The double-bodied airplane is designed to serve as a mobile launch platform to carry rockets into low-Earth orbit.

World’s Largest Aircraft Passes First Engine Tests .

A colossal airplane with the world's largest wingspan - designed to serve as a launching platform for sending rockets into low-Earth orbit - has successfully completed its initial engine tests.

"In these initial tests, each of the six engines operated as expected," the spaceflight company Stratolaunch, which is led by Microsoft co-founder Paul Allen announced. The 747 turbofan engines were loaded with fuel, started one at a time and then allowed to idle at the Mojave Air and Space Port in California, US. The double-bodied airplane is designed to serve as a mobile launch platform to carry rockets into low-Earth orbit.

The Stratolaunch plane will make a runway-style takeoff, and when the aircraft reaches a cruising altitude of 11,000 meters, the rockets it is carrying will detach and then launch small satellites into low-Earth orbit. Stretching 118 metres across, the aircraft's wingspan is longer than a professional football field, the 'Live Science' reported. The vehicle weighs nearly 227,000 kilogrammes when empty and unfueled, but it is designed to carry another nearly 250,000 kilogrammes between the two fuselages.

"Over the next few months, we will continue to test the aircraft's engines at higher power levels and varying configurations, culminating to the start of taxi tests," Stratolaunch officials said. The company said that it already began testing the aircraft's flight control system as well as the electrical, pneumatic and fire-detection systems.