Gaia/Hipparcos: project interviews

Naoteru Gouda (Osaka, 1960) did his early research in theoretical cosmology, on topics such as structure formation and galaxy clustering. Realising the importance of accurate astrometry in understanding the dynamics and evolution of stellar systems, he joined the National Astronomical Observatory of Japan in 1999. Since then, he has been leading the development of a mission for infrared astrometry, JASMINE. He joins me today to talk about its scientific objectives and technological progress.

Leslie Morrison (Aberdeen, 1938) was recruited to the Royal Greenwich Observatory by Astronomer Royal Richard Woolley in 1960. He worked in the Meridian Department until his retirement in 1998, contributing to studies of Earth rotation and the international time service. He was involved in the Carlsberg Automatic Meridian Circle, which used principles applied to Hipparcos as well as contributing to the Hipparcos Input Catalogue. He gives an insight into ground-based astrometry in the years before the move to space.

Anthony Brown (Leiden, 1969) was among the early users of the Hipparcos star catalogue data in the 1990s, stimulating his interest in space astrometry. As part of the working groups preparing for the Gaia data, he became chair of the Data Processing and Analysis Consortium (DPAC) in 2012. He joins me to describe how the enormous pan-European data processing task is structured and coordinated, and about some of the practical and sociological challenges facing the creation of this revolutionary star map.

Erik Høg (Lolland, Denmark, 1932) joins me for a second time. In an earlier conversation we talked about the period leading up to the adoption of Hipparcos in 1980. Today, we discuss the Hipparcos mission, from its acceptance in 1980 to its completion in 1997. We talk about his role in the mission development, and in the preparation for - and the analysis of - the data sent down from the satellite. We also talk about the addition of the Tycho experiment to the baseline mission, and his memories of the satellite launch in 1989.

Michel Bouffard (Niort, France, 1945) was the industrial project manager for the Hipparcos satellite at Matra Espace, Toulouse, during the mid-1980s. The company, later subsumed by EADS-Astrium and subsequently Airbus Industry, was appointed industrial prime contractor for the design and construction of the Hipparcos satellite. Here he talks about his experiences in managing the industrial side of this pioneering space mission, and his subsequent career and role in Gaia - within Astrium's science and Earth observation department.

Lennart Lindegren (Svalöv, Sweden, 1950) was a central figure in the development of the Hipparcos mission during the 1970s, he was one of the leaders of the three Hipparcos data analysis teams in the 1980s and 1990s, he was central to the formulation and development of Gaia in the 1990s and 2000s, and his work continues intensively today, focused on the analysis of the satellite data. We talk about what took him into space astrometry, and about his involvement in the preparation of Hipparcos.

Catherine Turon (Chelles, France, 1944) was a key figure in the development of space astrometry. In the 1970s, she played a key part in stimulating the wider scientific support for space astrometry. With the acceptance of Hipparcos by ESA in 1980, she set up and led the Hipparcos Input Catalogue Consortium, a 50-strong team of astronomers who worked for 8 years to construct the definitive star list that would drive the satellite operations and scientific programme. We look back at this complex, lengthy, and important activity.

Bill van Altena (Hayward, California, 1939), is Professor Emeritus at Yale University. As a key figure in determining star distances from the ground in the years before the launch of Hipparcos, and with a leading role in astrometry with the Hubble Space Telescope, he shares his unique perspective on how distance measurements were made from the ground, how the measurement of star distances has been transformed by the move to space, and how leaders of the field viewed the development of space astrometry.

Roger-Maurice Bonnet (France, 1937) was the European Space Agency's Director of Science between 1983–2001. He managed ESA's science programme for most of the duration of the Hipparcos mission, and during the selection of Gaia in 2000. We get his perspective on the early years of Hipparcos, the launch, the incipient disaster of the apogee boost motor failure, and the project's hard-won success. We hear his thoughts on Gaia's appearance following so quickly from Hipparcos, and the results that it is delivering today.

Erik Høg (Lolland, Denmark, 1932) spent most of his long scientific career at the Copenhagen University Observatory, Denmark, where he was involved in ground-based astrometry, before his focus moved to space astrometry. He played a key part in getting Hipparcos adopted in the 1970s–1980s, was one of its four scientific consortia leaders, and was central in the developments of Gaia. He talks here about the early part of his career: his contributions to ground-based instruments and to Hipparcos before its acceptance by ESA in 1980.