A unique signature Space stations are globally identified by acronyms (signatures) given to them by the international space agencies. Hartebeesthoek is known as HBK. The acronym also identifies the antennas at each ground station, such as HBK-2. In contrast, therefore, to the Bard’s contention that “a rose by any name will smell as sweet”, an antenna is not just (another) antenna. Each antenna is unique, with a ‘signature’ that clearly identifies the ground station where it is located.
During its lifetime, the CSIR Satellite Application Centre’s antenna farm was integral to South Africa’s broader space initiatives. The expertise and facilities at the Hartebeesthoek ground station became indispensable in supporting national and international space initiatives.
major satellite manufacturers, operators and space agencies worldwide benefited from SAC’s TT&C services.
LOCATION, LOCATION
THE ANTENNA FARM
Hartebeesthoek’s location, some 70 km west of Pretoria and 40 km north-west of Johannesburg, in the Magaliesberg mountain range, places it on the outskirts of the Cradle of Humankind, one of South Africa’s World Heritage sites.
The idea of creating an antenna farm at Hartebeesthoek took root during a SAC strategic planning session in 2001. At the time, the site housed four antennas (12 m, 10 m, 5.4 m and 13.2 m).
The position of the site at the southern tip of the African continent gave SAC ‘first acquisition’ status as a ground station for satellites launched from Cape Canaveral in the US. The Hartebeesthoek location was well-chosen and ideal for providing international clients with tracking, telemetry and command (TT&C) services for their geosynchronous and polar orbiting satellites. Most
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The Antenna Farm | The SAC Story: Commemorating 50 years
Almost 10 years later, at the end of the SAC era in 2010, the number of antennas had increased to 19, with varying dish sizes and slew rates that accommodated a number of frequency bands and tracking modes.
THE GROUND STATIONS SAC also installed, operated and maintained ground stations for clients. An example is the ORBCOMM ground station, which consists of two identical
radomes1 with high-frequency planar-arrays2 on which the antennas were mounted. ORBCOMM is a specialist US satellite communications company with a fleet of micro-satellites in low-Earth orbit. ORBCOMM clients can remotely track, manage and control assets from almost anywhere in the world.