/ 9 March 2015

SKA Organisation gives smaller design the green light

Ska Organisation Gives Smaller Design The Green Light

The Square Kilometre Array (SKA) phase one will now move into its final pre-construction phase, smaller than initially anticipated but within the EUR650-million budget cap. Construction will begin in 2018.

The giant telescope, which will comprise thousands of antennae in Australia and Africa, with the core in South Africa, will be the largest scientific experiment in the world and will attempt to answer some of humanity’s most enigmatic questions, such as: Is there other life in the universe, how do galaxies form and what is dark matter?

However, it was initially envisioned that the telescope would be on one continent and, following the site decision in May 2012 when it was decided that the telescope would be split between South Africa and Australia, scientists and engineers have been working on a design that would accommodate telescopes in both countries, while still getting the maximum science out of the instrument.

As part of the bid to host the giant telescope, Australia and South Africa developed precursor telescopes, named Askap (Australian Square Kilometre Array Pathfinder) and MeerKAT respectively. The second dish of the 64-dish MeerKAT was erected in February and the entire telescope is expected to come online in 2017.

“Presently in its design phase, the international project, currently consisting of 11 nations, has been engaged over the last 20 months in a rigorous and extremely challenging science-driven, engineering process with teams from around the world working to refine the design of SKA1,” the SKA Organisation said on Monday, following its board meeting at the weekend.

The outcome was that there would be two major facilities in each country, SKA Organisation director-general Phil Diamond told Mail & Guardian.

* South Africa’s 64-dish MeerKAT will be extended to “about 200”, slightly less than the 256 envisioned in SKA1.

* In SKA1, Australia was meant to have “several hundred thousand ‘dipole’ antennae”, but this has been reduced to 130,000. The ‘dipoles’ look like mini-cellphone masts, about a metre in height.

* Diamond said that the SKA Organisation was negotiating a takeover of Askap, the 36-dish Australian pathfinder, in a few years, but that this would not take place now.

The Mail & Guardian reported last year that the SKA1 “wish list”, which would be the maximum specifications of phase one with all the bells and whistles, would put phase one at €1.8-billion, three times the budget cap. SKA Organisation director-general Phil Diamond called this a “headline number” and a “naive addition of the maximal costs submitted by the various design consortia”.

However, the latest design would allow SKA1 to remain within the budget cap, Diamond said.

Asked to clarify the alteration to the design, SKA South Africa director Bernie Fanaroff said that, although SKA1 would be smaller, it would not affect its ability to do good science. “It may take a bit longer [to perform the full suite of observations], but it won’t be compromised. We’re hoping that things like improved receivers will help us get some of the time back.”

Regarding the smaller SKA1, Diamond said that due to the “phased” approach, it was possible that parts left out of SKA1 could be incorporated in SKA2, which has not yet been designed.