In July 1949 the physicist Tom Kaiser, who has died aged 74, travelled from Oxford University to hand out pamphlets outside Australia House in London. The pamphlets were headed "Savage Acts of Australian Govermnent", and dealt with the decision by his homeland's labour administration to gaol striking coal miners.
Because he was on a Commonwealth Scientific and Research Organisation studentship - having just completed his doctorate - he refused to give his name to journalists. The reporters subsequently obtained it from Australia House officials, who had recognised him. A cable was sent to Australian Prime Minister Ben Chifly. "Atom Scientist in Red Attack on Chifly Government" blazoned a Sydney Sun special. "Laxity on Research Screening" headlined the Sydney Morning Herald.
Tom Kaiser was sacked from CSIRO for "grave indiscretion and breach of discipline". He was ordered to return to Australia and faced and enquiry. Thus was he unable to work in radio, or nuclear physics, in Australia.
Back in England, in 1950, he became an ICI Research Fellow at Manchester University's Jodrell Bank experimental station. There he began his work in space science, using radar to research the ionisation trails of meteors. In 1994, the then President of the Royal Astornomical Society, Professor Carole Jordan, presenting Kaiser with the society's Gold Medal, noted that the papers he had written three decades earlier remained the fundamental ones on the cross-section of the meteor's ionisation trail.
Kaiser was also (in the early 1950's) a member of the Communist Party of Great Britain. In 1952 he was a signatory to a cable to President Truman protesting against the death sentences imposed on Julius and Ethel Rosenberg who had been convivted of spying for the Soviet Union. A reply sent to him at Jodrell Bank alerted the director, Sir Bernard Lovell, to his CPGB membership. This, together with Jodrell Bank's reliance on US funding, led to a parting of the ways. Kaiser moved on to lecture in physics at Reading University.
In 1956 the space age was born, and Stalinism met it's great crisis with the Hungarian uprising. It was the year that Kaiser became a senior lecturer at Sheffield University. A nearby hill provided a radar base. From there, pulses were bounced of meteors. He was, as Jordan observed, "one of the first to realise that space technology would be important for the study of the upper atmosphere".
The confrontation between the Hungarian people and the Stalinist regime profoundly affected Kaiser. He left the CPGB.
Ten years after his arrival at Sheffield he became professor of space physics. He built up an internationally recognised group at the University, pioneered the role of Antarctica in space physics, and focused on rockets and satellites.
Kaiser was born and educated in Melbourne. In 1943 he graduated with a first in physics and radiophysics from the University of Melbourne. While working as a research officer in the Sydney Radiophysics Laborotory of the Council for Scientific and Industrial Research, he prepared his MSc. Then in 1947 came his CSIRO studentship, and research at Oxford University's Clarendon Laboratory. Together with his DPhil in 1949 came a Blue for lacrosse, which he continued to play and referee for many years.
The 1994 Royal Astronomical presentation was attended by many of his former students and colleagues, people eminent in their own fields, who wanted Tom to know how much they had been inspired by his teaching.
His resignation from the CPGB four decades ago did not weaken his socialism. He was a lifelong supporter of the Campaign for Nuclear Disarmament, and backed the Vietnam Solidarity Campaign in the 1960's.
He is survived by his wife, two sons and a daughter, and four grandsons.
Tom Kaiser, space physicist. May 2nd 1924, died July 2 1998.