Video - World’s biggest plane, Stratolaunch, may fly this year

The world’s biggest aircraft, the Stratolaunch, may be flying by the end of the year. This according to the man bankrolling the project, Microsoft co-founder Paul Allen. His big idea is for the giant plane to act as an air launch platform to make access to space easier, cheaper and more reliable.

Stratolaunch Systems, a subsidiary of Vulcan Aerospace, is building the enormous plane under a giant hangar at the Mojave Air and Space Port, in California, USA. The twin fuselage aircraft will be even larger than Howard Hughes' 1947 H4 Hercules, known as the 'Spruce Goose'. It'll also outsize the Antonov An-225 Soviet era cargo plane built for the Buran space shuttle, currently the world's biggest aircraft.

Although its first mission is that of an air launch platform, it can also be used to transport cargo, with a payload capacity of 500,000 lbs and a range of 1,300 miles (2,092km).

The fact that it will take off from a runway, rather than a logistically vulnerable fixed range, will enable it "to avoid hazards such as inclement weather, airborne traffic and heavy marine activity", states Vulcan. It claims the airborne launch platform will “significantly reduce the risk of costly delays or cancellations”. It will also avoid the huge fuel costs of launching from Earth. 

As the world's largest composite aircraft, it will also be lightweight for its massive size, with a gross weight of about 1,300,000 lbs (590,000kg). Scaled Composites said it had built 'roughly 200,000lbs of composite structure' for the craft.

The gargantuan plane has a wingspan of 385 ft (117m). If placed on an American football field, its wingtips would extend beyond the goalposts by 15 feet on each side. Composed of two Boeing 747 fuselages, they each measure 238 feet (72 m) long and are supported by 12 main landing gear wheels and two nose gear wheels, with a total of 28 wheels.

The ginormous aircraft will act as a mothership for rockets or satellites. Powered by six Boeing 747 Pratt & Whitney PW4056 engines, it will require a 12,000 ft runway to lift-off with a load attached to its underbelly.

Once at an altitude of 35,000 ft, it releases the rocket, which fires up its own engine and goes off into orbit. The pilot then returns the carrier aircraft back down to the ground.

Stratolaunch boasts that this system is set to make launching satellites into Low Earth Orbit a simple commute. Paul Allen says his dream is for it to drive progress in scientific research, making it possible to gather rich data at an affordable cost.

Vulcan expects it to be in commercial service by 2020.