A Brief History of SANSA's Earth Observation

Americas contribution to the International Geophysical Year (IGY)in 1958 was Project Vanguard managed by the American Naval Research Laboratory (NRL). The aim of Project Vanguard was to launch the world's first 'artificial' earth satellite, and to determine its orbit accurately thereby yielding completely new information about the earth's gravity field and shape.

For this purpose the NRL designed and manufactured a precision radio interferometer tracking system, code named Minitrack. The minitrack system was capable of determining a radio source in space accurately to one thousand of a degree.

Seven of these Minitrack systems were deployed in North and South America so as to form an 'electronic fence' through which a satellite transmitting in the 136 MHz to 137 MHz frequency band could not pass without being detected.

The Satellite Applications Centre had its origins in 1958 when the national Telecommunications Research Laboratory (TRL) of the CSIR agreed to operate and maintain such a Minitrack in South Africa. South Africa was strategically situated relative to the launch facilities in Cape Canaveral, and would give early confirmation that a satellite launched from Cape Canaveral was indeed in orbit.

The Minitrack system was installed with the help of engineers from the NRL and became operational in January 1958. It is history that the Soviet Union launched SPUTNIK 1 in October 1957. The Joburg Minitrack Station - as it was known, tracked its first project Vanguard satellite, code named 1958 Beta, in February 1958. Although the emphasis was on determining the position of the first satellites accurately, this soon became of secondary importance as more sophisticated instruments were placed in orbit to measure a host of physical and geo-physical phenomena. To receive telemetry data from instrumented satellites soon became the primary function of the Minitrack Network - including the 'Joburg Minitrack Station'.

It soon became apparent that the grounds of the Railway College at Esselen Park was not an ideal electromagnetic environment in which to receive weak telemetry signals from space, due to the close proximity of high voltage lines and electric mains. With the IGY something of the past, the American National Aeronautics and Space Administration (NASA) was established and space research gained rapid momentum. The 'Joburg Minitrack Station' became part of NASA's worldwide satellite tracking and telemetry network operated by NASA's Goddard Space Flight Centre (GSFC)in Greenbelt Maryland.

In 1960 operations were transferred from Esselen Park to Hartebeesthoek and the Joburg Satellite and tracking and Data Acquisition network station (JOBURG STADAN) was born. This became one of the busiest network stations in the GSFC satellite tracking telemetry and command (TT&C) network. It was eventually equipped with three receiving links at 136 MHz and later 5 band and two powerful VHF transmitting systems.

Old TT&C equipment, decommissioned in the 90's.

A TT&C operator working on old equipment

During its 15 years as a GSFC satellite TT&C network station, the JOBURG STADAN received more than eight million minutes of data recorded on half a million reels of tape, tracking 400,000 satellite passes, sent millions of commands, and supported over 250 NASA launches.

1998 Ku Band at Hartebeesthoek.

NASA ceased operation in South Africa at the end of October 1975. The CSIR then used the remaining equipment and a core group of personnel to establish the Satellite Remote Sensing Centre (SRSC) in 1976 for the reception of geo-information from satellites. The first images were received from a European meteorological satellite, METEOSAT in 1978, followed by LANDSAT in 1980, and ERS 1 and 2 in 1994.

The first meteosat image recieved at hartebeesthoek, 1977.

In 1983 the SRSC became part of the worldwide tracking network of the French National Space Agency, CNES. The SRSC has supported over 100 Ariane launches from Kounou in French Guinea.

1983: Became part of the CNES network.

During the restructuring of the CSIR in 1988/1989, the SRSC became the Satellite Applications Centre (SAC), a program of the CSIR. Since then, the SAC grew to provide TT&C services to a multitude of international space agencies and aerospace companies as well as providing remote sensing data and value added products to the geo-information sectors.

In 2008 the South African government's Department of Science and Technology (DST) set out to develop a national Space Agency. The SAC was identified as one of the key centres to form what is today known as the South African National Space Agency (SANSA). Today the grounds at Hartebeesthoek are known as Space Operations. Space Operations is home to the TT&C and Earth Observation team. In 2013 SANSA's Earth Observation team will relocate to Pretoria in order to better represent SANSA and engage with stakeholders.

Article adapted from Botha,W - courtesy of SANSA, Space Operations