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Tribute to a Space Research Pioneer

On 27th February of this year, Ireland lost one of its Space research pioneers.

Professor Denis O’Sullivan joined DIAS as a PhD candidate in the early 1960’s. He went on to spend much of his career with DIAS, with occasional visiting positions in institutions across the globe.

Commenting on the passing of this eminent scholar Dr Eucharia Meehan said “Ireland has lost a true Space Research pioneer. He initiated Ireland’s participation in some of the most high profile space research experiments, from the early Apollo missions, to the International Space Station. He lead the way for Irish space researchers of today, and as a result DIAS continues to work on space projects at the forefront of exploration. We thank him for his tireless dedication to the institute and send our deepest condolences to his colleagues, friends and family.”

Details on these space experiments can be seen here:

DIAS: 50 Years as space research pioneers

Pictured L-R Professor Luke Drury, Professor Dieter Breitschwerdt, Professor Denis O’Sullivan, Carmel O’Sullivan and Vernon Jones from NASA in Adelaide Australia in 1991.

At his funeral in March, his friend and colleague Professor Emeritus Luke Drury was invited to speak on his scientific life.

The following will give you an insight into his accomplishments on that front.

Denis was a man of wide-ranging interests, but by profession and training he was a physicist who spent most of his life working in the Dublin Institute for Advanced Studies in the School of Cosmic Physics, and it is this aspect of his life that I have been asked to talk about today. I of course only joined the Institute in 1986, by which time Denis, together with his long-term co-worker Alex Thompson, were already well established as world-leading experts in the use of solid state nuclear rack detectors for cosmic ray studies.

Indeed Denis was one of the first in 1970, while on sabbatical in California in the laboratory of Buford Price, to apply this technique to samples of moon rock brought back from the famous Apollo 11 moon landing, whose 50th anniversary we have just celebrated. This subsequently resulted in the first Irish space  experiments, small stacks of nuclear track detectors which were flown to the moon and back on Apollo 16 and 17. Some of this material was later donated by Denis to the National Museum of Ireland.

Having made a significant improvement in the technique through their discovery of the registration temperature effect, Alex and Denis went on to become joint principal investigators of the first large-scale Irish space experiment, the Ultra-Heavy Cosmic Ray Experiment which was accepted for flight on NASA’s long duration exposure facility. This was a collaboration between the European Space Agency’s science and technology centre ESTEC in the Netherlands and DIAS as part of Ireland’s accession to the European Space Agency. Long duration turned out to be something of an understatement because the flight, originally meant to be one year long, was extended by the Challenger disaster to over six years! 

The analysis of this experiment has yielded the best available data on the abundance of actinide nuclei in the cosmic rays and is unlikely to be
surpassed in the foreseeable future. In later years Denis turned to questions of the radiation hazard for air crews and astronauts resulting from heavy cosmic rays and became one of the leading experts in this field with a number of EU-funded projects on the space station and in
aircraft (including the Irish Government jet). There are of course many other aspects to Denis’s research which I could mention, but I hope these highlights give some flavour of his work which was recognised by election as a member of the Royal Irish Academy in 2008.

In addition to his research work, Denis gave generously of his time and effort to community service. He was an active member of the Irish branch of the Institute of Physics and served on its committee for many years. He was one of the expert advisors assisting Paddy Cunningham in his role as chief science adviser to the Irish government. But perhaps his biggest contribution in this regard was to serve as the principal organiser of the 21st International Cosmic Ray Conference in 1991. This was at a time when the conference ran for two weeks and was a major logistical undertaking. It brought some 600 scientists and accompanying persons, including two Nobel prize winners, to Dublin for a programme of concentrated scientific discussions. Even now, nearly thirty years on, people remark to me how much they enjoyed the Dublin conference and much of the credit for that must go to Denis who used his natural charm and contacts to make the conference a memorable success (despite minor inconveniences like the first Gulf war and an attempted putsch in Moscow).

So to the first Irish man to examine a moon rock, to a pioneer of Irish space research, to the co-PI of the first experiment to collect a significant sample of cosmic ray actinides, to the organiser of one of the best cosmic ray conferences ever, to a friend and colleague, I echo Catullus in saying
“Ave atque Vale Denis”.”