Chinese astronaut delivers lecture from space
20 June 2013 Last updated at 18:25 BST
China's second female astronaut, Wang Yaping, has delivered the country's first-ever video lecture from space.
Speaking to students via live video, Ms Wang used spinning tops, a ball, water and a fellow astronaut to explain physics in zero-gravity.
She was speaking from the Tiangong-1 space laboratory, where the Shenzhou spacecraft is currently docked.
John Sudworth reports.