The world's largest airplane, weighing over 500,000 pounds, and with a wingspan of 385 feet, may be the most affordable and reliable way to carry satellites into space in the future, say engineers.
The Stratolaunch aircraft completed milestone land control tests last Sunday including a new runway taxi top-speed.
The massive plane with twin fuselages and six Pratt & Whitney turbofan engines is being developed by Microsoft co-founder Paul Allen's Seattle-based Stratolaunch Systems Corporation as a means of air-launching rockets into space. The Stratolaunch airplane would be able to bring rockets into Earth's stratosphere, which starts at about 33,000 feet above land at most middle latitudes.
Rocket launches from this altitude would allow for satellites to more easily enter and then start circling the globe at low-Earth orbit, or LEO.
Allen said on Twitter that the aircraft had reached a top taxi speed of 46 miles per hour. The Sunday test ''with all flight surfaces in place'' was conducted to ensure the craft's ability to steer and stop using its controls.
Though the first flight tests have not yet been announced for the Stratolaunch airplane, its maiden flight is expected to happen next year.
The plane is still being developed and has yet to fly, but it taxied last December out onto the runway at the Mojave Air & Space Port in Mojave, California. It hit a new top speed of 46 miles per hour in another test last Sunday. According to commentators if all goes according to plan, the plane will make its first test flight next year, though no date has been given as to when Stratolaunch might begin commercial operations.
According to experts, air launching rockets into space is not a new idea. The Pegasus XL rocket built by aerospace contractor Orbital ATK is launched from a modified Lockheed TriStar jetliner and similar projects are under development at Richard Branson's Virgin Group, NASA and Defense Advanced Research Projects Agency (DARPA).