World's largest plane gets ready for its debut: Enormous Stratolaunch will send astronauts into orbit using a mini shuttle

 The largest plane ever to be built is creeping closer to completion, as the private space launch firm behind the craft - bankrolled by Microsoft co-founder Paul Allen - invited reporters to get their first look at the 'Stratolaunch'.

With a gargantuan wingspan of 385 feet (117 m) and six engines, the plane is taking a new approach in the private space race, by launching satellites and spacecraft into orbit from high altitude.

The craft will be larger than Howard Hughes' 1947 H-4 Hercules, known as the 'Spruce Goose,' and the enormous Antonov An-225, a Soviet-era cargo plane originally built to transport the Buran space shuttle that is currently the world's largest aircraft. 

 

  Stratolaunch Systems is part of Allen's privately owned Vulcan Aerospace, with the plane's launch coinciding with a surge of new businesses planning to sell Internet access, Earth imagery, climate data and other services from networks of hundreds of satellites in low-altitude orbits around Earth.

But the vision is different from what Elon Musk's SpaceX, Jeff Bezos' Blue Origin, Richard Branson's Virgin Galactic and other companies have for building commercial highways to space.

Musk's goal is to fly people to Mars. Bezos is developing low-cost, reusable rockets with the goal of moving energy-intensive, heavy industry off Earth. 

Branson is focused on space tourism and a small satellite launcher.

The advantage of the approach will be the ability to position the plane so satellites can be directly delivered into very precise orbits and do so quickly, without launch range scheduling issues and weather-related delays, Chuck Beames, who oversees Allen's space ventures, said.

Designed and built by Northrop Grumman Corp's Scaled Composites, the plane is similar in form and function to Scaled's aircraft built to ferry spaceships into the air and release them for independent rocket rides beyond the atmosphere, a service Richard Branson's Virgin Galactic intends to offer to paying passengers.