Updated

Stratolaunch has been under construction for four years, but the world's largest plane is finally ready to show itself.

The plane, designed by Stratolaunch Systems, has a wingspan larger than a football field and is designed to carry rockets into the stratosphere, before being fired into space.

The aircraft weighs approximately 500,000 pounds and can carry payloads up to 550,000 pounds, with a wingspan of 385 feet. By comparison, the largest wingspan of a plane that has flown at least one flight is Howard Hughes' Spruce Goose, which had a wingspan of 319 feet.

The plane, which has 28 wheels, was built in the Mojave desert inside a custom-built hangar. It's powered by six Boeing 747 engines and is getting ready for a test flight, according to Stratolaunch Systems CEO, Jean Floyd.

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"Over the coming weeks and months, we’ll be actively conducting ground and flightline testing at the Mojave Air and Space Port," Floyd wrote on the company's website. "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. Stratolaunch is on track to perform its first launch demonstration as early as 2019."

The company was launched by Microsoft co-founder Paul Allen in a race to be the preeminent company for aircraft that can launch objects into orbit. Recognizing the achievement, Floyd added that more work is to be done and the company will have more to say.

"We have a lot of exciting activity ahead as we enter the testing process, and we look forward to sharing our progress during the coming months," Floyd wrote.