Sitte was also entrusted with overseas research contracts, including space projects of the US Air Force. In 1959 he became deputy chief of the supervisory council of the research institute which was dominated by US, British and Canadians, and in this way he became familiar with the practical evaluation of the space research that was undertaken there. Because of his exposed position Sitte was subject to surveillance by the Israeli Intelligence Services. He drew suspicion through his visits to communist Czechoslovakia and because of two stays in the Soviet Union. More brazen still, from the start of the 1960s, was a series of conspiratorial meetings with a blacklisted (by Israeli intelligence) Czechoslovak diplomat in various cafés. Early in June 1960 Sitte asked his staff to produce written reports on their research projects.
