A Craft Born from the Channel
To understand the Gossamer Penguin, you have to start with its older sibling. In the late 1970s, the aeronautical engineer Paul MacCready and his team — a small, close-knit group of family and engineer friends, later associated with his company AeroVironment — were chasing the Kremer Prize, a £100,000 award offered by British industrialist Henry Kremer for the first human-powered crossing of the English Channel. MacCready's earlier aircraft, the Gossamer Condor, had already won the first Kremer Prize in 1977 by flying a figure-eight course on pedal power alone. The Channel was the next, much harder challenge.
MacCready's answer was the Gossamer Albatross — a delicate, 96-foot-wingspan aircraft of carbon fiber, polystyrene, and Mylar, weighing only 71 pounds without a pilot. On June 12, 1979, the cyclist Bryan Allen pedaled the Albatross across the Channel from England to France in 2 hours and 49 minutes, winning the prize and rewriting what most engineers thought was possible.
What's less widely known is that MacCready's team didn't build just one Channel-attempt aircraft. They built three. The primary was the original Albatross. The second was the Gossamer Albatross II, a backup with the same dimensions. And the third was something a little different: a smaller, lighter, more agile variant — three-quarters the scale of the Albatross, with a 71-foot wingspan instead of 96 — designed to be faster and more responsive in the air. That third aircraft was the Gossamer Penguin.
It existed, in other words, before anyone on the team had given serious thought to solar flight. The Penguin was conceived and built as a human-powered aircraft — a quicker, sharper sibling to the Albatross, held in reserve in case the larger craft couldn't handle the Channel conditions. Its first flight, in May 1979, was on pedal power.
The Albatross succeeded, of course. The Channel was crossed, the prize was won, and the Penguin's original mission quietly evaporated.
A Second Life Under the Sun
What MacCready did next is what turned the Penguin into something historically significant. With the human-powered chapter closed, the team had a featherlight, fully functioning airframe sitting around with no purpose. They also had a working relationship with Robert J. Boucher of AstroFlight, Inc., the engineer who had designed the very first solar-powered aircraft — the uncrewed Sunrise II, which flew in 1974 — and who became a key consultant on the next project.
The idea was straightforward: take the Penguin, pull out the pedal mechanism, install an electric motor, mount a solar panel above the fuselage, and see whether you could fly a human being on sunlight alone. The conversion was sponsored by DuPont in exchange for publicity for the company's patented synthetic materials, with AstroFlight supplying the motor and solar cells.
The result was an airframe in two distinct lives. As a human-powered craft, the Penguin had been the Albatross's quick cousin. As a solar craft, it became something no one had quite built before.
Construction and Materials
The Penguin inherited its construction philosophy almost wholesale from the Albatross — and that philosophy was, in a word, obsessive. Every gram mattered.
The primary structure was a frame of thin carbon fiber tubes, providing the load-bearing spine and wing spars. Wing ribs were cut from expanded polystyrene — the same kind of lightweight foam used in packaging — and shaped to the airfoil profile. The entire skeleton was then wrapped in a transparent skin of Mylar PET film, the DuPont polyester sheet that gives all the Gossamer aircraft their distinctive ghostly appearance in photographs. Control surfaces and bracing relied on Kevlar lines and similar synthetic cordage.
The final airframe weighed just 68 pounds without a pilot, despite spanning 71 feet with a wing area of 297 square feet. For comparison, that's roughly the wingspan of a small commuter airliner, achieved at less than the weight of a large dog.
The solar conversion added an AstroFlight Astro-40 double-brush DC electric motor with a 133:1 reduction gear driving the propeller. Power came from a 541-watt solar panel made up of 3,920 photovoltaic cells, mounted on a separate panel above the fuselage. Crucially, that panel could be tilted toward the sun — a necessary compromise because the Penguin's wing was a curved Mylar airfoil, not a flat surface that could hold cells directly.
The published record on the Penguin describes a 28-cell D-type nickel-cadmium battery pack carried on board, used during the early test flights before the solar array was installed. What happened to those batteries afterward is less clear. The aircraft in our care doesn't include them today — most likely, we suspect, because they were removed before the Penguin went on display: nickel-cadmium cells are heavy and prone to leakage over time, neither of which is desirable for a museum-suspended artifact. Our working hypothesis is that, when they were on board during the solar-powered flights, the batteries functioned in a capacitor-like role — smoothing the variable output of the solar cells into a steadier supply for the motor — rather than serving as a primary power source. The documentation is thin, however, and we don't fully know. It's one of the open questions we hope to answer as we continue working with the artifact.
It was a fragile aircraft. The combination of the lightest possible structure, the lowest possible power requirement, and the lowest possible flying speed meant that almost any wind or turbulence could throw it around dangerously. Flights had to take place at dawn, when the air was still — but dawn is also when the sun is low in the sky, which is exactly why the tilting solar panel was necessary.
The First Flights
The Penguin's first solar flights took place at Minter Field, near Shafter, California, in the spring of 1980. The first pilot wasn't a professional. It was Marshall MacCready, Paul's 13-year-old son, who weighed about 80 pounds — light enough to give the underpowered aircraft a real chance of lifting off. Marshall's role was to determine how much power was actually needed, to help optimize the airframe and propulsion system, and to do the early dangerous work of figuring out how the thing handled in the air.
On May 18, 1980, Marshall flew the Penguin roughly 500 feet on direct solar power alone — the first flight in history in which a human-piloted aircraft sustained itself in the air on sunlight in real time, with no battery buffering. It was a quiet milestone, performed without ceremony.
