SKA history book

The Square Kilometre Array (SKA) is a grand vision project to build the most sensitive radio telescope in the world. This open access book tells the story of its development – a story of transformational science, innovative engineering, and global collaboration. Its journey has been long and complex, reflecting the many issues faced in creating an affordable design, choosing a site, and developing a viable global organisation starting from a simple working group of far-sighted and persistent astronomers in 1993.

The book is based on the authors’ personal experience at the leading edge of the project over many years, as well as access to hitherto unpublished material from project archives, interviews, and presentations from many of the key players at a specially convened conference. The book is intended for an audience ranging from funding agencies and governments involved in major research infrastructures, to historians of science and professional researchers studying mega-projects, to the astronomy and physics communities in general and interested lay readers.

Below is a summary of the various sections of the book.

Foreword

Written by John Womersley, it provides his views on the challenges and excitement of the SKA project from his perspective as a leading scientist on the global stage and the ex-chair of the (funding) Agencies SKA Group and the SKA Organisation Board of Directors.   

Preface

This includes the motivations for writing the book, an overview of the SKA, the book plan, and acknowledgements.

Chapter 1. Introduction

This chapter sets the scene for the story of the formative years of the Square Kilometre Array by sketching the scientific, technical, funding, and cultural context for the project.

Chapter 2. Large Radio Telescopes and the Emergence of the SKA, 1957–1993

The SKA is the culmination of radio telescope design development in the decades prior to 1990. This chapter surveys the earlier telescopes and traces the origins of the ideas behind the SKA design including the people involved.

Chapter 3. Global Collaboration on Science and Technology, 1993–2006

Global SKA collaboration from concept to construction can be separated into four distinct phases. The “Grass-roots Phase” from 1993 to early 2006, led by astronomers and engineers began with the International Union of Radio Science Large Telescope Working Group (LTWG) and national design efforts working in conjunction. By 1999, growing global interest led to the formation of a Steering Committee to take the project forward. At the end of this Phase in early 2006, the funding agencies began to take an interest in the SKA collectively, heralding in the second phase of collaboration which lasted until the end of 2011, the “Transition Phase”  to an SKA legal entity and its recognition as a science mega-project. The Transition Phase led into the Pre-Construction Phase from 2011 to 2021, and subsequently the Construction Phase. In this chapter, we trace the evolution of the governance structures in the Grass-roots Phase, discuss the triggers that led to the changes, and summarise the activities of, and issues faced by, the governing entities in this period.

Chapter 4. Transition to a Science Mega-Project, 2006–2012

Following the Grass-roots Phase of global collaboration, the transition to an SKA legal entity and science mega-project (the Transition Phase) began. Three governance entities operated together in this period, (i) the International SKA Steering Committee, (ii) the funding agencies group, and (iii) the European Commission-funded SKA Preparatory Phase (PrepSKA) Board. In late 2011 this culminated in an Agreement amongst the funding agencies and governments to establish a company in the UK, the SKA Organisation, to govern the SKA in its Pre-Construction Phase. This lasted until January 2021 when an Inter-Governmental Organisation was formed to govern the construction and operation of the SKA Observatory. In this chapter, we describe the evolving governance in the Transition Phase, major activities, bumps along the road including the US decision in 2011 not to join the SKA, and the first year of the Pre-Construction Phase (2012). The first major decision of the new SKA Organisation, in mid-2012 – where the SKA telescope would be located – is described in Chapter 8.

Chapter 5. Evolution of the SKA Science Case

Here we describe the evolving SKA science case and how it informed the instrumental developments needed to build it. Itstarts with an outline of the scientific context in 1990, and the 10^th anniversary meeting for the Very Large Array in the USA. Significantly, in the early 1990s a formal international working group was established through URSI to develop the science case for an SKA. The dominant components of the science case include the evolution of the universe traced by neutral hydrogen, understanding the dark ages when the first stars are changing the state of the primordial hydrogen and the effect of the super massive black holes in the nuclei of galaxies.  We begin by discussing how the case for building an SKA was adapted to meet the aspirations of the different stakeholders in a global collaboration and conclude with a description of the scientific advances already being made by the SKA pathfinders.

