BRICS science Ministers visit SKA site as MeerKAT foundations are completed
Minister of Science and Technology, Derek Hanekom, headed a delegation of science and technology ministers and senior officials from Brazil, Russia, India, China and South Africa (BRICS) to the Square Kilometre Array (SKA) construction site near Carnarvon, Northern Cape yesterday.
The tour to the construction site was part of the First BRICS Science, Technology and Innovation Ministerial Meeting, which started in Kleinmond on 9 February 2014.
The BRICS ministers and officials received a presentation on MeerKAT and the SKA from Dr Bernie Fanaroff, Director of the South African SKA Project (SASPO), after which they then toured the facilities, including KAT-7 and the underground data centre, which is still under construction.
The Ministers were impressed with the progress made in the construction of the MeerKAT, the South African precursor to the Square Kilometre Array (SKA) telescope, which is to be built in Africa and in Australia. The SKA is an international project to build the largest radio telescope in the world.
The Russian Deputy Minister of Education and Science, Ludmila Ogorodova, expressed the hope that Russia could get involved in the project.
Minister Hanekom remarked that every time he visited the site he was inspired by the rapid progress of infrastructure development at the site and the expansion of the facilities, which made it clear that South Africa would be able to handle the mega-infrastructure needs of the SKA.
The foundations of the MeerKAT are almost complete. The 64th and final foundation for the MeerKAT was poured today at South site. Close to 5 000 m3 of concrete and more than 570 tons of steel were used to construct the foundations over the past nine months.
Tracy Cheetham, general manager for infrastructure and site operations at SASPO, said that the MeerKAT foundations "were constructed to stringent specifications to ensure that the antennae would be exceptionally stable. Even at wind gusts of up to 69 km/h scientists must be able to point the dishes at distant celestial objects in an exact manner, and the antennae must be able to survive wind speeds of up to 144 km/h."
To meet these stability requirements, each foundation consists of eight steel-reinforced concrete piles at depths of between 5 to 10 m, depending on the local soil conditions. A square slab of concrete (5,2 m x 5,2 m, and 1,25 m thick) rests on top of the piles to add further stability. The 32 "holding down" bolts are pre-assembled in a circle to form a steel ring cage, or so-called "bird's nest", into which the concrete is cast.
All other MeerKAT infrastructure should be complete by the end of March this year. "We are on the last leg now," said Cheetham, adding that finishing touches to the Karoo Array Processing Building (KAPB) and the power facility were under way. The KAPB, a specialised underground bunker protected from radio frequency interference, will house all the data-processing racks and the power and back-up equipment required for MeerKAT.
The primary focus for the next two months will be on verifying that all infrastructure functions according to the required specifications. Testing involves cold and hot commissioning. Cheetham explains: "During cold commissioning the power is connected without switching on the equipment. During hot commissioning the machines are turned on and tested for a period of time."
Cheetham also said that the ducting for the fibre-optic cable had been completed, so all that was left to do was for the contractor, Plessey, to pull the cable through and connect it.
MeerKAT facts and figures:
- Leading radio astronomy teams around the globe have already signed up to use the instrument as soon as it is ready. The 64 MeerKAT antennae will later become part of the much larger SKA telescope, which is co-hosted between South Africa and Australia.
- The MeerKAT will be the most sensitive radio telescope in the southern hemisphere until the SKA is completed. Once all 64 antennae are operational, the instrument will be sensitive enough to pick up a cellphone signal from Saturn.
- Each MeerKAT antenna will be 19,5 m high.
- Each reflector (or dish) will be 13,5 x 16 m.
- Each complete antenna (base, pedestal and dish) will weigh 42 tons.
- The configuration (placement) of the antennae is determined by the science objectives of the telescope. There are 48 foundations in the core area, which is approximately 1km in diameter. The longest distance between any two antennae (the so-called baseline) is 8km.
