Address/Description
CSIRO Parkes Observatory, 585 Telescope Road, Parkes NSW
Approximately 172ha, 18km North Northeast of Parkes on Telescope Road, being the area comprising the whole of New South Wales Land Parcel Lot 1 DP445477.
The Parkes Observatory is located 20 km north of the town of Parkes, NSW. The main telescope at the Observatory is the Parkes radio telescope, Murriyang which was completed in 1961. The telescope comprises of a 64-metre diameter moveable dish on a three-storey tower base. The Observatory site/precinct includes an 18-metre dish which was used in conjunction with the main dish until the 1980s and has now been decommissioned. The Observatory also has a Visitor Centre and associated support buildings, including workshops, storage buildings and support labs.
Discrete Heritage place identification number for each place
- Place ID 106345 – Place File No: 1/07/255/011
- Ref: Australian Heritage Database (environment.gov.au)
Summary Statement of Significance
The Parkes Observatory is a radio astronomy observatory located on Wiradjuri Country near Parkes, NSW. The Observatory is centred on the site's 64-metre radio astronomy telescope, constructed by the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and opened in 1961. Parkes Observatory is nationally significant in the course of Australian cultural history for its importance to the history of Australian astronomy, and for its association with the Apollo 11 moon landing.
Astronomy is significant in Australia's cultural history for the way it has helped shape Australians' understanding of the world around them, with the night sky a source of both practical and philosophical information about the universe. As people have studied the sky over history, the boundaries of the universe we live in have expanded, leading to philosophical questions about our position within an environment on such a large scale. Similarly, discoveries such as explaining the age of the universe have expanded our ability to look millions of years into the past and help shape our understanding of the future. As such, Australians and humanity as a whole have a sense of their place in space and time which shapes cultural processes, for example challenging religious understandings of the universe or the importance we place on maintaining a liveable environment on Earth.
Parkes Observatory demonstrates the importance of this cultural process in Australian history. The decision to construct the telescope is a recognition of the importance of astronomy to Australian science, in an era where Australia was an international leader in the ground-breaking field of radio astronomy. In the latter half of the twentieth century, Australian scientists built on the skills and knowledge developed during World War II to undertake leading astronomical research. Parkes Observatory's radio telescope contributed to scientific discoveries with importance to Australians' lives, such as establishing the Big Bang Theory and Einstein's General Theory of Relativity. Parkes Observatory's importance in the history of Australian astronomy is complemented by its function as an operating radio observatory which has continued to be adapted, allowing it to remain at the leading edge of the field over time.
The Parkes Observatory is also nationally significant for the key role it played in the 1969 Apollo 11 moon landings. Part of a network of space tracking stations, Parkes Observatory was the source of footage for the majority of the international television broadcast of Neil Armstrong and Buzz Aldrin's walk on the lunar surface. This event was important to Australians for the way it demonstrated the peak of humanity's spirit of discovery as well as of scientific and engineering achievement, something experienced by Australians as they collectively shared in the moment through watching the live footage of the moon landing.
The Parkes Observatory is also a nationally significant technical achievement as a pioneering piece of scientific equipment that was constructed with innovative scientific and engineering methods. The Observatory's original radio telescope was one of the first large single-dish radio telescopes constructed in the world, and the large size of its dish on a tower base was a rare early achievement for its time. The functional technologies that allow the dish to operate, including its mounting, guidance mechanism and receivers, were novel solutions which made possible CSIRO's goal of delivering a large dish telescope that could function as a world-leading piece of scientific equipment. Ongoing upgrades to the dish have built on this legacy of technical accomplishment, allowing it to continue to operate as a functioning example of scientific and engineering achievement to the present day.
These outstanding national heritage values are expressed through the Parkes Observatory site, in particular the nature of the original radio telescope as a large, single-dish telescope on its tower base.
Official Values
Criterion A – Events/Processes
a. – The place has outstanding heritage value to the nation because of the place’s importance in the course, or pattern. Of Australia’s natural or cultural history
The Parkes Observatory is a place of outstanding value to the nation for its importance in the history of Australian astronomy.
