航天科研人员留学被策反，回国后大量搜集核心要害情报给境外间谍，细节曝光：才到国外就被盯上，请吃烧烤增进感情

Group 1 - The article reveals a case of a Chinese aerospace researcher, Zhao Xuejun, who was recruited by foreign spies while studying abroad and later collected sensitive information for them upon returning to China [1][2] - Zhao was approached by a foreign national who flattered him and invited him to social gatherings, which led to a false sense of friendship and ultimately to his recruitment as a spy [1][2] - After returning to China, Zhao utilized his position at a research institute to gather critical aerospace intelligence and used specialized espionage equipment provided by foreign intelligence agencies, receiving hundreds of thousands of yuan in compensation [2] Group 2 - In June 2019, national security authorities took coercive measures against Zhao Xuejun, leading to his conviction for espionage [3] - In August 2022, Zhao was sentenced to seven years in prison for his actions related to espionage [3]