Isegoria

Everything about Stratolaunch is supersized:

It has six screaming Pratt & Whitney turbofan jet engines, salvaged from three 747s. Its maximum takeoff weight is 1.3 million pounds. It’s got more than 80 miles of wiring. Most astounding is its 385-foot wingspan, the spec that puts Stratolaunch in the history books.

One problem with ground-based rockets is that they can take off from only a small number of facilities, like the Kennedy Space Center or Vandenberg Air Force Base, where competition for launch time creates long delays. A plane-based launch would create new possibilities.

But a plane that big had other challenges. Rutan’s analysis concluded that to deliver the weight of the rocket Elias was talking about—up to 640,000 pounds—you’d need a wingspan of almost 400 feet. That wing had to be strong too. In addition to two fuselages and tons of fuel, it would be carrying a set of jet engines and that massive vehicle. Rutan planned to build the plane from nonmetal composites, rather than aluminum, to keep the weight down, but making the composite strong enough presented another problem. Rutan solved this dilemma in part with a process called pultrusion, in which a machine pulls a material at a constant rate and then bakes it until it hardens, a way to mold huge segments of the plane with a consistent strength. This technique let the engineers manufacture the very long spars that fortify the giant wing.

Rutan began working on a design, even as he realized that the odds were against it ever being built. Using traditional construction methods and materials, the price tag might stretch past a billion, perhaps even reaching the cost of a nuclear aircraft carrier. He figured he could build it more cheaply, especially if he took his scavenger mentality to the limit. “I reasoned that if I could lift out engines, pylons, landing gear, actuators, electricals, and cockpit stuff from 747s, it was doable for us,” he says.

[...]

The team worked to speed up construction by using off-the-shelf parts whenever possible, the most conspicuous example being the repurposing of three 747s. But the surface of the plane had to be created from scratch. “This vehicle has some of the largest composite components ever built in the world, made by hand by fabricators, all made by our guys,” says Jacob Leichtweisz­-Fortier, who works on the plane. The most massive pieces were 285-foot spars that give the wing its resiliency, each one weighing 18,000 pounds. The team first constructed the wing out of the gargantuan spars and built the rest of the plane around it.

The plane’s extreme size led to some unexpected complications: The scaffolding needed to assemble the wing had to be about 40 feet high. “It starts to look like a building,” Stinemetze says. “In fact, the way California treats it, it is a building. It has to meet codes for sprinklers and electrical power.” When the plane was ready to emerge from its scaffolding and get towed out of the hangar, just lowering it 2 feet to the ground took eight hours, Floyd says.

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Sharing their road map publicly for the first time, Thornburg and Floyd laid out their plans for Stratolaunch: Its first custom rocket ship will be considerably bigger than the Pegasus, able to transport multiple satellites or other payloads. This medium-size rocket is nicknamed Kraken, after the legendary Icelandic sea monster. Floyd says customers will be able to use it to get satellites into low Earth orbit for less than $30 million, a competitive price and about half of what SpaceX charges for a launch of its Falcon 9 rocket. Floyd estimates that Kraken will be operational in 2022.

Release the Kraken!

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