Chapter 6. Innovation Meets Reality: The SKA Design

This chapter is an account of the creativity of a host of engineers and scientists to build a groundbreaking radio telescope with the performance needed to extract the scientific treasures buried in weak radio signals from the distant Universe, of which there were previously only hints. It covers the innovation history of the SKA, the management structures and processes implemented, and the individual technology innovations for the SKA including several potential mid-frequency dish structures, innovations in sampling the focal plane including phased array feeds, and aperture arrays at low- and mid-frequencies. Always moving forward, it describes the road from the ambition to overcome barriers and harness new technologies to the reality of thousands of difficult individual decisions made to successfully yield a realisable design in the available time. The global milieu in which this was done as an international project has set many precedents.

Chapter 7. Site Selection Story: 2002–2006—The Shortlist

The long, complex site selection process went through five distinct stages: (1) separate national initiatives in China and Australia to identify potential sites (1994–2002), (2) centrally coordinated activity to identify and characterise these and two other potential sites in Southern Africa and Argentina-Brazil (2000–2005), (3) the short-listing process and decision (2004–2006), (4) further characterisation of the two short-listed sites, and politicisation of the site competition (2007–2011), and (5) the final site selection process and decision (2009–2012). In this chapter, we describe and analyse the first three stages leading to a shortlist of two potential hosts, Australia and Southern Africa. Initially the International SKA Steering Committee (ISSC) aimed to select a single site in 2006 but after advice from the funding agencies, the goal of outright selection changed in mid-2005 to a shortlist of acceptable sites.

Chapter 8. Site Selection Story: 2006 -2012 – Decision

Here we continue the site selection story to its culmination in 2012, when the SKA governing body decided to locate the mid-frequency dish array in Southern Africa and the low-frequency array in Australia. This complex process is analysed in detail, as is the evaluation of the hosting proposals by expert consultants and an external SKA Site Advisory Committee. The final stage leading to the dual-site decision in 2012 engendered considerable tension in the project, not least due to the process having become highly political.

Chapter 9. SKA Headquarters: Another Two-Stage Site Selection Tussle

The International SKA Project Office (ISPO) was established in 2003 and hosted by ASTRON at its headquarters in The Netherlands. As the project’s global component expanded and substantial funding came into view in 2006–7, the International SKA Steering Committee (ISSC) held a competition in 2007 for the central office location. This led to the ISPO being moved in 2008 to the University of Manchester, renamed as the Program Development Office (SPDO). A fully fledged legal entity was required to manage the Preconstruction Phase, leading in 2011 to a second competition for a permanent headquarters site. Manchester was selected again. Here, we describe the issues surrounding these two contentious selection rounds.

Chapter 10. Industry Engagement

The protagonists of the SKA recognised early the need for industrial participation, reasoning that the instrument could neither be funded nor built without industrial economies of scale. Prior to 2009, industrial engagement took the form of lively, though uncoordinated, activities driven by member countries to stir industrial interest and encourage contributions to their national efforts. After 2009, the promise of imminent contracts fuelled closer engagement with large multinational companies interested in delivering the telescope and in potential spin-off technologies. Industry engagement grew more strategic, underpinned by industry consortia and international events promoting opportunities. Although the project ultimately elected to favour member country allocations, know-how developed around capability scouting and supply chain development up to 2012 led to a knowledge base that was foundational to other mega-science procurement. 

Chapter 11. Concluding Remarks

We conclude this account of the SKA’s formative years with an analysis of the major issues and challenges faced by the project against a backdrop of mega-projects in general, but especially science mega-projects. Others may benefit from seeing how this endeavour navigated its way to reality.

The book is available at link.springer.com