Astronomy is an important cultural process in Australian history due to the way Australians have used astronomical research to understand the world around us. From the earliest times, humanity's relationship with the night sky and space has given it a central role in our cultural heritage. People have sought to understand the world around them by interpreting the cosmos, and in doing so have grappled with both scientific and philosophical questions. The discipline of radio astronomy is a key element of this process. By studying space at radio frequencies that were previously inaccessible, radio astronomy in the twentieth century greatly expanded Australians' understanding of the universe. Its discoveries contributed to explaining the origin and the shape of the expanding universe. Radio astronomy also contributed to the creation of technologies like WiFi and GPS.
This importance of astronomy in the course and pattern of Australian history is demonstrated by Parkes Observatory. Australia was an international leader in the ground-breaking field of radio astronomy research in the post-World War II period, as wartime technological advances in radiophysics combined with an expansion in Australian scientific research. Parkes Observatory was central to this period of Australian astronomy.
The idea of the Parkes radio telescope, Murriyang was conceived of by staff of the Radiophysics Division of the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in the 1950s. Australian physicists such as Dr Taffy Bowen applied their wartime radiophysics knowledge to a new research-focused peacetime context. As the field of radio astronomy rapidly expanded, the decision to construct the telescope at Parkes was a reflection of the importance of astronomy in Australia's scientific and cultural landscape.
The design of Parkes was led by Australian physicists with expert input from around the world. Innovative engineering and technological solutions allowed CSIRO to construct the largest single dish telescope dedicated to astronomy in the Southern hemisphere. The importance of the Observatory in Australian astronomy is also reflected in the way it has provided observations which have been key to discoveries of importance on a global scale, which shape our understanding of the world around us and therefore are relevant to Australians' lives. For example, it has been used to undertake all-sky surveys and to identify celestial objects like quasars and pulsars which were, respectively, key pieces of evidence in establishing the Big Bang theory and testing Einstein's General Theory of Relativity.
Parkes Observatory was a model for a number of subsequent similar single-dish installations both in Australia and overseas, due to the success of its pioneering design. In addition, it laid the groundwork for Australia's ongoing involvement in the field of radio astronomy, which continues to the present day. Updates to the Observatory's technology have allowed the Observatory to remain significant in the practice of Australian astronomy, while other radio astronomy observatories in Australia build on Parkes' legacy.
The Parkes Observatory also has outstanding heritage value to the nation for its association with the Apollo 11 moon landing in 1969.
The Parkes Observatory played an important role in the television broadcast of the moon landing, which was watched by approximately 530 million people across the world. Australians were part of the global community for whom this event was an epochal moment, which represented humanity's spirit of discovery and demonstrated the peak of mid-twentieth century scientific and engineering endeavour.
Neil Armstrong and Buzz Aldrin stepped on the moon on 21 July 1969 (AEST), and soon after their first steps, NASA switched to the Parkes Observatory signal to be the source of the majority of the two and a half hours of moonwalk footage that was broadcast to the world. The television broadcast of this is particularly significant to Australians because of its prominent role in community memory as a defining achievement of the twentieth century. A number of tracking stations were involved in the tracking and broadcast of the Apollo 11 mission; as the source of broadcast signals for the majority of the moonwalk, Parkes Observatory has a strong association with the moon landing because of the key role it played in the memorable television experience. This association was particularly strengthened with the release of "The Dish" in 2001, a film loosely based on the role of the Parkes Observatory in the moon landing.
The features that express these nationally important heritage values are the original main telescope at the Parkes Observatory, most significantly its form as a large single-dish radio telescope on its tower base. Functional upgrades that have occurred to the telescope since its original construction are consistent with its heritage significance. These features are important to demonstrating the significance of the Observatory in the history of Australian astronomy and its association with the Apollo 11 moon landing as the receiving dish for broadcast signals.
Criterion F – Creative or Technical Achievement
f. The place has outstanding heritage value to the nation because of the place’s importance in demonstrating a high degree of creative or technical achievement at a particular period.
The Parkes Observatory is a place of outstanding value to the nation for its ability to demonstrate a high degree of technical achievement. The design and construction of the 64-metre main radio telescope at Parkes Observatory was an innovative engineering and scientific milestone in the post-war era, and ongoing adaptations and updates have allowed it to maintain this legacy as a leading scientific instrument.
