SKA more than just astronomy

So often with large science projects politicians and some sectors of the general public will criticise the investment. Their argument is that the money should be used to build more houses or to improve the lot of the poor.

When South Africa launched the pathfinder satellite SumbandilaSat, the Minister of Science and Technology was taken to task in an article in one of the Sunday papers accusing the DST of wasting money.

At another media briefing the minster was asked why the government did not rather spend the money to fix potholes. Not short of words the Minister replied “without my satellite how will they find all the potholes!”

The American Space programme had its fair share of similar criticism. In South Africa it is now the SKA.

What if on 14 February 2012, the International Advisory Consortium recommends Australia as the SKA host country; have we wasted the huge investment in developing the precursor KAT 7 system and  the work started on Meerkat?

What the critics forget is that these projects have the major benefit of building a knowledge economy – something South Africa seriously requires.

On the one hand they talk about the brain drain and on the other hand they criticise efforts to create environments that will encourage South Africa’s best brains to remain in the country, attract expertise from overseas and train a new generation of young scientists.

And that is precisely what the SKA projects have done. If  South Africa is not selected as the SKA host, we will still have the Meerkat; which will come on stream around 2016 and provide the world with mega astronomy science opportunities at least a decade or longer before the SKA will come on stream.

As a nation we have already accumulated dividends during the preparation for the SKA bid which was submitted in September 2011.

South African engineers at the MeerKAT project office in Cape Town have taken the lead in the development of new generation astronomy tools such as the ROACH (reconfigurable open architecture computing hardware) boards.

MeerKAT

The ROACH board is a primary building block for digital signal processing system in many next-generation radio telescopes. It is a cutting-edge innovation that enables highly specialised and high-performance computing likely to find its way into many industrial applications.

Designed mainly in South Africa, about 300 of the ROACH-1 boards are already in use at high-tech facilities around the globe.

The prototypes of a much faster and more powerful board, ROACH-2 and 3, have been manufactured. This provides a highly compatible upgrade path for all these facilities and opens up many more possibilities for new installations.

Progress in FPGAs is forecast to hold for at least another four generations, so Engineers working on the project believe that we should at least see ROACH-3, -4, -5 and -6 in the coming years. In fact ROACH 3 is already in the testing phase.

The design of the ROACH board was led from conception to production by engineers from the SKA South Africa Project, with collaboration from many international experts, especially the Centre for Astronomy Signal Processing and Electronics Research (CASPER) at the University of California, Berkeley.

Another example of cutting edge development is cooling of radio receivers used in the KAT7 project. The radio receivers and all their components are cooled to about 70 K (i.e. minus 203°C) in order to reduce the “noise” which is inherent in all radio (and TV) receivers. This allows the telescope to see much fainter objects than it would if the receivers and “feeds” operated at room temperature and were not cooled.

South Africa's Karoo SKA site

Cooling improves the sensitivity of the receivers by more than a factor of 2,5, which in turn reduces the observation time to achieve a given image quality by more than a factor of 6. This improvement in performance will allow KAT-7 to perform early science in preparation for the MeerKAT and SKA.

These preliminary observations will be focused on the needs of the MeerKAT large survey projects, and include imaging of nearby galaxies and work on radio transients and pulsars, for which KAT-7 is well suited.

All seven of the dishes have now been successfully fitted with “cold” radio receivers, signalling the successful completion of the telescope antennas. The first astronomical image has already been made using cold receivers on all seven KAT-7 dishes.

The radio galaxy Centaurus A, whose intense radio emission is powered by a massive black hole in the centre of the galaxy, was selected for this purpose. The resulting image is much more sensitive than the preliminary image made with just four of the KAT-7 dishes fitted with uncooled receivers in 2010.

While all eyes are on 14 February, what ever happens, South Africa’s knowledge economy has already received a huge boost and will continue to grow as the Meerkat project is being completed.