11 December 2006
South Africa’s second satellite, SumbandilaSat, will be launched in early 2007 from a submarine off the coast of Russia and carried halfway around the world by a modified intercontinental ballistic missile before being released into low-earth orbit.
The 81-kilogram micro-satellite will orbit the earth at a height of 500 kilometres for between three and five years, giving South Africa affordable access to space technology.
Its images will enable scientists to monitor disasters such as fires, floods and oil spills, and deliver useful data on climate, dam levels, population density, crop yields and vegetation.
SumbandilaSat will be South Africa’s second satellite after SunSat, which was built by Stellenbosch University staff and postgraduate students and launched into low-earth orbit by Nasa in 1999, remaining operational for almost two years.
State-of-the art payload
Although the new satellite will be around the same size as SunSat, technological advances mean it will be far more capable, carrying a state-of-the-art imaging payload.
According to Allan Duggan, writing in Popular Mechanics, SumbandilaSat’s “six-band onboard multispectral line-scan camera and video sensors, equipped with three different lenses, will scan the Earth at varying angles”.
The resulting high-resolution images will be transmitted to a ground tracking station at the Council for Scientific and Industrial Research’s (CSIR’s) Satellite Applications Centre at Hartebeeshoek bordering the Magaliesberg mountains in Gauteng, with backup stations at Overberg Test Range, Bredasdorp and Stellenbosch University in the Western Cape.
“The satellite is equipped with 24 gigabytes of non-volatile memory, allowing it to stream about 6GB of image data every day per unique located ground station,” Duggan writes.
The satellite was designed and built by Stellenbosch-based SunSpace, the company that developed out of the success of SunSat. According to Business Day, SunSpace completed construction of the satellite in September and has since put the craft through a series of trials to check its ability to withstand extreme temperature and vibration.
Business Day reports that SumbandilaSat’s launch, originally planned for December, was delayed until the European spring to allow for better weather. The new launch window period is in April or May 2007.
“Technically, it’s ready, it’s passed all the tests,” department spokesman Nhlahlha Nyide told Business Day.
The government has invested R26-million in the project, which is being managed by the University of Stellenbosch.
While the university also trains postgraduate students in, and conducts research into, satellite engineering and software development, the CSIR’s Satellite Applications Centre will be responsible for operating, tracking and monitoring the satellite.
Essential monitoring tool
According to the Department of Science and Technology, rural communities stand to benefit from the information gathered by SumbandilaSAT, whose observations will inform decision-making in land use and agriculture, natural resource and disaster management, and infrastructure and urban planning.
“Space assets” such as satellites are no longer merely a matter of prestige for a country but “have become essential tools,” the department said in a recent statement.
“We need to understand the earth system to improve human health, safety and welfare and to protect the environment, reduce disaster losses and achieve sustainable development.”
According to Professor Sias Mostert of the University of Stellenbosch, satellites now monitor “almost all aspects of the world’s climate systems,” including sea and land temperatures, wind, rainfall and vegetation cover.
Town planners also use satellite images to help tackle problems such as traffic congestion, illegal building and lack of recreational sites, says Mostert.
Mothibi Ramusi, manager of the Satellite Applications Centre at the Center for Scientific and Industrial Research, says the satellite’s communications payload will also enable it to provide certain telecommunications services based on the “store and forward” principle.
For example, Ramusi explains, as the satellite passes over South Africa, users with receiving stations will be able to send and receive e-mails. In addition, local data – such as data on dam levels – can be transmitted from ground sensors to the satellite for forwarding on to central authorities.
According to Popular Mechanics, SumbandilaSAT will take to the sky during a five-day launch “window” starting on 20 December.
SouthAfrica.info reporter and BuaNews