The Parkes radio telescope, Murriyang was the first large single-dish telescope in Australia, as well as being one of the first large radio telescopes in the world. Its initial design and construction from 1954 to 1961 involved the invention of new technologies and techniques by CSIRO staff and engineers. The alt-azimuth mounting of the telescope allowed for a larger dish size to be constructed in an era where large radio astronomy dishes were pioneering technology. The creation of a novel guidance mechanism for the telescope dish to adjust this mounting allowed it to be controlled to a higher accuracy than other single-dish telescopes of the time, while the receivers built for the telescope allowed it to detect radiowaves at a wider range of frequencies and with more sensitivity than other telescopes. The Parkes telescope was used as a guide for other radio telescopes in Australia and internationally, with Parkes a model for large single-dish telescopes used in both radio astronomy and spacecraft tracking.
The technical achievements of the Observatory had impact on the field of astronomy in Australia as well as overseas. The high quality and number of scientific discoveries associated with the site are made possible by the scientific and technical design excellence of the telescope.
Elements of the Parkes telescope which made it a technical achievement at the time of its construction have been updated in a way which is consistent with the continuity of its heritage significance as new technologies develop. For example, in the decades since its construction new receivers and mesh surfacing have been installed. Such updates reflect the way in which the innovative original design and construction positioned the Observatory to be able to work from a basis of technical excellence when undertaking necessary updates that allow it to remain at the forefront of its field.
These values are expressed through the original main telescope at the Parkes Observatory, most significantly its form as a large single-dish radio telescope on its tower base, with the existence of receivers and a guidance system to control the telescope. Functional upgrades that have occurred to the telescope since its original construction are consistent with its heritage significance. These features are important to demonstrating Parkes Observatory's nature as a technical and engineering achievement which functions as a world-leading piece of scientific equipment.
History
Astronomy in Australian History
The study of the night sky has been a significant part of Australia's cultural history since human occupation began, over 60,000 years ago. Astronomical science draws on the fields of mathematics, physics and chemistry to study celestial objects and phenomena, leading to discoveries about not just distant objects in space, but also the nature of Earth. These discoveries intersect with cultural beliefs and perspectives on the natural world which help Australians to give meaning to the universe around us.
Knowledge of the sky was and is deeply embedded within Aboriginal and Torres Strait Islander culture and tradition. Indigenous Australians have used the sky as a "scientific textbook, a map, a law book, and a canvas on which complete layers of knowledge are interwoven, linked and recorded for future generations" for thousands of years (University of Melbourne). Songlines, which function as oral maps of the landscape, can have mirroring paths in the sky, while planets and stars have been used by Indigenous Australians as with societies all over the world to measure time and seasons, and navigate across the country for purposes such as annual travel cycles and trade. For example, the Wiradjuri people, whose land centres on Central New South Wales, tell the story of ancestral pursuit of an emu, with both figures represented in the sky as constellations (Leaman and Hamacher, p 226). These constellations move around the South Celestial Pole, drawing a connection with the pursuit of the emu in the ceremony. The emu constellation is further used as a food and season tracking tool. The Celestial Emu or Gugurmin (Wiradjuri) constellation is observed by many Aboriginal nations all year round (Norris, p 16). The appearance of Gugurmin early in the year indicates the start of emu breeding season. Later into the year, the constellation appears horizontal in the sky, indicating that the emus are nesting and eggs are available for gathering. Towards the end of the year, Gugurmin's head dips below the horizon, indicating egg season is over. The use of astronomical knowledge by Australia's First Nations people exemplifies the ways in which astronomy becomes embedded into culture.
With the arrival of European settlers, astronomy was central to wayfinding and understanding the Australian continent. The constellations of the Southern Hemisphere gave a new perspective to European science. In the early eighteenth and nineteenth centuries "Australia served merely as a convenient fixed platform for temporary observatories established under direct British aegis" (Home, p xi). However, as the nineteenth century progressed, Australian scientists began to establish their own research bases. For example, the construction of the Sydney Observatory in 1858, which was used for "shipping, navigation, meteorology and timekeeping as well as to the study of the stars seen from the Southern Hemisphere" (Museum of Applied Arts and Sciences). The Melbourne Observatory, constructed between 1861 and 1863, was one of only four nineteenth century observatories in the Southern Hemisphere, and provided meteorological data for Victoria as well as contributed to the global project to observe the Transit of Venus in 1874 (Department of the Environment and Energy, 2018).
