Mojave, Calif.-based Scaled Composites announced that its Stratolaunch aircraft was towed outside for the first time to begin its ground test phase. The concept of the plane was a product of combined innovation from Microsoft co-founder Paul Allen and Burt Rutan, founder of Scaled Composites. The aircraft has a wingspan of 385 feet and is the largest composite aircraft ever built. Stratolaunch is 238 ft. from nose to tail and stands 50 ft. tall from the ground to the top of the vertical tail.

The jet’s airframe is made mostly of CFRP. Stratolaunch constructed a separate building dedicated to making the carbon composite components, one sized to the airplane’s largest parts: four wing spars each more than 62 meters long. Curing the spars required Scaled to create a mobile oven that moved along the spar given the lack of an oven big enough to hold the entire component.

Scaled Composites called the first test a “historic step” toward achieving its vision of normalizing access to low Earth orbit. A team of 300 engineers and fabricators designed, built, and hand assembled the twin fuselage vehicle as an air launch platform with a payload capacity of about 550,000 lbs.

Stratolaunch Program Director Joe Ruddy said that the Scaled test team successfully met all test objectives. A rollout of 270 feet and a return to the hangar was performed with two tugs. After the test debrief, the aircraft was pulled back out of the hangar at the end of the day and put into position for the upcoming fuel test series.

Over the coming weeks and months, Scaled Composites will be actively conducting ground and flightline testing at the Mojave Air and Space Port. rollout of 270 feet and a return to the hangar was performed with two tugs. After the test debrief, the aircraft was pulled back out of the hangar at the end of the day and put into position for the upcoming fuel test series.

“This is a first-of-its-kind aircraft, so we’re going to be diligent throughout testing and continue to prioritize the safety of our pilots, crew and staff,” said Jean Floyd, Chief Executive Officer at Stratolaunch Systems Corporation. “Stratolaunch is on track to perform its first launch demonstration as early as 2019.”