GlobalFlyer is now in the late stages of fabrication at Rutan’s famous airplane factory, Scaled Composites, in the high desert of Mojave, California. Directly across the runway from Scaled and its neighbors, a collection of civilian flight-test companies, sit dozens of grounded passenger jets, their windows draped in reflective foil, waiting for the airline industry to recover from its slump.
But things are hopping at Scaled. In one hangar, employees test equipment for what could become the world’s first successful private manned space program—a project called Tier One that is funded by Microsoft billionaire Paul Allen’s investment firm, Vulcan. (The project, which uses a mothership aircraft to launch a smaller rocket-propelled winged vehicle, is intended to prove the viability of commercial suborbital spaceflights (see “Burt Builds Your Ride to Space,” July ’03).) Other hangars contain secret projects with clients that Rutan won’t dentify—often contractors to the U.S. military. GlobalFlyer, too, was a secret from its inception three years ago until a press conference on October 23 in London—and Popular Science is the first to be shown the exceptionally sophisticated airplane in the making.
In a hangar that had to be stretched to accommodate GlobalFlyer’s 114-foot wingspan (the builders had to knock out a wall into a nearby office so one wing could poke through), team members work to complete the airplane for the commencement of the flight-test program (the first test flight will likely be in the early months of 2004). They huddle around the booms, each of which has its own tail assembly, and the central fuselage, installing flight controls and avionics, tinkering with the Williams FJ44-3 turbofan engine, and draping strips of epoxy-soaked carbon-fiber fabric over joints in the fuselage structure.
There are wing and fuselage ribs in GlobalFlyer, but far fewer than in a conventional aircraft. For the most part the composite skin is the structure. “The ribs serve to stabilize the skins, which are the primary load-carrying members,” explains Jon Karkow, the project’s soft-spoken lead engineer. “A carbon- fiber spar, shaped like an I-beam, resists the huge wing-bending loads.” Karkow shows off two examples of the composite material, a piece about a quarter-inch thick for the wings and a 3/8-inch-thick piece for the fuselage. A sandwich of carbon fiber, honeycomb and another carbon surface, the composite is substantially stronger and lighter—and pricier, and harder to manufacture—than most aircraft metals. Walking around to the ailerons on the wing, Karkow points out that there is almost no metal; even the control surfaces are connected to the airplane with composite hinges. The only metal structural components (engine and avionics not included) are the aluminum landing-gear struts and the engine mount.
Fabrication began in September 2002, after a two-year design process during which Rutan and his lead engineers determined the airplane’s configuration; this was done in collaboration with Fossett, who commissioned the airplane from Scaled after discussing the flight with both Rutan brothers. “When Steve came to us, he didn’t ask for a turbofan—he wanted to do a single-place Voyager,” Burt Rutan recalls, adding that the original Voyager configuration was chosen partially because at the time they didn’t think they could get the range out of a jet engine, which consumes much more fuel than piston engines. “But I told him I wouldn’t do a piston engine—I’ve already done it.”