In the 1950's Jens-Goercke and Kleinwachter, guidance experts, established an avionics company in Bavaria. In 1960 Saenger, Pilz and Jens-Goercke founded INTRA (International Rakete) for the purpose of providing German expertise to Nasser in the production of indigenous Egyptian ballistic missiles. The effort eventually grew to 250 European engineers and 4,000 local employees. After the Egyptians successfully test-fired the first rocket in July 1962, Israeli intelligence chiefs were instructed to begin a covert campaign to force or frighten the German engineers away from the project . Two Israeli agents were arrested in Switzerland after they allegedly put pressure on the son and daughter of Jens-Goercke. The agents persuaded Heidi Goercke, 25, and her brother Hans, 21, to cross the frontier from Freiburg, Germany, into Switzerland and warned them that they must talk their father into coming home from Egypt or else he would face "serious" trouble . Eavesdropping on the conversation, forewarned Swiss detectives tossed the Israeli operatives into jail, but their message had gotten through. Jens-Goercke and the other foreign workers were driven away by Israeli death threats and diplomatic pressure by the end of 1963. The rockets produced had not been tested enough to be reliable, and the Egyptians abandoned them and turned to the Soviet Union.