In the early twentieth century, astronomy continued to play an important role in Australian science. In 1905 the Australian astronomer Geoffrey Duffield identified the value of an Australian solar observatory, which due to its location could contribute to the continual worldwide monitoring of solar activity (Bhathal, Sutherland and Butcher, p 4). The Commonwealth government was persuaded by the proposal, and after the conclusion of World War I work commenced at Mt Stromlo in the Australian Capital Territory, with the Commonwealth Solar Observatory completed in 1924 (Department of the Environment and Energy, 2004).
Post-World War II Australian Astronomy
In the late 1940s and early 1950s, Australia was recovering from years of economic depression and war. Recovery from World War II was a trigger for political, economic, social and cultural changes which saw Australia cultivate new areas of expertise and helped shape a new Australian identity. Australian science changed and expanded, with scientific and technological development that occurred during the war being applied in a peacetime context. Prior to the war, agricultural sciences had been the focus of Australia's scientific community, and educational limitations meant many Australian scientists moved overseas to research. During the war years Australian scientists' principal achievement was "the part they played in the remarkable transformation of Australia's technical and industrial capacity" (Home, p 220). Australia's first PhDs were awarded in 1948, helping to keep Australian talent in the country rather than forcing them to go overseas to undertake higher studies and research (Group of Eight, p 9). After the war the physical sciences had increased prominence in the Australian scientific landscape, as "the changes the war had brought about in the Australian economy rendered permanent the shift that had taken place in the balance of Australian scientific power" (Home, p 221).
The Council of Scientific and Industrial Research (CSIR) expanded expenditure six times by the end of the 1940, and "by the end of the war politicians of all persuasions were insisting that expenditure on CSIR should be increased, as it was one of the best investments the nation could make" (Schedvin, pp 282, 284). In 1949 the CSIR was enlarged and reconstituted to form the Commonwealth Scientific and Industrial Research Organisation (CSIRO). World War II meant that "a new base level of scientific expertise was established in the nation [and] the beginnings of a modern industrial society had been laid" (Home, p 222).
Astronomy was one of the key disciplines of increasing prominence in Australian science at this time. This was primarily due to Australia's leadership in the new field of radio astronomy – the study of space at radio frequencies. Radio astronomy had only started to develop as a field a few decades earlier – in the early 1930s the American physicist Karl Jansky identified a source of radio signals outside the solar system (Robertson, p 10). With the development of RADAR in World War II, improvements in electronics allowed scientists to better receive and analyse the radio signals which had been discovered in the 1930s.
Unlike optical astronomy, which allows scientists to observe bodies in space that emit visible light, radio astronomy allows astronomers to see objects which emit "invisible light". Consequently, the birth of the field of radio astronomy greatly expanded humanity's knowledge of the universe, leading to the discovery of new types of objects in space, and more information about familiar objects. The discoveries of radio astronomy have provided evidence which tests or supports theories such as the Big Bang and Einstein's Theory of General Relativity. Radio astronomers have discovered the afterglow of the Big Bang, mapping the shape of galaxies, and used data to produce images of space as it would look outside the visible wavelengths of light. The advancements from radio astronomy have also had consequences on a practical level, with wireless technology developed as part of radio astronomy key to the invention of WiFi by the CSIRO (CSIRO, 2015). As described by the astronomical historian Owen Gingerich, "even if radio astronomy has not so much destroyed our older astronomical viewpoint, it has enormously enlarged and enriched it. It is like that magical moment in the old Cinerama, when the curtains suddenly opened still further, unveiling the grandeur of the wide screen" (Robertson, p 220). Radio astronomy was therefore fundamental to the advancements in astronomy and our understanding of the universe in the latter half of the twentieth century.
Australia's twentieth century leadership in radio astronomy came out of its close relationship with the UK during the war. Along with Australia, the UK was a pioneer in radio astronomy, and a strong community of radio physicists developed in Australia in the 1930s with links to the British scientific community. While many other areas of science and industrial research during the war focused on production for the war effort, radiophysics maintained a strong research focus due to the ground-breaking nature of the field, which was carried through to the post-war period (Home, p 248). During World War II the UK shared its radar secrets with the Commonwealth to nurture this research (Home, p 308). After the war, the Australian scientists continued their research focus, motivated by their experience of working at the leading edge of radiophysics.
