Story highlights Colossal aircraft brought out from its Mojave, California, hangar

It is designed to release rockets that will carry satellites into space

(CNN) 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.

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