Microsoft co-founder unveils world's biggest plane

Paul Allen's Stratolaunch, which has a 117m wingspan, is designed to send satellites into orbit

The world's biggest plane, boasting a 117-metre wingspan, has been launched by the Microsoft co-founder Paul Allen.

The six-engine, dual-hulled Stratolaunch aircraft is designed to launch satellites into orbit. Launching the satellites on rockets while the Stratolaunch is in flight has the advantage of saving fuel comparing to sending them into orbit from a launchpad.