SKA decision may be political

By Leon Engelbrecht, ITWeb senior writer

Johannesburg, 30 Apr 2008

SA and Australia are technically closely matched to host the 1.5 billion euro Square Kilometre Array (SKA) radio telescope. However, the final decision may be the result of arcane politics, according to those in the know.

Both countries are proposing sites near a town called Carnarvon - SA`s being in the Northern Cape and Australia`s being about 600km north of Perth.

MeerKAT project leader Anita Loots says: "Technically, the two sides are very similar. Unless there are any fatal flaws, there is no technical reason we cannot do it.

"We have to prove through continued delivery on MeerKAT that we can build complex technical instruments, and secondly, that we have the skills in scientists and engineers to look after the instrument. People compare it to the World Cup and Olympic bid, but the big difference is we will run SKA for 50 years, not six weeks."

Who decides?

The decision will only be taken in three years, says SA SKA project leader Dr Bernie Fanaroff. The SKA involves 30 research institutions in 15 countries, including SA.

"The decision will primarily be that of the funders and governments, but they will obviously consider the input of the site and engineering committee [on which SA has two seats]."

Fanaroff says much of the funding comes from the European Union and European member states, which will translate into them having a "very important role" in the final decision.

"But the politics is too complicated," Fanaroff says. He adds that astronomers think both sites are viable.

By 2011, when the decision is made, both sites will also have existing infrastructure. The South African site will host the seven-dish Karoo Array Telescope and the MeerKAT (more-than-KAT), an 80-dish telescope.

The Australian Boolardy site will by then be home to the Australian SKA Prototype and the Mileura Wide-Field Array, a joint project between the Massachusetts Institute of Technology, the Harvard-Smithsonian Center for Astrophysics, the Raman Research Institute and an Australian consortium of universities. Australia has so far invested $52.7 million in its bid.

Criteria

Officials in the Department of Science and Technology say the US is pushing Australia as host, while Europe prefers SA, perhaps for time zone issues or perhaps in antipathy of the US move. SA`s technology may also be more mature.

Loots says Australia is pursuing a high-risk approach, whereas SA is following an incremental methodology. This may be key as the SKA will operate 24 hours a day, all week for at least 50 years after switch-on.

Loots and Fanaroff says a decision must still be made on how robust the SKA will be, and what percentile of dishes and computing capacity must be available at any given time: the higher the percentage, the more durable the technology needs to be and the more it will cost.

Fanaroff suggests 95% of the 3 000 to 5 000 dishes and their associated collators will have to be available for space science at any given time.

What`s it for?

The SKA Web site notes that most of the current-generation radio telescopes were built 10 to 30 years ago. "For radio astronomy to progress, a new telescope with one hundred times the collecting surface of existing telescopes will be needed in about 10 years` time."

The site says the SKA "was conceived as a new international project to meet the future needs of radio astronomers".

It notes "one of the prime objectives of the SKA is to probe the so-called 'dark ages`, when the early universe was in a gaseous form before the formation of stars and galaxies. At present, astronomers do not have the necessary tools to observe radiation from this period of the universe, which extends from about 300 000 years till one billion years after the 'Big Bang`."