The CSIRO's 64-metre Parkes Radio Telescope, also known as 'The Dish', was commissioned in 1961, so we are fortunate to be able to celebrate its 60th anniversary on October 30.
Subscribe now for unlimited access.
or signup to continue reading
At the time, it was the most advanced radio telescope in the world, incorporating many new innovative design features that have since become standard in all large dish antennas.
Through its early discoveries it quickly became the leading instrument of its kind in the world.
Today, 60 years after it was commissioned, it is still arguably the finest single-dish radio telescope in the world.
It is still doing world-class science and making discoveries that are shaping our understanding of the Universe.
In the lead up to the anniversary this Sunday, CSIRO's operations scientist, John Sarkissian OAM, walks us through how The Dish came about, and all that the telescope has achieved over the past 60 years.
In Part 2, we look at how Taffy Bowen turned his dream into a reality.
For several years in the early 1950's, Taffy Bowen had been thinking about the next phase in the development of radio astronomy.
By 1954, with the closure of the Dover Heights field station complete, Bowen was convinced that the best all round instrument to continue CSIRO's pioneering efforts in radio astronomy was a large, fully steerable dish antenna, or Giant Radio Telescope (GRT), in the 60 - 76 metre (200 - 250 foot) range.
Bowen estimated that the capital investment for the GRT would be somewhere in the order of $1 - 2 million USD , but this was beyond the budget of the CSIRO at the time, so Bowen sought other sources of funding.
It was then that Bowen's wartime contacts came to the fore.
Many of his colleagues during his radar days were in positions of authority and influence in the Australian government and in the large philanthropic organisations of the United States.
Bowen was determined to draw on this network of contacts to provide the funds to make his vision a reality.
Funding the GRT
In August 1952, Bowen wrote to Vannevar Bush, the President of the Carnegie Institution, to enquire if funds could be made available for his GRT.
The early success of radio astronomy in Australia had attracted the attention of Vannevar Bush and Alfred Loomis, a trustee of the Carnegie Corporation.
Both knew Bowen through wartime friendships and admired his drive and enthusiasm (Bush had been President Roosevelt's science advisor and the man responsible for initiating the Manhattan project).
In due course, in May 1954, the Carnegie Corporation announced that it would provide USD $250,000 towards the partial funding of the GRT in Australia.
With the funding from the Carnegie Corporation in hand, planning for the project could begin in earnest.
In early 1955, the CSIRO set up an Radio Astronomy Trust with Richard Casey, who was by then the Minister for External Affairs and Minister in Charge of CSIRO, serving as its chairman.
Casey was very sympathetic and made strong representations to the Prime Minister, Robert Menzies, to support the project, and Menzies agreed on the proviso that at least half of the total costs were to be raised from private sources on a 50:50 funding basis.
In 1955, Bowen again visited the United States, seeking support from other philanthropic organisations.
He received a sympathetic hearing from the Rockefellar Foundation and its President, Dean Rusk.
Two aspects contributed to this positive response. Firstly, the fact that Richard Casey was the chairman of the Radio Astronomy Trust and was well known to Dean Rusk (from Casey's time in wartime Washington), facilitated matters considerably.
Secondly, Lee DuBridge, President of Caltech, was a trustee of the Rockefellar Foundation and a great supporter of the GRT.
Casey met with Rusk in December 1955, during which Rusk agreed to contribute USD $250,000, the same amount as the Carnegie Corporation.
Dean Rusk later became familiar to Australians as the US Secretary of State in the Kennedy and Johnson Administrations in the 1960s.
Further funding of $107,000 USD was obtained from the Rockefellar Foundation in December 1959, and a further grant of $100,000 USD from the Commonwealth government was received in January 1960 to cover a shortfall in the funds.
When combined with the $55,000 USD from private Australian donations and the matching funds from the Commonwealth government, the total cost of the GRT eventually came to $1,420,000 USD.
Designing the GRT
With the initial funding secure from the Carnegie Corporation, work began on designing the GRT in 1955.
A publicity booklet titled "A Proposal for a Giant Radio Telescope" was released in 1955, which was intended to stimulate the interest of engineers and contractors with many unusual design concepts presented.
The eventual breakthrough in the final design came about by accident.
During a trip to the UK in 1955, Taffy Bowen was introduced to the famous chief engineer of Metropolitan-Vickers, Barnes Wallis.
Wallis was well known as the inventor of the "bouncing bombs" of dam busters fame during the Second World War, and over lunch one day, Bowen discussed the plans for the GRT with Wallis who agreed to submit a few ideas.
He immediately set to work on a design concept, and a few months later, Wallis submitted his plans, which included several innovative design features, such as mounting the dish from the centre, like an inverted umbrella.
The British firm Freeman Fox and Partners (FF&P) was engaged to perform the detailed design study, they took Wallis' ideas and developed them.
Radiophysics engineer, Harry Minnett, was appointed the Radiophysics representative at FF&P to supervise the design and drive system.
READ MORE ABOUT THE DISH'S 60TH ANNIVERSARY: Where it all began
The senior partner of the firm, Sir Ralph Freeman, was the engineer who had designed and built the Sydney Harbour Bridge.
From the outset, both FF&P and Wallis favoured an alt-azimuth mount because of its structural simplicity.
From the size/cost curve a diameter of 64 metres (210 foot) was agreed, and was optimised to operate at a radio wavelength of 10cm.
To minimise the effect of detecting ground radiation, the telescope had a 30-degree elevation horizon.
The design study had taken three years to complete, which was much longer than originally planned, however, the excellence of the design was recognised by all, vindicating the extra time it took to get it right.
Choosing the Site
The site chosen for the GRT was near the town of Parkes in New South Wales, about 350 km west of Sydney.
Several technical requirements were taken into consideration when choosing the site.
The ideal location
- Be geologically stable to provide a solid foundation
- A mild climate free of ice and snow
- Low average wind speed all year round
- Be a few hours' drive from the Radiophysics headquarters in Sydney
- Had to offer a very low level of radio interference
During a comprehensive four-year search, several sites across NSW were considered and shortlisted, including sites near Camden, Canberra, Cowra, and Parkes.
During a specially convened meeting at the Radiophysics headquarters in March 1958 to decide the matter, Parkes was the unanimous choice.
The then Mayor of Parkes, Cec Moon, was enthusiastic and saw the possibilities for the town.
He played a major role in bringing the telescope to Parkes. The Council offered to cover some of the cost of the roadbuilding and earth works.
It also established a radio quiet zone around the site, limiting industrial development to minimise radio frequency interference.
This tipped the decision to Parkes.
The chosen site was located about 20km north of the township, on a 400 acre parcel of land known as Kildare', which was owned by local farmer Australia "Austie" Helm and his family.
