Stratolaunch plane is seen flying above the California desert.

The world's largest airplane -- a Stratolaunch behemoth with two fuselages and six Boeing 747 engines -- made its first test flight on Saturday in California.

The mega jet carried out its maiden voyage over the Mojave desert.

It is designed to carry into space, and drop, a rocket that would in turn ignite to deploy satellites.

It is supposed to provide a more flexible way to deploy satellites than vertical takeoff rockets because this way all you need is a long runway for takeoff.

It was built by an engineering company called Scaled Composites.

The world's largest airplane, built by the late Paul Allen's company Stratolaunch Systems, makes its first test flight in Mojave.

The US company's gigantic aircraft`s wingspan is almost half that of an Airbus A380.

The strange aircraft, built by the legendary aeronautical engineering company Scaled Composites in the Mojave Desert, has two fuselages and is powered by six Boeing 747 engines.

It must theoretically be used to carry and drop at altitude a small rocket that will then light its engine, and will propel to space to place satellites in orbit.

The aircraft is so big its wing span is longer than a football field, or about 1.5 times that of an Airbus A380.

Specifically, the wing span is 117 meters; that of an Airbus A380 is just under 80.

The plane flew Saturday for about two and a half hours, Stratolaunch said. Until now, it had just carried out tests on the ground.

It hit a top speed of 304 kilometers per hour (189 mph) and reached an altitude of 17,000 feet, or 5,182 meters.

"What a fantastic first flight," said Jean Floyd, CEO of Stratolaunch.

"Today's flight furthers our mission to provide a flexible alternative to ground launched systems," he added.

Stratolaunch was financed by Paul Allen, a co-founder of Microsoft as a way to get into the market for launching small satellites.

But Allen died in October of last year so the future of the company is uncertain.

Agence France-Presse