Paul Allen’s Stratolaunch picks up the pace in runway tests of world’s biggest airplane

Stratolaunch’s twin-fuselage airplane undergoes taxi tests at California’s Mojave Air and Space Port. Note the size of the pickup truck that’s traling the plane. (Stratolaunch Photo)

Stratolaunch Systems, the space launch venture backed by Microsoft co-founder Paul Allen, says it put its super-duper-sized carrier plane through a fresh round of revved-up taxi tests last weekend at California’s Mojave Air and Space Port.

The six-engine, 385-foot-wide aircraft, nicknamed Roc, is the world’s largest airplane as measured by wingspan. It’s designed to carry up rockets for high-altitude launches in midflight.

Stratolaunch has said orbital launches could begin in the 2019-2020 time frame if the test program goes well.

Last weekend’s tests built on an initial round of low-speed runway tests in December, and were aimed at evaluating updates made to the plane’s steering and primary braking systems, Vulcan spokeswoman Alex Moji said in an email.

“We are excited to report all objectives of this test were achieved – the aircraft reached a runway speed of 40 knots (46 mph),” she said. “The data collected will be used to evaluate and update our flight simulator for crew training.”

The taxi tests and crew training should set the stage for the Stratolaunch airplane’s first flight. Once that milestone is achieved, the flight tests are expected to build up to the first in-flight test launch, and then to commercial operations.

Allen founded Stratolaunch in 2011, and in 2016 the company announced a partnership with Orbital ATK for the development of rockets that could send satellites weighing up to 1,000 pounds into orbit. The air launch system’s advantages include the ability to launch payloads into any orbital inclination, from anyplace within range of a suitable runway.

Stratolaunch was one of the stops on Vice President Mike Pence’s California tour last year, and afterward, Stratolaunch CEO Jean Floyd said Pence and other officials took part in a “rich discussion about the unique benefits of air launch.”

At the time, Floyd said the Stratolaunch system could be used for “launch missions ranging from commercial applications to critical national security needs,” including small-satellite launches for the Department of Defense.