Los Angeles, Apr 14 (IANS): The world's largest airplane, developed by aerospace venture Stratolaunch, flew into the air for its first flight test on Saturday.

The gigantic, six-engined twin-fuselage megajet took off from Mojave Air and Space Port in California for the flight expected to last for a couple of hours, Xinhua reported, citing media reports.

Stratolaunch was founded by the late Microsoft co-founder Paul Allen in 2011 to develop the large carrier airplane as a flying launch pad for orbital-class rockets.

The aircraft has a world-record wingspan of 385 feet, and is 238 feet long. It is wider than any airplane on the planet. It weighs half a million pounds, according to a CNN report.

"A historic milestone for the #Stratolaunch team with this record setting aircraft taking flight! This is about going to the edge of space and beyond!" tweeted Thomas Zurbuchen, Associate Administrator for NASA Science Mission Directorate.

"I only wish the late @PaulGAllen could see this - his memory and impact lives on," he added.

Dozens of photographers, industry bloggers and aerospace enthusiasts gathered this week to catch a glimpse of the unique twin-fuselage plane.