A landmark radio astronomy project is about to unveil its first prototype dish antenna.
Tomorrow, researchers and engineers with the Square Kilometre Array (SKA)—to be the largest radio telescope in the world—will inaugurate the dish at a test site in Shijiazhuang, China. And they expect to erect a sister prototype in South Africa by April. But funding, technical, and bureaucratic challenges have forced planners to downsize the first phase of the SKA—envisioned to include hundreds of dishes in South Africa and thousands in Australia—and delay completion by at least 2 years, to 2026.
Still, SKA officials are thrilled to see the first prototypes appear. “It’s great to actually see metal being deployed,” says Phil Diamond, director-general of the SKA Organisation, based in Manchester, U.K. “This is the culmination of a 5-year design program.”
When complete, the SKA will be much more sensitive than current radio telescopes that collect electromagnetic signals from space. In the first phase, Australia is expected to host some 130,000 dishes designed to collect low-frequency signals, while South Africa will host nearly 200 midfrequency dishes. Planners hope to substantially increase those numbers in a second phase. Researchers will use data collected by the linked arrays to investigate a wide range of questions, including what happened just after the big bang and whether there is other life in the universe.
The €674 million project, now backed by 10 partner countries, originally hoped to begin construction in 2018. But that date was pushed back to 2020 as a result of organizational hurdles, including the creation of an organization to oversee the SKA Observatory, and funding troubles forced a downsizing. Diamond says those issues have been resolved, but that countries still need to sign the legal documents.
In the meantime, the first prototype midfrequency dish, built by Chinese company CETC54 in collaboration European partner companies, will be unveiled tomorrow in China, to be joined within a few months by a second prototype in South Africa. The Chinese-led consortium’s design won out against Canadian and South African competitors, in part because of the dish’s superior structural integrity. The midfrequency dishes will need to survive the telescope’s 50-year operational life, so they will be rigorously tested.
Researchers expect to spend at least 6 months, and likely more, testing the two prototypes before attempting to move to full-scale production. “They’re at the start of a long road,” says Tony Beasley, head of the U.S. National Radio Astronomy Observatory in Charlottesville, Virginia. (The United States is not a SKA partner.) “You need to make sure design is correct.”