Penney was anxious to secure the services of Titterton, who had recently emigrated to Australia, as he had worked on the American Trinity and Crossroads tests. Menzies asked the vice chancellor of the Australian National University, Sir Douglas Copland, to release Titterton to work on Operation Hurricane. Cockcroft also wanted assistance from Leslie Martin, the Department of Defence's Science Advisor, who was also a professor of physics at the University of Melbourne, to work in the health physics area. The two men knew each other from their time at Cambridge University before the war. After some argument, Martin was accepted as an official observer, as was W. A. S. Butement, the Chief Scientist at the Department of Supply. The only other official observer was Solandt from Canada.