As a result, Australia, along with the UK, became a centre for radio astronomy research in the latter half of the twentieth century. Australian physicists salvaged large amounts of radar equipment from the US Pacific Fleet in Sydney at the end of the war, which would have otherwise been destroyed, and used these materials to invent new experimental scientific equipment (Robertson, p 57). Physicists based out of the CSIRO Radiophysics lab built smaller radio instruments dedicated to detailed research in particular areas of astronomy, such a focus on solar work (Robertson, p 75). By innovating with engineering and exploring different aspects of radio astronomy, the adaptability of Australian scientists allowed them to position themselves at the forefront of the field internationally, and they made a number of discoveries with these early instruments.
Australia's position as a world leader in a field of emerging scientific research was a strong contributor to the post-war narrative of Australia that the nation was seeking to develop. In the post-war period CSIRO was transitioning into the field of "high technology and big science", and at the end of the war "radiophysics was CSIR's glamour division" (Schedvin, p 232; Home, p 310). Involvement in the field of radio astronomy was one of CSIRO's leading exemplars of a new, more ambitious Australian identity being communicated to the nation and the world.
The Parkes Observatory
By the late 1940s and early 1950s, this early era of improvised radio astronomy was giving way to a need for more significant investment in the field, with larger and more permanent constructions to ensure continuing advancement. At the end of the 1940s, the UK commenced plans to build a 77 metre (250 ft) radio telescope, known as the Lovell Telescope after its creator, Bernard Lovell. This proposal for the largest steerable radio telescope in the world, to be built at Jodrell Bank in the North West of England, was watched with interest by Australian scientists. The Chief of the CSIRO Division of Radiophysics, Dr EG Bowen, proposed that Australia should build an equivalent telescope (Goddard and Milne, p 7). Bowen had played an instrumental role in the development of radar and its use during the war in Britain, and with the support of scientific colleagues, met with potential supporters both in Australia and overseas to seek support for the idea. Bowen's perseverance paid off, and in the 1950s the telescope received initial funding from the Carnegie and Rockefeller Foundations, which was added to by the Australian government. This funding provided for the construction of the Parkes Observatory.
With funding secure, planning commenced for the construction of the telescope for the Observatory. The town of Parkes was chosen as the location due to its distance from the radio interference of Sydney, suitability of flat ground, and support of the local authorities (Goddard and Milne, p 10). Parkes is situated on the land of the Wiradjuri, who live on the plains of central New South Wales. The Wiradjuri are the largest Indigenous group in New South Wales, and the Wiradjuri lands were known as the land of the three rivers, the Murrumbidgee, Gulari (Lachlan) and Womboy (Macquarie). These rivers provided sources of food to the local people, as did the surrounding environment. Wiradjuri land was colonised by Europeans relatively early in European settlement of Australia, with the first Europeans arriving in the region in 1813. There was a rapid influx of settlers which led to violent clashes between the Wiradjuri and the British known as the Bathurst War, based around the town of Bathurst east of Parkes. The fertile plains west of the Blue Mountains were progressive occupied by European settlers over the first half of the nineteenth century, dispossessing the Wiradjuri of control of their traditional lands, where many still live today. Parkes itself was founded under the name Currajong in 1853, and the land on which the Parkes Observatory was built was part of a property owned by Australia James Helm, a farmer whose name came from the fact that he was born on Federation Day, 1 January 1901 (Kerr, p 10).
Construction started in 1959. Due to the novelty of the field of radio astronomy, the scientists and engineers building the telescope had few examples to follow. The London engineering firm Freeman Fox and Partners was contracted for the design study of the telescope; the partner responsible for the telescope had assisted Sir Ralph Freeman on the design of the Sydney Harbour Bridge. In addition to this, the British engineer Sir Barnes Wallis, who had invented the bouncing bomb in World War II and was Chief Engineer of the Vickers firm, was consulted. It was Vickers who warned that "the design of a giant radio telescope is a venture into the unknown" (CSIRO, 2016b).
