BEIJING, Nov. 18 (Xinhua) -- Two astronauts who completed China's longest-ever manned space mission returned to Earth safely Friday afternoon.

Zhang Youxia, commander-in-chief of China's manned space program, announced that the Tiangong-2 and Shenzhou-11 manned flight mission, which lasted over a month, was a "complete success."

Zhang Gaoli, vice premier and a member of the Standing Committee of the Political Bureau of the Communist Party of China (CPC) Central Committee, delivered a congratulatory message from the CPC Central Committee, the State Council and the Central Military Commission at the command center of China's manned space program in Beijing.

The completion of the Tiangong-2 and Shenzhou-11 mission "marked a major breakthrough" in China's manned space program, according to the congratulatory message.

It said that under the leadership of the CPC Central Committee with Comrade Xi Jinping as the core, people of China's aerospace industry have implemented the innovation-driven development and civil-military integration strategies.

Their efforts to forge ahead and overcome challenges, as well as their collaboration and sacrifice, demonstrate confidence in the path, theory, system and culture of socialism with Chinese characteristics, it said.