The Stratolaunch aircraft completed its first low-speed taxi test recently. For the first time, Stratolaunch Systems Corporation reports, the aircraft travelled down the runway under its own power, using all six Pratt & Whitney turbofan engines.

Stratolaunch is the world’s largest aircraft by wingspan and is the largest all-composite plane ever built. The company’s stated aim is to “make access to space more convenient, reliable, and routine”. Stratolaunch is currently under construction at the Mojave Air & Space Port in California, and is slated to be fully operational by the end of 2020.

The purpose of the latest trial was to test the aircraft’s ability to steer and stop. A ground team monitored a number of systems, including steering, braking, anti-skid and telemetry.

Stratolaunch CEO, Jean Floyd, commented: “We are excited to report all objectives of this test were achieved – culminating to the aircraft traveling down the runway at 25 knots (28 miles per hour).”

George Bugg, aircraft program manager, added: “This was another exciting milestone for our team and the programme. Our crew was able to demonstrate ground directional control with nose gear steering, and our brake systems were exercised successfully on the runway. Our first low speed taxi test is a very important step toward first flight. We are all proud and excited.”

The next phase of taxi testing will include increased speeds.