Various designs were proposed, some similar to the Lovell Telescope, suspended on two towers, others embedded in the ground. Ultimately, the single tower construction was decided upon, which allowed an even distribution of stress, unlike a two tower system (Robertson, p 147). Functional aspects of the telescope's operation such as the mounting and guidance system also needed to be designed. Problem solving by scientists and engineers resulted in unique solutions fitted to the needs of the size and structure of the telescope. Deflection of the telescope's structure was addressed by using incompressible columns, while changes to the dish's parabolic shape were automatically compensated for (CSIRO, 2016b). The mounting of the telescope manages the way in which it is turned and point in the sky. An "alt-azimuth" mount allowed for movement vertically and horizontally, while an "equatorial" mount is designed to be pointed at the celestial pole, aligning it with the Earth's rotational axis and making it easier to track stars' motion across the sky. An alt-azimuth mount was favoured for Parkes because of its structural simplicity – an equatorial mount would have required a smaller dish (Goddard and Milne, p 15). However, an alt-azimuth mount needed a complex computing system for guidance, and most observatories used at the time used equatorial mounts. Since the knowledge of how to create such a guidance system was not yet widespread post-war, those working on the Parkes project combined their engineering experience with innovation to create a servo mechanism (an automatic device which corrected the action of other mechanisms) and "master equatorial" guidance system that addressed these concerns (Goddard and Mile, pp 15, 16). These inventions allowed Parkes Observatory to be constructed with an alt-azimuth mount. CSIRO also installed leading-edge receivers, which collect, focus and record radio signals received by the telescope.
The 64-metre diameter telescope was officially opened on 31 October 1961 by the Governor-General, Viscount De L'Isle (CSIRO, 2016b). With the successful performance of tests, the telescope was handed over to CSIRO in March 1962 (Goddard and Milne, p 7). The successful design of the Parkes telescope was the inspiration for other radio telescopes in Australia and overseas. Freeman, Fox and Partners designed a 45-metre version of the dish for the National Research Council of Canada, and the Parkes telescope also served as a guide for 64-metre antennas for the NASA Deep Space Network in the Jet Propulsion laboratory in California, commenced in 1962, which used the master-equatorial and servo mechanisms created for Parkes (Goddard and Milne, p 17).
Despite its successful commissioning, the telescope had design problems which had to be rectified over a period of time. In 1969 the tower base needed to be reinforced to handle the weight of the dish, which was progressively damaging the structure of the building (Robertson, p 269). Nevertheless, the telescope made a number of important contributions to scientific research. Scientists at Parkes undertook "all-sky surveys" where they surveyed the skies at certain frequencies and catalogued radio sources. The all-sky surveys revealed thousands of radio sources. In 1962 a survey supplied data on one radio source, 3C 273, which allowed it to be the first identified "quasar" (CSIRO, 2019d). Quasars, short for quasi-stellar radio sources, are some of the most distant objects from Earth, and allow for study of distant galaxies and reveal information about the age of the universe. Quasars produce radio signals which appear to be coming from a star, but are much brighter than the emissions from such a star should be. The data retrieved from the survey of 3C 273 allowed scientists to discover that the reason the radio signals appeared anomalous was due to the huge distances away from earth from which the signals travelled. This discovery led to a better understanding of the size of the universe, as objects so far away must be of a much greater age, and therefore contributed as a piece of evidence towards the acceptance of the Big Bang Theory, which was still unresolved at that time (Carnegie Institution for Science).
The Parkes telescope was also the instrument used to discover two-thirds of the 1,800 known pulsars – rotating neutron stars which emit pulses of radiation as they rotate (CSIRO, 2017b). Most of these discoveries have been made since 1997 (CSIRO, 2017c). Observation of the radio waves of pulsars allows scientists to determine information such as their distance and age, and many pulsars are found in binary systems, paired with other stars and planets. Discovery of pulsars often leads to the discovery of new planets and stars, as well as other celestial objects. For example, a pulsar discovered using the Arecibo antenna in Puerto Rico provided the first evidence of the existence of gravitational waves, agreeing with Einstein's General Theory of Relativity and leading to the discoverers receiving the Nobel Prize for Physics in 1993. The only discovered binary system of two pulsars was found using the Parkes telescope (CSIRO, 2016b).
Parkes is the largest single-dish telescope in the southern hemisphere dedicated to astronomy (CSIRO, 2016b). The breadth and scale of discoveries at the telescope resulted in it being an Australian- and world-leader in the field of radio astronomy. Over time, upgrades to the telescope have allowed it to continue to undertake leading scientific research. In the 1970s improvements were made by resurfacing the dish to improve accuracy, replacing original mesh with perforated aluminium, as well as installing new receivers with higher sensitivity, and introducing computers to process data (Robertson, p 292). Upgrades continue to be made, such as the installation of a 13-beam multibeam receiver in 1997, which provided for even greater efficiency in large-scale radio surveys (CSIRO, 2016b).
