The Square Kilometre Array (SKA) project seeks to build the world’s largest radio telescope. The network of telescopes is being constructed in South Africa and Australia; two countries in the Southern Hemisphere. Space in Africa reached out to Dawid Botha and Isak Theron of EMSS Antennas regarding their perspective on the SKA project, with specific regard to the South African aspect of the project. EMSS Antennas was responsible for the receiver systems, and for the electro-magnetic design and performance analyses of the shape of the offset Gregorian antenna reflecting surfaces for both the MeerKAT and SKA dishes.

Could you please explain and give a brief history of the SKA project?

In a broad sense, the SKA telescope project started as a dream of the international radio astronomy community to build the world’s largest radio telescope – an array of antennas with a planned effective collecting area of one square kilometre. It had to be built in the southern hemisphere to observe the centre of our Milky Way galaxy, leading to bids from countries in the southern hemisphere. South Africa and Australia eventually won the bid to host separate parts of the telescope.

To show the capacity and capability of South Africa to design and operate a radio telescope array, the government-funded building a smaller and locally developed telescope, the Karoo Array Telescope (KAT). As the KAT project gained momentum and increased government support, KAT grew into MeerKAT – literally “more of KAT” and paying tribute to the well-known small mammal that lives in the Karoo region ( the Karoo region houses the telescope project). While the South African government initially conceived the KAT project to substantiate South Africa’s bid to host the SKA, MeerKAT is a science instrument in its own right and currently the most sensitive array telescope in its frequency band in the world.

Could you please elucidate on how the SKA telescope will work and how it is so unprecedented?

Traditionally, radio telescopes were built as one single dish, observing a very narrow bit of the sky with high sensitivity. Subsequently, scientific advances showed that multiple antennas could work together as a system to provide better sensitivity and resolution. Thus, instead of building bigger and bigger single-dish telescopes, you can build one large telescope consisting of multiple smaller interconnected antennas. In such array systems, any two antennas work together, similar to a pair of eyes, to improve the sensitivity and resolve specific detail inside the beam. First, two such antennas form a baseline – the more antennas, the more baselines, the more detail. Secondly, due to the sky’s rotation, the relative positions of the antennas change, providing more baselines. Finally, by combining all the baselines, scientists can build images. 

An exciting feature of radio astronomy is that the relative bandwidth – the ratio between the minimum and maximum frequencies – is much larger than in optical astronomy. For example, the SKA-MID telescope will be working from about 350 MHz to 15 GHz, a ratio of almost 50:1. Such wide bands provide essential additional information.

The sheer size of the SKA is what makes it so unprecedented. Until recently, the largest single-dish telescope was the 300 m Arecibo telescope in Puerto Rico. It is massive but can observe only a limited area of the sky. The SKA will see fainter objects, which means objects further back in time and at a much better resolution.

How did EMSS Antennas join the SKA Project?

EMSS Antennas joined the South African SKA project as electromagnetic experts in 2005. We designed and built the ambient temperature feeds for the experimental demonstrator dish at HartRAO, Hartebeeshoek. Furthermore, we got involved from the start, designing the structure’s reflecting surfaces – including its shape and geometry. EMSS Antennas remained on board as an industry partner to the projects that developed KAT-7, an engineering test-bed for MeerKAT, and then MeerKAT and SKA. We have worked hard to remain relevant and available to the project teams by over-delivering on our promises and growing the company around the anticipated requirements of the projects – at least the electromagnetic parts of it. As the projects grew more extensive, we added more engineers and technical experts to our team to cater to our growing responsibilities on the projects.

If you are to put a date, when do you estimate the project’s completion?

Development work on the SKA telescope began in 2013 while MeerKAT was transitioning into its construction phase. The SKA is an international project – there are different countries with different teams working on various work packages. All of these have now progressed through the design phases to the detail design phase. Preparation for the telescope’s construction is now in full swing after establishing the Square Kilometre Array Observatory (SKAO), an Intergovernmental Organisation (IGO), which will manage and coordinate the construction phase. The SKAO has scheduled construction to commence in 2022 and should take around three to five years, but that is not the end of the formal construction phase. MeerKAT will then be integrated with the new dishes to become one new telescope, SKA1, and then there is commissioning work and early operations before SKA1 can be declared operational. We can probably expect that by 2032.

