The Fuss about SKA

with Nickey Mannya

This will allow many independent observations at the same time. The joint receiving area of all these dishes and panels will add up to approximately one million square metres. The SKA will require super-fast data transport networks and more powerful computing than ever before.

South Africa and Australia are the only two countries remaining on the shortlist to site this mega telescope. A final decision on the site is expected by 2010 and construction should start in 2014

If built in South Africa, the core of the SKA will be in the Karoo region of the Northern Cape Province. Outer stations will fan out from the core in a spiral pattern, with proposed remote stations in several other African countries and neighbouring islands (Botswana, Ghana, Tanzania, Kenya, Madagascar, Mauritius, Mozambique and Namibia). The ramifications of this project if won by South Africa, are continent wide.

SA and Australia are technically closely matched to host the 1.5 billion euro Square Kilometre Array (SKA) radio telescope. However, the final decision may be the result of arcane politics, according to those in the know.

Both countries are proposing sites near a town called Carnarvon – SA's being in the Northern Cape and Australia's being about 600km north of Perth.

MeerKAT project leader Anita Loots says: “Technically, the two sides are very similar. Unless there are any fatal flaws, there is no technical reason we cannot do it.“We have to prove through continued delivery on MeerKAT that we can build complex technical instruments, and secondly, that we have the skills in scientists and engineers to look after the instrument. People compare it to the World Cup and Olympic bid, but the big difference is we will run SKA for 50 years, not six weeks.”

The decision will only be taken in three years, says SA SKA project leader Dr Bernie Fanaroff. The SKA involves 30 research institutions in 15 countries, including SA.

“The decision will primarily be that of the funders and governments, but they will obviously consider the input of the site and engineering committee [on which SA has two seats].”

Fanaroff says much of the funding comes from the European Union and European member states, which will translate into them having a “very important role” in the final decision.

Officials in the Department of Science and Technology say the US is pushing Australia as host, while Europe prefers SA, perhaps for time zone issues or perhaps in antipathy of the US move. SA's technology may also be more mature.

Loots says Australia is pursuing a high-risk approach, whereas SA is following an incremental methodology. This may be key as the SKA will operate 24 hours a day, all week for at least 50 years after switch-on. Loots and Fanaroff says a decision must still be made on how robust the SKA will be, and what percentile of dishes and computing capacity must be available at any given time: the higher the percentage, the more durable the technology needs to be and the more it will cost.

Fanaroff suggests 95% of the 3 000 to 5 000 dishes and their associated collators will have to be available for space science at any given time.

MeerKAT will be one of the world's premier mid-frequency radio astronomy facilities that will put South Africa at the cutting edge of radio astronomy.

The telescope will be constructed in phases to ensure the best value for money and sound technology choices. The first phase, a one-dish prototype, has already been constructed at the Hartebeesthoek Radio Astronomy Observatory (HartRAO) in Gauteng. KAT-7, a seven-dish engineering testbed and science instrument near Carnarvon in the Northern Cape Province, will be commissioned towards the end of 2009. The full array of 50 or more dishes should be ready to do science by 2012. A high speed data transfer network will link the telescope site in the Karoo to a remote operations facility.

The Karoo region of the Northern Cape Province is ideal for radio astronomy, because it is remote and sparsely populated, with a very dry climate. There is minimal radio frequency interference from man-made sources such as cellular phones, broadcasting and air traffic.

MeerKAT science will explore celestial mysteries such as cosmic magnetism, the evolution of galaxies and large-scale structure in the universe, dark matter and the nature of transient radio sources. It will study pulsars and allow scientists to do novel astrophysics and astrobiology experiments.


South African engineers and astronomers are working closely with teams around the world on the cutting edge technology required to make MeerKAT work.

Visit www.ska.ac.za for more

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