Many hour of testing were done on both Syncom II and III.  Many "firsts" were logged on one or the other of those first two working Syncoms.  Inm retrospect, it's sort of déjà vue: with the winter Olympics coming from Japan (1998).  We carried the first summer Olympics, 34 years ago in 1964, through a geosynchronous satellite, Syncom III for the first time.  Those 1964 summer Olympics were held in Japan too. 

              Hughes is still in the Satellite business.  As for me, who knows, I do like my DSS and its several hundred channels, while I set back and  reaping the fruits of those early labors.  

END

Note: I will be adding additional comments and some pictures from my own personal experiences at a later date.  When I learn more about how to build web pages, I may even include some tape recordings of the actual launches of Syncom.  Until then, please use these links below to learn about the world's first geosynchronous satellite and a time in my life when I had one heck of an experience and good time.  Thanks for sharing in my adulation!

Satellites and the Sun

 

Since the very first geosynchronous satellite went up in 1963, users of these devices are subjected to a unique phenomenon that occurs twice a year. Geosynchronous is a term used to describe the orbit of satellites which rotate around the earth in a 24-hour period at an altitude of approximately 22,300 miles (~35,888 KM) above the equator in synchronization with the rotation of the earth, there by appearing to someone on the earth to be stationary or hovering at a given spot above the earth. They are sometimes called Geo-stationary.

Because of their orbit, there are two times a year all receive/transmit dishes and any given satellite are in alignment with the sun. This takes place in the spring, usually in March and in the fall,, usually September of the year. Because solar activity has many kinds of radiation, radio noise across the entire spectrum being one of them, it impacts satellite communications. The effect usually lasts for about a week. It begins its week-long cycle for only a brief (few seconds) period of time, increasing daily to outages lasting as long as half an hour or more. It then decreases in time until the phenomenon goes away for about six months.

 

The only way to avoid this kind of outage from the satellite you normally use is to switch to a different satellite at a very different orbit during the outage, if you have that option available; if not there is nothing you can do! These solar outages will occur at different times of the day from any one given location on the earth with satellites “parked” in different orbits; the closer together orbits, the more concurrent would be the effect in comparison.

 

Feel free to e-mail any other questions of this type to: webmaster@tech-notes.tv

 

 

Links

http://www.fredonia.edu/department/communication/schwalbe/cm350/tsld173.htm

http://www.fredonia.edu/department/communication/schwalbe/cm350/sld167.htm

http://www.tbs-satellite.com/tse/online/sat_syncom_2.html

http://www.aipress.com/jackpages/syncom.html

http://www.tbs-satellite.com/tse/online/sat_syncom_3.html

http://roland.lerc.nasa.gov/~dglover/sat/syncom.html

http://www.rocketry.com/mwade/craft/syncom.htm

http://satamerica.com/orbit7.html


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