The Square Kilometer Array has Gotten the Official Green Light to Begin Construction
In Australia and South Africa, there are a series of radio telescopes that will be soon joined by a number of newly-constructed facilities to form the Square Kilometer Array (SKA). Once established, the SKA will have a collecting area that measures a million square meters (close to 2 million square yards). It will also be 50 times more sensitive than any radio telescope currently in operation, and be able to conduct surveys ten thousand times faster.
During a historic meeting that took place on June 29th, 2021, the member states that make up the SKAO Council voted to commence construction. By the late 2020s, when it’s expected to gather its first light, the array will consist of thousands of dishes and up to a million low-frequency antennas. These will enable it to conduct all kinds of scientific operations, from scanning the earliest periods in the Universe to searching for extraterrestrial intelligence (SETI).
At its core, the SKA relies on a process known as interferometry, where light from cosmic sources is gathered by multiple telescopes and then combined to create high-resolution images. For radio telescopes, this technique has the added advantage of allowing for observations where only a subset of the full array is available. With such a large collecting area, the SKA will allow for all kinds of revolutionary science.
A Huge Effort
The SKA consists of four “precursor facilities,” which include the MeerKAT and the Hydrogen Epoch of Reionization Array (HERA) in South Africa, and the Australian SKA Pathfinder (ASKAP) and Murchison Widefield Array (MWA) in Australia. Beyond these, there are also the “pathfinder” facilities located outside of these two countries, consisting of the Allen Telescope Array in northern California and the Low-Frequency Array (LOFAR) in the Netherlands.
These facilities are divided into two networks designated SKA-Low and SKA-Mid, which describe the radio frequency range they will cover. The decision to approve construction comes on the heels of two major developmental milestones for the SKAO. First, there was the publication of two key documents last year, the Observatory’s Construction Proposal and Observatory Establishment and Delivery Plan, and an executive summary of both.
The documents are the culmination of over seven years of design and engineering work by more than 500 experts from 20 countries, the purpose of which was to test the technologies needed to build and operate the largest radio telescope array ever built. Second, there was the creation of the SKAO as an intergovernmental organization, which took place earlier this year. As SKAO Director-General Prof. Philip Diamond said in a recent SKAO press release:
“I am ecstatic. This moment has been 30 years in the making. Today, humankind is taking another giant leap by committing to build what will be the largest science facility of its kind on the planet; not just one but the two largest and most complex radio telescope networks, designed to unlock some of the most fascinating secrets of our Universe.”
“I would like to thank everyone who has contributed to making this possible over the past decades, from the early inception of the project until now, and in particular all the teams who have worked so hard over recent years and powered on through a pandemic in very difficult circumstances to meet deadlines and make this milestone possible. I would also like to thank our Member States for their vision and the trust they’re placing in us by investing in a large-scale, long-term research infrastructure at a time when public finances are under intense pressure.”
This organization now accounts for eleven international consortiums that represent more than 100 research labs, universities, and companies from all sixteen Member States who were responsible for designing the necessary hardware, software, and infrastructure. These include Australia, Canada, China, France, Germany, India, Japan, Italy, the Netherlands, Portugal, South Africa, South Korea, Spain, Sweden, Switzerland, and the United Kingdom.
Construction is expected to last until 2028 and will be followed by the first science operations in the early 2030s. The cost of the entire project, including constructing the two telescopes, associated operations, and business-enabling functions is projected at €2 billion ($2.38 billion USD) over a nine-year period (2021 – 2030). The first significant activity on site is scheduled to take place early next year, but procurement of major contracts will begin immediately.
Over the next few months, the SKAO will issue about 70 contracts to all of its Member States, which will then put them for competitive bidding locally. The SKAO anticipates that once they have started gathering light, the two arrays will remain scientifically productive for 50 years or more. Dr. Catherine Cesarsky, Chairperson of the SKAO Council, expressedher gratitude to all those who helped get the SKA to this pivotal point in its development:
“I would like to add my thanks to the members of the SKAO Council and the governments they represent. Giving the green light to start the construction of the SKA telescopes shows their confidence in the professional work that’s been done by the SKAO to get here, with a sound plan that is ready for implementation, and in the bright future of this ground-breaking research facility… Today’s commitment by Member States is a strong signal for others to get aboard and reap the benefits of participation in this one-of-a-kind research facility.”