The SKA Project is an international endeavor to build the world’s largest radio telescope, with a collecting area and ultimately sensitivity that will be orders of magnitude higher than any other instrument that exist today. South Africa has already demonstrated excellence in the field through its designing and building of KAT7 and MeerKAT. The KAT7 telescope, with all seven dishes completed and producing scientific images paved the way for MeerKAT. The MeerKAT telescope (a 64 antenna array and official pathfinder to the SKA) is progressing well and set to start limited science observations in 2016, coming up to full science capability in 2017.
The SKA Project is an international endeavor to build the world’s largest radio telescope, with a collecting area and ultimately sensitivity that will be orders of magnitude higher than any other instrument that exist today. South Africa has already demonstrated excellence in the field through its designing and building of KAT7 and MeerKAT. The KAT7 telescope, with all seven dishes completed and producing scientific images paved the way for MeerKAT. The MeerKAT telescope (a 64 antenna array and official pathfinder to the SKA) is progressing well and set to start limited science observations in 2016, coming up to full science capability in 2017.
Using thousands of receptors in three unique configurations, the Square Kilometre Array (SKA) will afford astronomers unprecedented access to the sky, enabling them to survey its entirety thousands of times faster than any current system. To be co-located in Africa and in Australia, it will boast an image resolution quality 50 times greater than that of the Hubble Space Telescope to give an unprecedented scope of observations. The SKA Organisation itself is headquartered at Jodrell Bank Observatory, near Manchester, UK, and was established in December 2011 as the central control hub for a global team who will be building the SKA over the coming decade.
Upon completion, the South African MeerKAT radio telescope will be an array of 64 interlinked receptors, meaning the complete antenna structure with the main reflector, sub-reflector and all receivers, digitisers and other electronics installed. It is currently under construction some 90 kilometres outside the small Northern Cape town of Carnarvon, and is a precursor to the Square Kilometre Array (SKA) telescope. MeerKAT will be integrated into the mid-frequency component of SKA Phase 1 (SKA-mid) and thus become an integral aspect of the largest and most sensitive radio telescope in the world, as MeerKATat Project Manager Willem Esterhuyseexplains. “MeerKAT is the 64 antennae array that we are currently building, which is expected to be completed in 2017. It will be, upon completion, the most sensitive radio telescope in the world in L-band, until SKA-mid is completed. SKA mid will be a total of 197 antennas (64 MeerKAT antennas combined with an additional 133 antennas).”
The scale of the SKA marks a considerable leap forward in terms both of the engineering and of the research and development involved in building and delivering a radio telescope, and when operational it willdeliver a similarly remarkable increase in the capabilities of the science that can be done with the instrument.“The primary return of an instrument like this is the science,”continues Esterhuyse. “There are very compelling scientific cases to be made for building these telescopes –this ranges from exploring the formation of stars and galaxies in the early phases of the universe and studies into phenomena like dark energy and dark matter.”The importance of an instrument with such a vast scope as SKA becomes clear when Esterhuyse explains the information it will be able to collect. “In simple terms, the bigger collecting area that you have available, the weaker the signal that you can detect – basically you have a more sensitive instrument. As the signals that are detected become weaker, the further back you are able to look in time. For example, if you emit a signal it starts travelling out in a sphere, so as you go further out in that sphere fewer photons pass through it, and thus a weaker signal is present.”
The MeerKAT project is creating a large group of young scientists and engineers with world-class expertise in these technologies, while as Esterhuyse explains, the technology is cutting-edge. And like little which has come before it. “We had the opportunity to learn from what other people have done before us and by utilizing the advances in technology combined with some clever engineering we managed to improve significantly on what was initially considered to be the achievable standard. If you look at radio telescopes, and specifically arrays the baseline until now has been the VLA in new Mexico. When we specified MeerKAT that was the level of performance that we considered to be the baseline. We realised that we needed to be able to at least match the capabilities of that facility, which is in the Northern hemisphere, but now we are confident that we will improve on that baseline. With MeerKAT in the Southern hemisphere new scientific research opportunities open up, which we can optimize with the increase in sensitivity. SKA mid (of which MeerKAT will form about one third) will be a significant performance step up, but until then MeerKAT will be a world-class instrument that will allow us to perform hugely exciting science observations –truly a national facility to be proud off.”
