General Muhammed Ahmed Faris, a military aviator who became the first Syrian in space, fled to Turkey on Sunday after defecting from President Bashar al-Assad's regime, the Anatolia news agency reported.
Before crossing into Turkey, Faris visited the headquarters of the Free Syrian Army in Aleppo in a show of solidarity with rebel forces battling Assad's troops in Syria's biggest city, it said.
Anatolia said it was the fourth attempt to defect by Faris, who joined a Soviet crew on the orbiting space station Mir in 1987.