The project pilot — the one whose name is in the history books — was Janice Brown, a Bakersfield schoolteacher and licensed glider pilot who weighed slightly under 100 pounds. Brown flew the Penguin approximately 40 times during testing. On August 7, 1980, in front of a crowd at NASA's Dryden Flight Research Center on Rogers Dry Lakebed, she flew it 1.95 miles in 14 minutes and 21 seconds. That public demonstration is the flight most often cited as the Penguin's defining achievement.
A Contested Title
The Gossamer Penguin is often described as "the first manned solar-powered aircraft." That claim is partly true, partly contested, and depends entirely on how you define your terms.
The Penguin was not the first crewed aircraft to fly using energy from the sun. That distinction belongs to the Mauro Solar Riser, designed by Larry Mauro and built from a modified Easy Riser hang glider. On April 29, 1979 — more than a year before the Penguin's solar flights — Mauro flew the Solar Riser at Flabob Airport in California, reaching about 40 feet of altitude and covering roughly half a mile. The British Solar One followed in June 1979.
What sets the Penguin apart is the method of solar flight. The Mauro Solar Riser used its solar cells to charge an onboard battery on the ground; the aircraft then flew on stored battery power, with the solar contribution being indirect. The Penguin's flights are credited as direct-solar achievements — with the panel producing electricity that drove the motor as the flight happened. Any batteries on board appear to have served a regulating function rather than supplying primary power, though, as discussed earlier, the documentation is incomplete. The Penguin remains the aircraft most commonly cited as the first to fly a human being on the power of sunlight as it fell on the wing.
There's also a smaller "first" buried inside the project: Marshall MacCready's quiet May 18 flight technically preceded Janice Brown's public August 7 demonstration. Marshall flew first; Janice flew officially. Both flights count, depending on what you're counting.
The most honest framing is the one used by the engineers who studied the era: the Penguin demonstrated, for the first time, that a human being could fly on sunlight alone.
Purpose Beyond the Flight
The Penguin was never meant to be a finished aircraft. It was a research platform — a stepping stone. The whole point of the program was to gather practical data for something better.
That something better became the Solar Challenger, the team's next design, which incorporated every lesson the Penguin had taught. Where the Penguin's wing was curved and required a separate tilting solar panel, the Challenger was built with a flat-topped wing so cells could be laminated directly to its surface. Where the Penguin was fragile and could only fly in dead calm, the Challenger was sturdy enough to handle real weather. On July 7, 1981, the Solar Challenger flew 163 miles from Pontoise-Cormeilles outside Paris to Manston Royal Air Force Base in England, reaching an altitude of 11,000 feet — entirely on direct solar power, with no batteries on board at all.
The Penguin made that flight possible.
From Lakebed to Lobby
After its public demonstration at Dryden, the Penguin spent a few years on the road — appearing at trade shows, science expositions, and museum exhibits as a touring artifact of the early solar-aviation era. Then, in the mid-1980s, the aircraft was donated to The Science Place, the beloved Dallas science museum in Fair Park.
For approximately a decade, the Penguin hung in the museum's lobby — a 71-foot, otherworldly object suspended above visiting schoolchildren. For an entire generation of Dallas kids, it was simply part of what The Science Place looked like.
But the same lightness that had made the aircraft remarkable in flight made it terrible at sitting still. The Mylar skin, which had been engineered to weigh almost nothing, began to embrittle and tear. The polystyrene wing ribs aged and crumbled. By 1995, the Penguin was in poor enough condition that the museum loaned it out — to the Cavanaugh Flight Museum in Addison, Texas, which planned to put it on display.
Those plans never materialized. The Penguin needed more space and more restoration work than the Cavanaugh could provide, and it ended up in storage. In 2006, The Science Place merged with another museum (a transition that eventually became the Perot Museum of Nature and Science in 2012), and in the shuffle, the records of the Cavanaugh loan were misplaced. By the late 2000s, almost no one remembered that one of the world's most important solar aircraft was sitting in a hangar in Addison.
Rediscovery
The Penguin was not high on our recovery list — for the simple reason that we didn't know it had survived. Like much of the Science Place's collection, it had quietly slipped out of institutional memory after the 2006 merger. We had childhood recollections of something enormous and translucent suspended above the lobby, but no paperwork to confirm what we were remembering, no provenance trail, and no reason to assume the aircraft hadn't been scrapped sometime in the intervening decades.
In January 2024, working through what survived of the Science Place's loan records, we found it: a 1995 agreement documenting the Penguin's transfer to the Cavanaugh Flight Museum in Addison. The loan had never been formally closed. Cavanaugh's planned display had never materialized. As far as the paperwork was concerned, the aircraft was still out on loan — it had just been sitting in storage, untouched, for nearly thirty years.
It was still there. In pieces, with the Mylar in worse shape than we had hoped and the polystyrene about where we expected it to be — but all of it, recognizably, the Gossamer Penguin.
What Comes Next
The Penguin in our care today is not the polished museum object that hung from the Science Place ceiling. Decades of storage have taken their toll on materials that were never designed for longevity in the first place. The Mylar will need replacement or extensive stabilization. The polystyrene ribs will need careful conservation and some limited reproduction. The carbon fiber spine is, by all accounts, the most resilient part of the aircraft — much as it was when MacCready's team first selected the material for its strength-to-weight ratio in 1979.
Our long-term plan is to reassemble the Gossamer Penguin and display it where it can be seen by the public again. It belongs in the air, conceptually, if not literally — visible, interpreted, and understood as the strange little research aircraft that helped prove a person could fly on sunlight.
For now, it quietly rests in our archives, in pieces, waiting.
If you have photographs, documents, or memories of the Gossamer Penguin — from its years at The Science Place, from the Cavanaugh, or from anywhere earlier in its history — we'd love to hear from you.