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“They’ll never get off the ground,” warned detractors of Aero Spacelines’ Guppy series of colossal cargo airplanes. (JIM KOEPNICK)

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NASA’s Super Guppy Turbine looks like it should be impossible to fly, or at the very least, like it should bumble about the heavens and then clatter to Earth the minute gravity figures out it’s up there. It weighs 50 tons. It is an airplane big enough to swallow other airplanes—a hangar with wings. But when pilots Rick Hull and Terry Pappas bring the Guppy in for a landing at NASA’s Marshall Space Flight Center in Huntsville, Alabama, on a clear December morning, the airplane descends with the stately grace of a steamship cruising into harbor. 

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This Guppy is the last in a series of gargantuan cargo aircraft that have been wowing bystanders since 1962, when its grandmother, the Pregnant Guppy—at that time the world’s largest airplane—did the heavy lifting that helped get NASA to the moon on time. Since then, NASA has used the Pregnant Guppy progeny to ferry equipment for Skylab and the International Space Station. Today, this Guppy is picking up a duplicate of the 10-foot-wide, 2,400-pound rotary joint that turns the solar panels on the space station; the original is malfunctioning, and astronauts and engineers in Houston will need the duplicate to devise a fix.

The Guppies also influenced a generation of airplanes designed for more terrestrial matters: Airbus Industrie’s Beluga and Boeing’s Dreamlifter carry aircraft subassemblies between plants in different countries. Pumped-up airplanes are rare—only one of eight Guppies built still flies, there are but five Belugas, and Boeing plans to build only four Dreamlifters.  Their proof of principle, the Pregnant Guppy, is largely responsible for making good on President John F. Kennedy’s 1961 promise to put a man on the moon “before this decade is out.”

The brainchild of Aero Spacelines partners Jack Conroy and Lee Mansdorf, the Pregnant Guppy was conceived to haul 40-foot-long Saturn S-IV-B rocket stages from California to Cape Canaveral, Florida. Previously, NASA had been shipping them through the Panama Canal, but the voyage was far too slow for a race to put a man on the moon by the end of the 1960s, and the long exposure to sea air put the stages at risk for corrosion.

NASA had toyed with a few other concepts, including piggybacking the rocket stages on an Air Force C-133 transport, or slinging them beneath a blimp. But these solutions weren’t aerodynamic and still would have exposed sensitive parts to the elements. Conroy and Mansdorf had another idea: transform Mansdorf’s stockpile of Boeing B-377 Stratocruisers, purchased just as the Jet Age was making the propeller-driven airplanes less desirable, into the U-Haul of the skies. 

First, Aero Spacelines stretched a Stratocruiser fuselage by adding a 16-foot aft section. Then the engineers built a bigger fuselage atop it: More than 19 feet in diameter, it was braced to the original with lumber, to be cut away if the airplane survived test flights. Another key modification would later define the Pregnant Guppy: a tail section that had to be removed for cargo loading. The design necessitated disconnecting the flight control cables each time the tail was opened.

But there was a problem: Aero Spacelines had built the airplane without actually getting a NASA contract. As soon as the Guppy passed its air trials, surprising those who had predicted a fiery crash, the nearly broke Conroy set off in it for Huntsville to demonstrate his concept to Marshall’s famous director, Wernher von Braun. The still-cautious Federal Aviation Agency gave Conroy special clearance, provided he didn’t fly over cities.

Von Braun was so impressed he insisted on taking the Guppy for a spin, much to the alarm of his staffers, who pointed out that it was still held together with two-by-fours. Worse, the airplane, with a full load of fuel to simulate a full payload, was super-flammable. Nevertheless, once von Braun took the pilot’s seat, the irrepressible Conroy secretly told the flight engineer to shut down the two portside engines—a sly demonstration of the airplane’s power. When von Braun finally realized that he was flying comfortably on two engines, Conroy, according to legend, coolly responded, “Oh, we do that all the time to save fuel.” (In fact, says Daren Savage, who runs a Web site called AllAboutGuppys.com, “Conroy was actually standing on the rudder so that von Braun didn’t really know how much effort it was really taking to fly this plane.”)

Aero Spacelines soon had its contract.  The Pregnant Guppy promptly reduced NASA’s cross-country transit time from 18 days to 18 hours. “It enabled them to keep the schedule that they needed so they didn’t have to scrub any launches,” says Savage.

With proof that airplanes could safely be super-sized, NASA ordered an even bigger one. Dubbed the Super Guppy, it had a 141-foot-long body and 25-foot-wide fuselage. A hinged nose that could swing open 110 degrees for loading replaced the removable tail. In the meantime, Airbus, which manufactures aircraft components in France, Germany, Spain, and the United Kingdom, was also warming to the Guppy concept. In the early 1970s, Airbus began using four Super Guppy Turbines—a generation with Allison 501-D22C turboprop engines—to shuttle subassemblies internationally, saving time and eliminating bureaucratic hassles. (However, it also led to the taunt that every Airbus took its first flight on a Boeing.) “By using aircraft, you add flexibility to your industrial process,” says Bruno Gutierres, head of new programs and development for Airbus’ logistics and supply chain. “You are not dependent on weather conditions, for example, like you are with surface transports.”

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