Will the largest telescope project on Earth become part of China’s Belt and Road Initiative in the US’ absence?

As the global Square Kilometre Array Observatory takes shape, Chinese media has called it a ‘landmark belt and road’ project
But SKAO management and scientists have been quick to correct the claim, saying the telescope network and belt and road are entirely separate

Science

Ling Xinin Ohio

Published: 6:00am, 12 Nov 2023

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The first instruments China has built for the world’s largest radio telescope network will soon be installed in South Africa to help detect signals from the most distant parts of the universe.

Four 15 metre- (49-feet) wide, 20 metre-tall radio dishes, developed by engineers at the 54th Research Institute of China Electronic Technology Group Cooperation in Shijiazhuang, will be put in place early next year at Meerkat National Park, a core site of the Square Kilometre Array Observatory (SKAO).

Being built by scientists and engineers from 20 countries, the SKAO will eventually comprise some 200 parabolic dishes in South Africa and more than 131,000 Christmas-tree-like antennas in Australia, with a combined collecting area of 1 sq km (247 acres).

With sensitivity 50 times higher than any other radio instrument, and a surveying speed 10,000 times faster, the SKAO will be used to study a wide range of phenomena, from the mysteries of dark matter and dark energy to the search for life beyond Earth and test of Albert Einstein’s general theory of relativity.

But with the completion of the new dishes has come intense media coverage in China – along with claims the project is part of the country’s global infrastructure push the Belt and Road Initiative.

“The SKA is a key international scientific research cooperation project of the Belt and Road Initiative,” China Central Television said in a report on August 18.

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In an official documentary aired by state television in the same month, the SKAO was listed alongside Qatar’s World Cup stadium, the China-Maldives Friendship Bridge, Egypt’s new capital city, Indonesia’s 350km/h high-speed rail and Brazil’s ultra-high voltage power line as “the most beautiful landmark belt and road projects” built with China’s assistance.

But to SKAO management and scientists working on the project, this is a new narrative.

“My understanding is that the Belt and Road Initiative is mainly focused on collaboration of regional economic development and transportation with China, and the SKAO is not included in this initiative,” said William Garnier, director of communications, outreach and education.

Wu Xiangping, chief scientist of the SKA China team, underscored the message.

“The SKA has nothing to do with the Belt and Road Initiative,” he said.

“It’s an international cooperation project which was in existence before the Belt and Road Initiative.”

China’s Belt and Road Initiative is an unprecedented plan launched in 2013 to stimulate infrastructure development in, as of today, 155 countries. Some SKAO partner countries such as South Africa, Italy and Portugal are also belt and road members.

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The US was part of the project until 2011. But during the decadal survey to set the astronomy community’s priorities in 2010, “the SKA’s design and cost estimates were very immature, and so there were higher priority projects that sat above it”, SKAO director general Philip Diamond said last week.

As a founding member of the SKAO, China is mainly responsible for developing and delivering a total of 68 state-of-the-art radio dishes by 2027, which involve key technical innovations.

“We required a novel design, called an offset Gregorian, with the receivers sitting at the end of an arm coming from the main structure. The dishes had to be affordable, light but able to point accurately at objects in the sky under significant wind conditions,” Diamond said.

Each dish uses 66 triangular panels to form a three-dimensional hexagonal grid structure, and each triangular panel has a unique curvature, according to its chief designer Du Biao.

“It was a huge challenge to design a system in which the positions of the main reflective panel, the second panel and the receiver need be aligned to an accuracy of less than 1mm,” Du told state broadcaster CCTV last month.

The offset Gregorian design of the dishes had to be able to be constructed to within 1mm accuracy. Photo: Xinhua

China has been actively engaged in the project since the early 1990s. The idea of the SKA emerged from conversations between scientists around the world as to the next big step in radio astronomy, Diamond said.

A team led by the late radio astronomer Nan Rendong proposed to host the SKA site in China by building a significant number of huge radio dishes in the country’s southwest.

“The design was determined to not fully satisfy the science goals of the SKA community, and was not shortlisted. Only Australia and South Africa were on the shortlist in 2005,” Diamond said.

“China has been an immensely valuable and reliable partner in the SKA Observatory,” he added.

Apart from the dishes in South Africa, China is also playing a major role in developing the signal processing system for the antennas in Australia as well as the so-called SKA Regional Centres, which will provide the science community with access to SKA data.

China’s Five-hundred-metre Aperture Spherical Telescope (FAST), which is the world’s largest single-dish radio telescope built by Nan and his team after the bid to host the SKA failed, was complementary to the SKAO, he pointed out.

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“FAST is a wonderful instrument and, although only operational for a few years, is already doing excellent science, such as its contributions to the work using pulsars to detect gravitational waves across the universe,” Diamond said.

Meanwhile, the SKAO covers a much wider frequency range, and can produce higher resolution images than FAST, by adopting the so-called aperture synthesis technology.

“However, FAST’s huge sensitivity makes it a superb detection and survey instrument for the SKA telescopes to follow up, and I expect there will be many joint science programmes in the future,” he said.

When the SKA is completed, China will be assigned about 8 per cent of the observation time, which is in proportion to the financial contribution made by individual founding members.

The seven initial member countries of the SKAO, when it was founded in Rome in March 2019, are Australia, China, Italy, the Netherlands, Portugal, South Africa, and the United Kingdom.