WRITTEN BY JACK SLATER

What we see in the sky at night is nothing short of messages from the beginning of time as the light from the very nearest galaxy to our own left it before our human species even evolved. To achieve a deeper sense of enlightenment we need to uncover and study the nature of the universe to better understand ourselves first. We spoke with Managing Director, Dr. Bernie Fanaroff.

MeerKAT is cutting-edge and the

project is creating opportunities

for a large group of young

scientists and engineers with

world-class expertise in the

technologies which they did not

have previously. This will prove

to be crucial in the next 10 – 20

years in the development of

super-computing which will have

an impact on data transport,

the creation of large sensory

networks, radio software and

imaging algorithms.

“MeerKAT will be the most

sensitive radio telescope in the

southern hemisphere until SKA

comes online,” Bernie is quick to

point out, “It is by this credit that

leading radio astronomy teams

“South Africa has

already demonstrated

its excellent science

and engineering skills

by designing and

starting to build the

MeerKAT telescope

as a pathfinder to the

SKA”

SKA PROJECT

In South Africa, astronomers want to build the most powerful telescope ever, to see back to before the first stars and galaxies formed into the very source of all that is.

“The Square Kilometre Array (SKA) will be a radio

telescope,” explains Bernie, “Instead of seeing light

waves, it will create images via radio waves.”

This is a landmark occasion as the majority of the SKA - the full

dish array and the dense aperture array - will be built in Africa. The

core - i.e. the region with the highest concentration of receivers - will

be constructed in the Northern Cape Province, about 80 km from

the town of Carnarvon which is incidentally the same site where the

MeerKAT is being constructed. The sparse aperture array which is

the low frequency array will be put together in Western Australia.

“South Africa has already demonstrated its excellent science and

engineering skills by designing and starting to build the MeerKAT

telescope as a pathfinder to the SKA,” Bernie reveals, “The first seven

dishes, KAT-7, are complete and have already produced its first

pictures it has created a bit of a media storm and we’ve attracted

great interest internationally.”

In fact more than 500 international astronomers and 58 from

Africa have submitted proposals to do science with MeerKAT once

it is complete.

One of the reasons is that the technology being developed for

Endeavour Magazine | 35

around the globe have already signed up to use the instrument as

soon as it is ready.”

The concrete for the first MeerKAT antenna foundation was

poured on Wednesday 14 August 2013 at South Africa’s SKA site

in the Karoo. This is the first of 64 similar foundations that will be

constructed for this telescope over the next nine months with each

foundation consisting of 78 m³ concrete and nine tons of steel.

“Designing a foundation for a high-tech telescope is complex and

challenging since it has to meet a set of stringent requirements,” Tracy

Cheetham, general manager for infrastructure and site operations at

SKA South Africa explains. “The foundations must ensure that each

of the 19-m high antennas with its 13.5 x 16 m main reflector will be

exceptionally stable and able to point accurately at distant celestial

objects at wind speeds gusting to 69 km/h as well as survive wind

speeds of up to 144 km/h. Another challenge for the design team was

to ensure that each antenna was carefully earthed and would not be

damaged in the event of a lightning strike.”

In order 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 over five meters wide and over one meter thick rests on

top of the piles to add further

stability. Upon that thirty two

“holding down” bolts are pre-

assembled in a circle to form a

steel ring cage, which is called

an engineering “bird’s nest”, into

which the concrete is then cast.

“This first foundation will

now be verified through a series

of load tests to ensure that all

specifications have been met,”

Cheetham says. “Getting this

absolutely right is critically

important for the science to be

done with this instrument, and

will also inform the construction

of foundations for other SKA

dishes to be built in the Karoo.”

Since 2005, the African SKA

Human Capital Development

Programme has awarded close to

400 grants (2012) for studies in

astronomy and engineering from

undergraduate to post-doctoral

level, while also investing

in training programmes for

technicians. Astronomy courses

are being taught as a result of

the SKA Africa project in Kenya,

Mozambique, Madagascar and

Mauritius (which has had a

radio telescope for many years)

and are soon to start in other

countries.

MeerKATThe MeerKAT array,

currently taking shape in South

Africa’s Karoo region, is a world-

class radio telescope designed

to do ground-breaking science.

It will be the largest and most

SKA PROJECT

sensitive radio telescope in the southern hemisphere until the Square

Kilometre Array (SKA) is completed around 2024. Via MeerKAT, South

Africa is playing a key role in design and technology developments for

the SKA.

Close to 100 young scientists and engineers are working on the

MeerKAT project. Based at the engineering office in Cape Town, and

at universities and technology companies across South Africa and

Africa, these researchers interact closely with SKA teams around the

world. In collaboration with South African industry and universities,

and collaborating with global institutions, the South African team has

developed technologies and systems for the MeerKAT telescope,

including innovative composite telescope dishes and cutting-edge

signal processing hardware and algorithms.

Prof Justin Jonas, Associate Director: Science and Engineering at

SKA South Africa, is very excited about the implications of the SKA

site decision for the role that South Africa’s MeerKAT telescope will

play in the future of the SKA. “The decision recognises MeerKAT as

a key instrument that will make up one quarter of SKA Phase 1 mid-

frequency array, and the science planned for SKA Phase 1 is very

similar to the MeerKAT science case - just much more ambitious,”

he explains. “Our researchers and students who participate in the

MeerKAT surveys have a huge advantage. They are well placed to

enter SKA Phase 1. They have the opportunity to become science

leaders in future SKA projects.”

Up to 2016 South Africa will be constructing the 64 MeerKAT

dishes in the Karoo and construction on 190 SKA Phase 1 dishes

should start more or less when MeerKAT is complete. “The design

of the SKA dishes is not yet final, but they should look similar to

the Gregorian-offset dish design chosen for MeerKAT,” Prof Jonas

expects.

KAT-7 (seven-dish MeerKAT precursor array)

The seven-dish MeerKAT precursor array, KAT-7, is the world’s

first radio telescope array consisting of composite antenna structures.

South Africa is currently building the Karoo Array Telescope, or

MeerKAT, a mid-frequency ‘pathfinder’ or demonstrator radio

telescope, alongside the SKA core site.

The first seven dishes of the local precursor instrument - known

as KAT-7 - were completed by December 2010 and are now being

commissioned.

It is the world’s first radio telescope with dishes made of fibre

glass. KAT-7 is an engineering prototype for the 64-dish MeerKAT,

but the world’s scientists see it as a useful instrument in its own right,

and they are keen to switch it on for doing science as soon as possible.

“KAT-7 has already delivered images of the Centaurus A, a galaxy

14-million light years away,” Bernie concludes.

“Designing a foundation for a high-tech telescope is complex and challenging since it has to meet a set of stringent requirements,” Tracy Cheetham, general manager for infrastructure and site operations at SKA South Africa explains. “The foundations must ensure that each of the 19-m high antennas with its 13.5 x 16 m main reflector will be exceptionally stable and able to point accurately at distant celestial objects at wind speeds gusting to 69 km/h as well as survive wind speeds of up to 144 km/h. Another challenge for the design team was to ensure that each antenna was carefully earthed and would not be damaged in the event of a lightning strike.”

32 | Endeavour Magazine

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