Building the Roc

Stratolaunch’s very large airplane has a very short name: Roc, after the mythological giant bird of prey. At least, that’s its name for now.

During a rare media tour of the company’s giant hangar at the Mojave Air and Space Port in California June 16, Chuck Beames and other company officials suggested they would be open to renaming the airplane. That’s in part because it sounds a little too much like “rock,” an inelegant moniker for what they hope will be a graceful plane. If they do, it will require a fair amount of internal re-branding, as the Roc name was everywhere, from stickers on tool cabinets to the t-shirts worn by employees building the plane.

Whatever you call the plane, one thing is clear: it’s big. When complete, it will be the largest in the world in terms of wingspan, at more than 117 meters. Surrounded by scaffolding, it looked more like a ship being built in drydock than a plane. The tail assemblies of the twin-fuselage aircraft are themselves about the average size of all the planes previously produced by Scaled Composites, the company building the plane for Stratolaunch.

The plane, about three-quarters complete, is a mix of old and new. Stratolaunch purchased two used Boeing 747 jetliners and scavenged them for parts. That included their jet engines, six of which will power the Stratolaunch plane, and their landing gear. The 747 cockpits will also be reused: one in the plane itself, and the other as a flight simulator.

The rest of the plane, though, is primarily made of custom-designed carbon composite parts. Stratolaunch constructed a separate building next door to the hangar to make those parts, large enough to accommodate the largest pieces: four spars, each 76 meters long, that anchor the plane’s giant wing.

That fabrication work is largely complete, although assembly of the plane continues. On the tour, one of those plane-sized tail assemblies was installed on the end of one fuselage, while the other was still in pieces on the hangar floor. Beames and others declined to give a schedule for completing that assembly and beginning flight tests.

At takeoff, the plane will weigh about 590,000 kilograms, including a payload of 250,000 kilograms: slightly less than the giant Antonov An-225 cargo plane, itself designed in the 1980s to ferry the Soviet Union’s Buran space shuttle. Excluding the payload, the plane’s weight will be evenly split among its 747 heritage components, its carbon composite components, and its fuel.

What that payload will be, though, still isn’t known. Stratolaunch originally planned to serve medium-class payloads, but has set aside an Orbital ATK-designed rocket in favor of unnamed alternatives that could better serve the growing smallsat market. The company has talked about establishing several “partnerships” with vehicle developers, but has not announced any yet.

“We were anticipating being able to make some announcements as a part of this conference,” Beames acknowledged in keynote at the NewSpace 2016 conference in Seattle June 21. “They’ll be coming soon, and there will be multiple ones.”

Like development of the plane itself, Stratolaunch is reticent to provide a schedule for beginning launches. Beames would only say that the system would meet its goal set by Paul Allen of beginning commercial service by the end of the decade with “healthy margins.”

And, by then, the plane should have a new name. What might that be? Beames suggested a longer, but more straightforward one, during the tour: Stratolauncher.