The world's largest airplane, designed to transport hypersonic vehicles and facilitate easy access to space, has taken to the sky over California's Mojave desert.

Stratolaunch, the aerospace company founded by the late Seattle billionaire Paul Allen, put the world’s biggest airplane, nicknamed Roc, through its second flight test today, two years after the first flight.

“We are airborne!” the company announced on Twitter.

The giant twin-fuselage, six-engine plane has a world record wingspan of 385ft. In comparison, the wingspan of a typical jumbo jet is a mere 224ft. It also has a payload capacity of more than 500,000 pounds.