After years of development in the desert north of Los Angeles, a gigantic, six-engined mega jet with the wingspan of an American football field flew Saturday morning for the first time.

“We finally did it,” said Stratolaunch Systems CEO Jean Floyd at a news conference from the hangar at Mojave Air & Space Port. “It was an emotional moment to watch this bird take flight.”

Stratolaunch, the company founded in 2011 by the late Microsoft co-founder Paul Allen, conducted the first test flight of the world’s largest plane.

Read more