BRUSSELS, Aug 18 (Reuters) - Pilot Zara Rutherford, 19, took off on Wednesday at the start of a three-month bid to become the youngest woman to fly solo round the world. Rutherford departed from Kortrijk-Wevelgem Airport in western Belgium in her Shark ultralight, the world"s fastest microlight aircraft. The British-Belgian flyer hopes her voyage will encourage more girls and women to study and work in STEM (Science, Technology, Engineering and Mathematics), and spark girls" interest in aviation. "Growing up, I loved aviation and STEM - science, technology, engineering and mathematics, but I didn"t see many other women or girls doing that. I just always thought that was quite sad or discouraging," Rutherford told Reuters. "I"m hoping that I can encourage girls to go into this field." Rutherford is seeking to win the title from Shaesta Wais, who became the youngest woman to fly solo round the world at 30. The youngest male record holder, Mason Andrews, was 18 years old when he made the journey. Rutherford"s route will take about three months, with stops in 52 countries - including Greenland, China and Nicaragua - where she will stay with local families or in hotels. Born to parents who are both pilots, Rutherford will start university next year, with the dream of becoming an astronaut. "I love adventure, and I think space is probably the biggest adventure out there," she said. Reporting by Clement Rossignol; Writing by Kate Abnett Editing by John Chalmers and Giles Elgood Our Standards: The Thomson Reuters Trust Principles.