Summary: The Aero Spacelines Guppy, an oddly-shaped cargo plane, played a crucial role in the Space Race by transporting rocket parts across the United States, significantly reducing shipment times.

-Developed by Jack Conroy from various aircraft parts, including the Boeing 377 Stratocruiser, the Pregnant Guppy featured the widest cargo hold of its time.

-Its successor, the Super Guppy, offered further improvements. These planes enabled NASA to quickly transport large rocket components, accelerating the space program.

-Today, NASA still operates the last Super Guppy for transporting spacecraft components, maintaining it as a vital asset despite the challenges of sourcing obsolete parts.

Why NASA's Super Guppy Still Flies

The Aero Spacelines Guppy was an unheralded yet vital asset in the Space Race. Designed to transport rocket parts across the United States, the Guppy simplified the logistics of getting a man to the moon.

“NASA was trying to figure out a way of moving objects that were very light but very large – in other words, rocket components – from one side of the USA to the other,” aviation historian Graham M. Simons told CNN. “They needed something that had a really large fuselage in diameter, so they could ship the parts from where they were building them, mainly California, to where they were using them, mainly Florida.”

Before the Guppy entered service, during the early years of the Space Race, rocket parts manufactured in California and used in Florida had to be shipped, rather than flown. The rocket parts would travel on barges, either through the Panama Canal or the Gulf of Mexico. This meant that rocket part shipments took weeks. In a space race, in which Americans were urgently competing to post space-related firsts over the Soviets, time was critically important. The U.S. needed to accelerate their logistics. The solution would come in the form of an oddly-shaped, oddly-named cargo plane: the Pregnant Guppy.

The Pregnant Guppy – the first of several Guppy variants – had the widest cargo hold ever built at the time. Measuring almost 20 feet in diameter, the Pregnant Guppy could accommodate the rocket parts that previously needed a barge for shipment. Now, with the Guppy, the parts could be shipped in just several hours, rather than multiple weeks. 

The Guppy was primarily based on the Boeing 377 Stratocruiser, which was developed from the B-29 Superfortress. But the Guppy also incorporated parts from several other aircraft, in something of a Frankenstein recipe developed by Jack Conroy, a retired U.S. Air Force pilot.

Super Guppy: Bigger, Stronger Guppies

Conroy “pitched the idea to NASA, to convince them that they had a need for an aircraft like this,” John Bakalyar, program manager for the Super Guppy at NASA, told CNN. “When he showed a concept of what the plane would look like to NASA management at the time, they responded ‘That looks like a pregnant guppy.’ And the name stuck.”

To build the Guppy, Conroy established Aero Spacelines and got to work. Aero Spacelines’ first product, the Pregnant Guppy, was a game changer; the only aircraft capable of carrying the upper stage of the Saturn rocket upon which the Apollo program relied. The Pregnant Guppy was just the first variant, however. By 1965, Aero Spacelines had a revised version, known as the Super Guppy.

“The biggest difference was that in the original Pregnant Guppy, the tail was disconnected from the aircraft in order to load payloads into the cargo hold, whereas in the Super Guppy it’s the nose that opens,” Bakalyar told CNN. The adjustment simplified operations. The Super Guppy was also bigger and more powerful than its predecessor – 14 feet longer, with a cargo bay diameter of 25 feet, and newer, stronger, lighter engines. 

The Guppy’s utility caught the eye of Airbus, whose trans-European production scheme was logistically complicated. “Airbus had a similar logistical requirement to NASA: [Airbus] had to move around large parts of the original A300, which was being built all over Europe,” Graham M. Simons told CNN. The Airbus A300 was a twin-engine, wide-body airliner, with very large parts. With the Super Guppy, however, Airbus could ship entire portions of the A300, including the fuselage, around Europe. “Eventually Airbus acquired the rights to manufacture the Super Guppy from Aero Spacelines, so they built another two of their own and used them for many years.”

Eventually, Airbus outgrew the 1960s-designed Guppy. They decided to make their own homegrown mega-transport, the Beluga. Ironically, the Beluga was developed from the A300, which the Guppy was procured to ferry around. 

Today, just one Guppy remains in service: NASA operates the last Super Guppy, initially meant for the transportation of International Space Station components. Today, the aircraft transports Orion spacecraft components. 

“We have a dedicated team that maintains the aircraft. NASA uses it as an operational asset, so we maintain it with the intent that it is not a flying museum piece, but actually a workhorse for the agency,” Bakalyar told CNN.

Keeping the Super Guppy airworthy is a challenge. “If something breaks, you can’t just go order a replacement, because no one has been making it for 50 or 60 years,” Bakalyar told CNN. So, rather than wait around for irreplaceable Guppy components to fail, NASA has been gradually modernizing the aircraft. NASA still uses the Guppy regularly. 

“In 2019, we flew 110 hours, and we completed seven airlift missions. That’s about typical for us: we usually fly between four and eight missions a year,” Bakalyar told CNN. “There are no plans to retire the aircraft and we are focused on maintaining it as a useful asset for the foreseeable future. And we’re planning on payloads that are years into the future.” 

About the Author: Harrison Kass

Harrison Kass is a prolific defense writer with over 1,000 published articles. An attorney, pilot, guitarist, and minor pro hockey player, he joined the US Air Force as a Pilot Trainee but was medically discharged. Harrison holds a BA from Lake Forest College, a JD from the University of Oregon, and an MA from New York University. He lives in Oregon and listens to Dokken. Email the Author: [email protected]. 

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