Have there been any challenges so far in your participation in these projects?

Besides the technical challenges, our involvement in projects of this scale, as a private company, is quite challenging. The biggest challenge for us as a private company is how time translates to money. Public-funded institutions and agencies typically have permanent staff and usually have to budget only for direct project costs. Hence, people are not used to thinking about the cost of time. Engineers from institutes typically only consider the amount it would cost to replace a particular component, without regard for the amount of time spent on the investigation. This is because typically, a separate budget has paid for the engineer’s time. The realities are different in a private company where time is also money –  the private engineer must also receive payment for the time it takes to fix the component. This makes the private company more expensive. As institutes would instead opt for the cheaper alternative, this poses a considerable challenge for us.

Furthermore, these large-scale projects take years to complete and pass through phases of high and low intensity. For us, to grow and maintain the required workforce throughout these phases is quite challenging. We have to find ways to fund our participation throughout the entire life cycle as we are generally required to remain available from start to finish.

A related challenge is that the company grew – in terms of personnel, expertise and equipment – based on the requirements of MeerKAT and SKA. The result is that we now have a highly capable team, which is a great thing, but with its challenges. Radio astronomy is a niche market; very small and highly specialised. Consequently, the challenge is to find other markets that require a similar skillset and infrastructure as what we’ve built up. 

Are there any challenges that the SKA project faces from your perspective? 

The biggest challenge for the SKA project is the distributed nature of the project. The South African government solely funded the MeerKAT as it was a South African project. This meant that the South African team had sole ownership of the trade-off between the different science capabilities and costs. On the other hand, the SKA project is an international conglomeration; this leads to conflicting opinions regarding crucial aspects of the project. At times, there is a conflict of interest between the funders, the builders and the potential users, especially when it comes to trade-offs that the construction must consider. Furthermore, coordinating the development and then constructing the telescope at so many different locations adds additional costs. These are some of the challenges the SKA project faces.

What are the benefits for Africa, and South Africa, in the SKA Project?

There are many benefits to have a project of this nature and magnitude running in your country. One essential benefit is that such a project can inspire the youth to finish their education. It can motivate them to continue into fields such as engineering or science with intentions to join such a project. It is a source of inspiration and motivation to society, the engineers and the country at large.

Industry-wise, the project is keeping the industry on its toes. The industry is pushing and surpassing its limits to contribute to such a highly specialised project, specifically in terms of manufacturing requirements. It is also an opportunity to tap into and further develop the local manufacturing spirit and capacity. The project also created a home for capable, local engineers. These engineers would otherwise have left the country for more challenging endeavours. The project has attracted excellent engineers back to South Africa.

Did the Coronavirus pandemic affect EMSS Antennas? If yes, how

When the South African Government announced the lockdown in March 2020, we were fortunate to be at a remote phase. Stated differently, the lockdown forced us to do the paperwork, which one tends to procrastinate. Coincidentally, when we needed to start with more physical or lab-based work, the government lifted the harsh lockdown. Thus, we were fortunate in terms of the lockdown’s timing. However, the pandemic made it challenging to travel to the Karoo to test aspects of our work on the telescopes. At this point, as researchers are using MeerKAT more and more for science, the gap for on-site testing is closing. Thus, we’ve missed out on a few opportunities to test new ideas. Otherwise, the pandemic did not terribly affect us as a company.

Over the last decade, EMSS Antennas has been integrally involved in South Africa’s MeerKAT project. The company is also integrally involved in the international Square Kilometre Array (SKA) radio astronomy telescope projects. EMSS Antennas maintains an established culture of quality management and product assurance. This is due to the company’s long-term commitments to radio astronomy. The company’s production facility has been ISO 9001 certified since 2017.
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