Parkes Observatory is also used in collaboration with other observatories to undertake coordinated research. CSIRO's radio astronomy observatories are collectively known as the "Australian Telescope National Facility", comprising the Parkes Observatory, the Australia Telescope Compact Array near Narrabri, NSW, and the Mopra telescope, near Coonabarabran. Construction was completed on a fourth telescope, the Australian Square Kilometre Array Pathfinder, in 2012, with its multiple antennas coming progressively online since that date (CSIRO, 2019b). The leading work undertaken at Parkes justified continued investment in the field of radio astronomy in Australia, and these later telescopes follow in the path laid by the Parkes Observatory, contributing to Australia's radio astronomy research.
Space Exploration in Australia
Although constructed as an astronomical telescope, the Parkes Observatory also played an important role in the era of space exploration.
Developments in rocketry during World War II led to many countries developing rocket and missile programs post-war. These rockets were the precursor to space rockets and satellites (Dougherty, p 10). Alongside these advancements in rocketry came improvements in astronomy research, and the space tracking capabilities needed to communicate with and monitor the new satellites and rockets being launched into space. The first images of Earth taken from space occurred in 1946, taken from a World War II era V2 rocket, while the first successful orbital launch was of the Soviet satellite Sputnik 1 in 1957. In the post-war environment, the competition of the US and USSR space programs were drivers of the expansion of science and technology around the world.
Australia played a key role in this space-race era, due to its scientific and technological capability, its close and friendly ties with the UK and US, and the suitability of its large areas of land in the southern hemisphere for building and testing space exploration infrastructure. The size of the UK meant it was not suitable for long-range missile testing, and Australia was an alternative for its new missile program (Dougherty, p 18). In Australia, the Long-Range Weapons Establishment at Woomera rocket range was the first foray into missile technology, commencing operations in 1947 (Dougherty, p 20). In this joint UK and Australian project, Australia shared "the development and maintenance costs of the rocket range in return for technology transfer, the employment of Australians within the facility and contracts to Australian industry" (Dougherty, p 19). Woomera progressed to become a site for the launch of satellites from rockets, with the first Australian satellite, the Weapons Research Establishment Satellite (WRESAT), launched in 1967 (Dougherty, p 26).
Concurrently, other countries were also developing their space capabilities, moving beyond simple rocketry to satellites and space exploration. The United States sought to launch a satellite in 1957-58, and requested to install satellite tracking facilities at Woomera (Dougherty, p 31). Tracking stations were needed at distributed longitudes around the planet to receive radio signals from spacecraft moving around the Earth. Australia was a particularly suitable option for such stations because the continent covers such a large area, and it was a politically stable country friendly to the US (Dougherty, pp 30, 31). In 1958 the United States founded the National Aeronautics and Space Administration (NASA), and already-existing tracking and lunar probe programs were transferred to NASA's control. The next form of exploration to come was planetary exploration missions, and in 1960 a formal agreement was made between the Australian and US governments to cooperate in tracking these missions (Dougherty, p 32). The Parkes Observatory was the first telescope to be used in joint spacecraft tracking projects with NASA under this agreement, when in 1962 it was used to receive signals from the unmanned Mariner 2 spacecraft (CSIRO, 2017a).
Parkes Observatory was of particular interest to NASA in the tracking of spacecraft because its large size made it capable of greater sensitivity and reliability than the smaller antenna recently built at Woomera (Robertson, p 259). It had also cost Australia less to build than the Woomera dish had cost NASA, despite being more than double the size (Robertson, p 256). For these reasons, NASA was interested in drawing on the Observatory both as part of their network and as a guide for construction of their own stations. As such, in the early 1960s the Parkes Observatory played a key role in the developing relationship between NASA and Australia, with an agreement that NASA could enlist Parkes as a tracking station when needed during missions. NASA was also provided with copies of the technical specifications for the dish, which were then used as a prototype for second generation Deep Space Network dishes such as that built in 1964 at Tidbinbilla, ACT (Robertson, p 259). The scientists working at the Observatory saw that NASA's use of the Lovell Telescope in the United Kingdom had led to increased public and government support for the site, and recognised the value of similar outcomes for Parkes (Robertson, p 262).
