SpaceX has significantly reduced the size of an “exclusion zone” for its Starlink Internet service in South Africa in a recent update to its coverage map.
A concerned MyBroadband Forum member previously brought the zone to our attention in May 2022, shortly after Starlink first launched the map.
Moving the mouse cursor over the map provides a date for which SpaceX plans to bring the Starlink service to a particular country or region.
In May 2022 and some months after that, hovering over most of South Africa would show Starlink’s estimated arrival time as 2023.
However, that date would disappear completely when moving over a large zone bordered by a jagged circle that included much of the Northern Cape, about half of the Western Cape, and a part of the Eastern Cape.
The cities and towns within the circle included Upington, Ladismith, Beaufort West, and De Aar, with the distance between its northernmost and southernmost tips measuring over 550km.
While it remained unconfirmed at the time, the prevailing theory was that the exclusion zone was to accommodate the Square Kilometre Array (SKA) project near Carnarvon in the Northern Cape.
The radio-astronomy installation’s sensitive antennae operate within some of the same frequency spectrum used by Starlink and would effectively be blinded by Starlink’s satellites should they beam signals within the SKA’s operational area.
The image below is a screenshot of the Starlink coverage map in late May 2022, with the initial exclusion zone shown inside the red ring.
A spokesperson for the SKA recently told MyBroadband the organisation had approached SpaceX about the size of the ring, which was excessive considering the installation’s operational area.
SpaceX appears to have erred on the side of caution, opting to oversize Starlink’s exclusion area in South Africa.
With input from the SKA team, the company has since adjusted the ring to cover a much smaller area surrounding the South African SKA site.
Its northernmost and southernmost points are now only separated by roughly a third of the previous distance.
A large chunk of South Africa which would not have been included in Starlink’s previous coverage — including numerous small towns and farms — now appear to be included in the rollout plans.
Notably, the borders of the exclusion circle now correlate closely with the legally-protected Karoo Central Astronomy Advantage Area, the world’s largest radio quiet zone.
Due to that legislation, the area does not have the typical cellular and radio services available in the rest of the country.
The images below show the updated circle as reflected on the map by 8 July 2022.
SpaceX has seemingly been sensitive to the concerns raised by the radio-astronomy community, who feared the multi-billion-euro SKA project would be rendered moot by Starlink’s satellites.
But Starlink is not the only communications service that could have caused problems for the SKA.
Residents of the farms and small towns surrounding the site can’t use regular cellular services available in the rest of the country due to its status as a radio quiet zone.
But the residents have not been left to fend for themselves, with the South African Radio Astronomy Observatory (Sarao) — a partner of the SKA — subsidising some of the cost of alternative means of connectivity.
That includes paying residents for the installation, terminals, and modems needed to receive broadband coverage from Morclick, which uses Hughes’s YahClick Internet service.
Hughes’s geostationary communication satellite uses the Ka-band frequencies of 26.5–40GHz, while the SKA South Africa dishes operate between 350MHz-15.4GHz.
Customers only have to pay the monthly subscription fee — ranging from R299 to R1,999 — for packages with speeds between 5Mbps and 50Mbps. These also include voice-over-IP lines for phone calls.
The four relatively small towns within the Radio Quiet Zone — Carnarvon, Brandvlei, Williston, and Vanwyksvlei — also get free public Wi-Fi at their libraries.
These sparsely-populated towns had less than 20,000 inhabitants between them during the 2011 census.
The SKA will be the world’s largest radio telescope upon completion. It is expected to help make important scientific discoveries about the universe, including some that could lead to breakthrough innovations with practical applications for humankind.
MeerKAT, an initial phase of the SKA , has already helped produce the best images of the Milky Way’s galactic centre to date.