Look carefully at the facsimile cover sheet below and you will see two dishes at Jamesburg. One is in front of the other slightly obscuring it, but two dishes are certainly shown. There was only one that was ever constructed. Why? An artist’s whim? No!
It goes back to the time that the station was being planned. Pure and simple, they did not know whether a geostationary satellite was going to work and this was the alternative. A series (constellation) of low earth orbit satellites in polar orbit.
The fax sheet above refers to BER tests between Hong Kong and Jamesburg conducted via the Pacific Ocean Intelsat on 19th Sept 1989. They still used the cover sheet that was designed in the early days.
The fall back position for a polar orbit constellation of satellites was simply that one dish would track a satellite from north to south and before it disappeared another would appear over the horizon and the second dish would acquire the signal and track it. Meanwhile the other dish would disengage from its track and return to the north ready to acquire the next satellite.
This game would need to be played at all sites around the pacific and there would be a point where all stations in range would switch to the new craft. This also meant that the Jamesburg dish is a very high speed large dish capable of tracking low earth orbits – unusual for a dish of this size (97 feet in diameter – 30 m). One benefit would be that the constellation would also be used over other oceans and land masses as they orbited.
Intelsat was launched in a stable geosynchronous orbit and the second dish was never installed otherwise Moree and other satellite stations would have also needed 2 dishes. I expect the planning for Jamesburg well and truly preceeded that of the Australian Moree earth station. I have had long conversations with Jack Ramey (listed on the fax). about the dish’s capabilities. Jack has been amazingly helpful and I expect that Jack is hoping that it may someday go back into service.