Stratolaunch Composite Air-Launch Aircraft Pulls the Wheels up During Latest Taxi Test

January 17, 2019

William Kucinski

Seattle-based Stratolaunch Systems Corporation  is fast approaching the first flight of its Stratolaunch aircraft . According to a brief social media post, the aircraft – the largest in the world in terms of wingspan – reached a speed of 136 miles per hour during a high-speed taxi test at the Mojave Air and Space Port  in Mojave, California. During the test, the aircraft generated enough lift to perform a “rotation authority maneuver” and raise its two nose landing gears off the runway. The maneuver is a key validation point in proving that the aircraft can take off successfully.

The test resulted in the Stratolaunch aircraft’s fastest taxi test yet and potentially its last before its first flight. Once the Stratolaunch makes its first flight, it will begin flighting test in order to obtain an airworthiness certificate from the Federal Aviation Administration  (FAA). Flight testing could take 18 to 24 months, according to a company statement last year.

Stratolaunch’s incremental test program began in 2017 with an initial flight target of summer 2018.

The twin-fuselage aircraft was developed and built for Stratolaunch by Mojave-based Scaled Composites , a subsidiary of Northrop Grumman Corporation , as a mobile air-launch platform for deploying space launch vehicles. The aircraft leverages proven Boeing 747  avionics, flight controls, landing gears, and six Pratt & Whitney  PW4056 turbofan engines. With an all composite airframe, the Stratolaunch aircraft is capable of lifting 500,000 pounds of payload.

Read more: So You Want to Design Aircraft: Manufacturing with Composites

According to Stratolaunch, once certified, the aircraft will be capable of up to 12 launches per year, with the potential for payload booking as close as a few days away from the launch date.

The company’s approach to orbital deployment hinges on hazard avoidance by launching above inclement weather and away from fixed-range launch schedules, which sidesteps situations that can lead to costly launch delays.

Initially, Stratolaunch will launch Northrop Grumman-provided Pegasus XL  rockets – up to three at a time, mounted on pylons underneath the mid-wing – however, Stratolaunch is currently at various points of development for three of its own proprietary launch vehicles.

These will include a 7,500 kilogram payload medium launch vehicle (MLV) optimized for short satellite integration timelines, affordable launch, and flexible launch profiles; a heavy, three-core variant of the MVL capable of deploying payloads up to 13,000 kilograms heavier payloads to orbit; and a fully reusable space plane for advanced in-orbit capabilities, crew transport, and cargo return.

William Kucinski  is content editor at SAE International, Aerospace Products Group in Warrendale, Pa. Previously, he worked as a writer at the NASA Safety Center in Cleveland, Ohio and was responsible for writing the agency’s System Failure Case Studies. His interests include literally anything that has to do with space, past and present military aircraft, and propulsion technology.

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