SARAH WILD: SA’s astronomy centres to become one constellation
The Square Kilometre Array project in SA will form the backbone of a national radio astronomy observatory, writes Sarah Wild
The Square Kilometre Array (SKA) project in SA employs 245 people and oversees a budget of billions of rand. From April, it will also form the backbone of a national radio astronomy observatory, absorbing existing facilities into a single entity.
SA’s bid to host the world’s largest radio telescope developed several areas of radio astronomy in the country and on the continent, from the seven-dish Karoo Array Telescope and the 64-dish MeerKAT to the African VLBI Network, which will include radio dishes in a number of African countries.
These will be incorporated into the South African Radio Astronomy Observatory (SARAO), as will the Hartebeesthoek Radio Astronomy Observatory (HartRAO), the stalwart of South African radio astronomy and a major driver of the country’s successful SKA bid.
This follows a longer-term trend to consolidate science programmes: the South African National Space Agency pulled together areas of expertise and facilities, as did the Technology Innovation Agency.
"The idea of a single, consolidated radio astronomy observatory in SA is not a new idea," says Prof Nithaya Chetty, who heads the National Research Foundation’s astronomy cluster. SKA SA is a business unit of the foundation.
"[But] up until now, the bid for the SKA, followed by the building phase of MeerKAT, were highest on the agenda and any movement towards the merger during the past few years would have been a distraction of these main goals."
These goals are finally coming to fruition. The MeerKAT telescope is expected to be completed early in 2018. There are 16 dishes already online, with another 16 expected to be up in the third quarter of 2017.
"As MeerKAT construction comes to an end, we need to deploy engineers and scientists not involved in commissioning and operations to do other things, such as SKA phase one and the African VLBI Network," says Dr Rob Adam, the head of SKA SA.
"It’s a way of using the skills that are in the system to address the challenges of the moment, rather than have them rooted to historic objectives. The last thing we want is for the African VLBI Network to start hiring people and then MeerKAT finishes and you find that people left on the MeerKAT project have nothing left to do."
Although the R3bn MeerKAT is South African-owned and funded, it will be incorporated into the SKA. The SKA will be hosted by Australia and SA, with satellite sites in eight African partner countries. It will seek to answer some of humanity’s most enigmatic questions about the cosmos.
From 2018, another 133 dishes will be added to MeerKAT to form part of S-KA1, which has been capped at €650m.
In Australia, about 130,000 dipole antennas that resemble 2m Christmas trees made out of thick wire, will be constructed as part of SKA-1.
Ghana’s Kuntunse radio astronomy dish will come online in 2017, making the country the second VLBI-capable African country.
VLBI is very long baseline interferometry, in which four or more radio telescopes observe a single celestial object simultaneously and act as one large telescope.
For decades, HartRAO’s telescope was the only one plugged into European networks. But the late Prof Mike Gaylard, a former head of HartRAO, discovered there were many obsolete telecommunications dishes on the African continent that could be converted into radio telescopes.
If you’re sitting with a bird’s eye view [of radio astronomy projects] in the Department of Science and Technology, it makes sense…. It makes no sense to have initiatives dotted aroundDr Rob Adam
Head of SKA SA
Vodafone donated a 32m dish outside Accra to the Ghanaian government for radio astronomy.
A major impetus for the African VLBI Network is to develop radio astronomers and engineers in African countries, particularly the eight African SKA partner countries that are scheduled to house small SKA sites of their own.
"If you’re sitting with a bird’s eye view [of radio astronomy projects] in the Department of Science and Technology, it makes sense…. It makes no sense to have initiatives dotted around," says Adam.
However, there were concerns over the absorption of HartRAO into SKA SA, even though they will both be included into the SARAO.
HartRAO began life in 1961 as the US National Aeronautics and Space Administration’s Deep Space Station 51 and was instrumental in tracking probes outside Earth’s orbit. It specialises in VLBI and a type of science called geodesy, which measures various aspects of Earth, such as continental drift or its distance from the moon.
"As with any merger, there would be concerns. These we have addressed through constructive dialogue during the merger process," says Prof Ludwig Combrinck, acting MD at HartRAO.
These sentiments were echoed by Adam and Chetty, who say the country’s geodesy specialisation will be maintained and preserved.
"With there being a strong political imperative to grow astronomy broadly in SA, not just in the Western Cape and Northern Cape, the location of HartRAO in Gauteng ensures that it has a unique role to play," says Chetty.
He says HartRAO is crucial for training, especially African partner country training.
Initially, the SKA SA was driven from within HartRAO, but eventually became too large to be contained by the small radio astronomy facility.
This amalgamation shows how sprawling radio astronomy has become in SA. From a single dish in the hills of Hartebeesthoek, about an hour’s drive from Pretoria, radio astronomy is attracting scientists and students from all over the world.
This high-technology scientific discipline now employs hundreds of people across the country, trains students inside and outside
SA and is responsible for building infrastructure worth billions of rand.
"The setting up of SARAO indicates the transitioning of SKA SA from an engineering project to a scientific institution, an astronomy observatory," says Chetty.