Starting from the initial 1960 agreement to integrate the Parkes radio telescope, Murriyang into the NASA tracking network, Australia became the country with the largest number of tracking stations in the world outside the US, a fact that only increased in significance when President John F Kennedy announced in 1961 America's intention to put humans on the moon before the end of the decade with the Apollo program. The three NASA networks were the Deep Space Network, which communicated with interplanetary spacecraft, the Manned Space Flight Network, to communicate with crewed spaceflight, and the Space Tracking and Data Acquisition Network, which tracked Earth-orbiting satellites (Dougherty, p 32). The Carnarvon station in Western Australia was the first manned space flight station in the country, opened in 1964. The Honeysuckle Creek station near Canberra was added in 1967 to help support the new Apollo program, and the Tidbinbilla Tracking Station, also near Canberra, was established in 1965 as part of the Deep Space Network. These stations assisted each other in the tracking and support of crewed missions.
In 1966 NASA proposed to incorporate Parkes Observatory permanently into its global tracking network (Robertson, pp 263, 264). The Apollo program's lunar plans, and other research missions to further planets, needed larger dishes than those available in NASA's existing network. Increasing pressures on time allocations at Parkes for scientific research contributed to the NASA offer being turned down at this time, but in 1969 NASA again approached Parkes with an offer they could not resist, requesting their involvement in the Apollo 11 moon landing mission. NASA stated, "the provision of live TV from the lunar surface, is feasible only with the addition of support by large antennas of 64 m or greater diameter. In view of this, [NASA] would like to request [CSIRO's] consideration of the participation of the Parkes Facility in support of the Apollo lunar landing mission" (Robertson, p 264).
CSIRO accepted this request, and the Parkes Observatory played a key role in tracking spacecraft during the Apollo 11 mission, along with other Australian tracking stations. The Honeysuckle Creek and Parkes stations tracked the Lunar Module, which detached from the Command Module to land on the surface of the moon, while the Tidbinbilla station tracked the Command Module itself (Dougherty, p 41). Initially, the television broadcast of the moon landing was scheduled to come via US tracking stations, due to the scheduling of the moon walk in relation to the rotation of the Earth. However, in landing on the moon an excited Neil Armstrong overrode the planned 8 hour rest before their moon walk, and moved it forward by several hours (Robertson, p 268). This placed the US out of position, and the responsibility for broadcasting the moon walk fell to Australia. On the day of the moon landing, Parkes Observatory carefully tracked the moon. As the time for the moon walk arrived, the latitude of the Honeysuckle Creek station made it a suitable broadcast transmitter for the first steps on the moon. As the lunar module landed, both the Honeysuckle Creek station and Goldstone in California received vision of the moon landing. However, the Honeysuckle Creek footage was of a higher quality than that from Goldstone, so their video was used for the start of the moon walk. As the Earth rotated, about 6 minutes later Parkes Observatory came into range to receive video from the Lunar Module, and at that point the quality of their footage was such that Houston switched to use the Parkes Observatory video for the rest of the broadcast. The remaining two and a half hours of Neil Armstrong and Buzz Aldrin's moon walk were broadcast to millions around the world, using the footage received by the Parkes telescope. Parkes' role in the Apollo 11 Moon Landing was fictionalised in the popular 2001 Australian film "The Dish".
The Honeysuckle Creek station was decommissioned in 1981, and its main dish moved to the tracking station at Tidbinbilla. Parkes Observatory continued to support space exploration missions in conjunction with the scientific study being undertaken on site. It played a role in the tracking of Apollo 13, as well as the Galileo probe to Jupiter, the Voyager exploration to Neptune and Uranus, the Giotto project to examine Halley's comet and the various Mars missions in early 2004 (CSIRO, 2016b). Recently, it helped track the Curiosity rover on Mars in 2012, as well as tracking the Voyager 2 probe in 2018 as it became the second human-made craft ever to enter interstellar space (Australian Broadcasting Corporation, 2018).
Condition and Integrity
The Parkes Observatory is comprised of the 64-metre functioning radio telescope managed by the CSIRO, and its support buildings. As such, the telescope is in good condition and well-maintained by CSIRO. Over time, there have been updates and alterations to the telescope since its completion in 1961 to facilitate its ability to continue to perform at the forefront of radio astronomy, for example replacing the original dish surface with more sensitive material which allows for greater scientific precision. These alterations support the demonstration of the history of the site.
The condition of the Parkes Observatory supports the significance of its heritage values. It remains as a functioning radio telescope, which allows it to demonstrate the potential National Heritage values of the site.