Even if you had been allowed to kick the tires as the world's largest airplane was rolled out for the first time Wednesday, it might have taken you a while. Stratolaunch - which is designed to release rockets that will carry satellites into space -- has a 385-foot wingspan, features six engines used by the Boeing 747, stands 50 feet tall and can carry more than 500,000 pounds of payload.
And it has those 28 wheels. The twin-fuselage aircraft, the baby of Microsoft co-founder Paul Allen, was pulled out of its Mojave Air and Space Port hangar in California to begin fueling tests -- the first of many ground tests.
Jean Floyd, Stratolaunch's chief executive officer, said the goal is to have a launch demonstration as early as 2019.
"Over the coming weeks and months, we'll be actively conducting ground and flight line testing at the Mojave Air and Space Port," Floyd said in a statement. "This is a first-of-its-kind aircraft, so we're going to be diligent throughout testing and continue to prioritize the safety of our pilots, crew and staff."
While the Stratolaunch has the biggest wingspan, the Antonov An-225 is longer. When business mogul Howard Hughes' "Spruce Goose" lumbered into the air in 1947, the H-4 had an enormous wingspan of 320 feet.

Courtesy: CNN