The project is currently in what is termed the industrialisation phase, ever progressing toward its expected completion in mid-2017. “We’ve got four antennas up,”says Esterhuyse, “and quite a number of others in progress, which will go to the site soon. Internally, we’ve set up facilities to produce our digitisers and the receiver manufacturing and correlator PCB units has been contracted. The control and monitoring and data processing software we are developing in-house, building on what has been done for KAT7. Having shown that we can meet our specs and that our performance modelling of the system has been done accurately, it’s a matter now of rolling out the technology and commissioning systems on schedule.”At the moment it is intended that MeerKAT will be integrated into SKA towards 2022, a gap of around five years which will allow a series of scientific projects to be undertaken. “There are senior scientists around the world who already have programmes approved for MeerKAT, in terms of time allocation and the kind of science they are looking to do. We now need to press on and finish MeerKAT – we will be executing the last proposals that we have and then MeerKAT will be integrated into SKA Phase 1.”Many of these leading scientists are already involved with SKA on science through the seven-dish MeerKAT precursor array KAT-7, the world’s first radio telescope array to feature composite antenna structures. These dishes were completed by December. While the initial intention with KAT7 was that of an engineering testbed, it is now doing routine science, which has worked out very well as relationships and data interfaces are established with scientists who will be working on MeerKAT. This has certainly assisted in getting MeerKAT architectures defined and should allow for a smooth transition from engineering to science operations”, says Esterhuyse.
In the construction of MeerKAT there has also been a strong focus on maximising local content in order to maximize the benefit of MeerKAT to South Africa and South African industry. “We focussed strongly on a high local content for MeerKAT, because we wanted local industry to benefit from it, both in terms of the work they did and the technology they developed. With the antenna contract there is a contractual 75% local content requirement. Additionally, considering the operations of instruments like MeerKAT and SKA there is significant benefit to being the entity that operates the instrument for the next 50 years that provides high level sustainable job opportunities for many South Africans as the yearly operational budget of a facility like this is a significant percentage of the construction budget.”Infrastructure tenders have also been awarded locally for most of the infrastructure components, including roads, buildings, power reticulation, construction camps, an air strip and the KAT 7 and MeerKAT Building Management System.
Apart from the science return there are also significant other benefits associated with MeerKAT. The opportunities that the project looks set to bring to the country as a whole are themselves highly significant, particularly in changing the view held by many academic institutions of South Africa and the human capital development it will entail. “Even just looking at MeerKAT now, we have already awarded close to 700 bursaries since 2005”, details Esterhuyse, “in various areas from technician level through Masters, PHD, post-doctoral up . Most of the bursaries awarded have been in the science and engineering field an area we believe will have a significant impact on the economy. Even if we cannot provide work for every single one of these graduates ourselves, what develops is a workforce skilled in science and engineering, a workforce that can go into industry and really make a difference to the economy of the country.”
This closely echoes the sentiments expressed by Prof. Justin Jonas,Associate Directorof the SKA South Africa Project, who added that: “the selection of Africa to host the mid-frequency SKA array, and the incorporation of the locally designed and built MeerKAT into the first phase of the SKA, is a clear statement by our international peers that Africa has become a destination for world-class fundamental scientific research and cutting-edge technology development,”while Tony Beasly, Director at the National Radio Astronomy Observatory (NRAO), commented after visiting the site that,“MereKAT is the most exciting cm-wave telescope build underway on the planet, and SKA-SA is doing a top-notch job managing the project.”South Africa is now being seen as the premier destination for cutting edge science, and MeerKAT is helping to establish Cape Town as the hub of high-tech endeavours.
There is also what Esterhuyse terms a “reverse brain drain”effect at work, whereby many South Africans are returning from overseas to work on this project. “We’ve also had very senior scientists who have moved to South Africa to be involved in MeerKAT, some of those taking up senior positions at South African universities,”he continues, “so the knowledge transfer that occurs in that environment is massive.”The experience gained by SKA SA allows it to play a major role in SKA development, and will prove hugely beneficial to the project as a whole, particularly in its ability to attract leading scientists and engineers to Cape Town.“The people involved in this project have had access to individuals who have been at the forefront of radio astronomy for many years, and a lot of them are at the point now where they are close to, if not the best, in the world. They may not be as well known, but technically they are as good as the most prominent names in the field, and only through their work on the MeerKAT project could they have acquired these types of skills. I fully expect many of these to be the well-known names that will become role models and mentors for future generations.”
Ultimately, the success of a project of this scope comes down to the people involved in its execution. “We have a highly talented team, which is focused on becoming the best in the world,”explains Esterhuyse. “We have a very simple saying, that IP walks on two legs. That’s exactly the case here – a lot of our senior guys have been here since the very beginning. Of course, in between people have been added to the team and many of them have made tremendous contributions, but one of the key things is that for the people that started all of this, it was so much more than a job, and today most of them are still here. The continuity this brings makes a huge difference and has been crucial to our success.”