Come Sail Away: Gemini Paraglider

Gemini Paraglider, also referred to as Paraglider Gemini, was an Advanced Gemini concept that used a Rogallo paraglider wing to land a Gemini spacecraft on a runway. The Test Tow Vehicle (TTV) was a full scale test article that assessed the glide and landing portions of flight. Gemini Paraglider was officially called the Paraglider Landing System Program and lasted from 1961 to 1964.

Artist's depiction of Gemini Paraglider during landing (Pinterest)

Gemini Paraglider was conceptualized in 1961 at the beginning of NASA's Gemini program. At the time, one of the program's goals was the implementation of runway landings to replace ocean splash-downs, which were expensive. NASA awarded the contract to build the test vehicles to North American Aviation, who had also recently won the contract to construct the Apollo spacecraft [1]. The vehicle was a conical boilerplate spacecraft with tricycle landing gear and ejection seats. The paraglider wing was invented by and named after Francis Rogallo and his wife Gertrude. It was a two-lobed, self-inflating cross between a kite and a parachute and later inspired the sport of hang gliding. Langley Aeronautics Research Laboratory in Virginia rebranded it as the Parawing. Full Scale Test Vehicles were built to test the deployment and inflation of the wing and were dropped from the back of a Lockheed C-130 Hercules aircraft.

Francis Rogallo testing his wing in 1959 at Langley (NASA)

Paresev 1A (Smithsonian)

While the TTV's were still being developed, USAF Dyna-Soar pilots Milt Thompson and Neil Armstrong decided to build and fly their own training vehicle, the Paresev. They figured astronauts would have to learn to fly the Gemini Paraglider at some point, so why not start early? It was essentially a tricycle-shaped one-man glider made of steel tubing under a Rogallo wing. Several hundred flights were made between 1962 and 1964 at Edwards Air Force Base in California. The Paresev was towed by a small aircraft and released at an altitude between 5,000 and 12,000 feet (1,500 - 3,657 m). Some of these flights were made by Mercury veteran Gus Grissom and newly selected NASA astronaut Armstrong.

Eight TTV flights were flown in 1964 and 1965, three of which were manned. In early '64 a series of unmanned captive flights took place. The spacecraft with its paraglider already deployed was attached to a Sikorsky S-61L helicopter by a tow rope and was carried to an altitude of 9,842.5 feet (3,000 m). Then the helicopter began its descent to the ground with the spacecraft still attached. Once these were complete, the vehicle was tested with a pilot. However, NASA Deputy Administrator George Mueller announced in February 1964 that all Gemini flights would make water landings. In May, NASA agreed to continue the Gemini Paraglider program for research purposes. The last time it was mentioned in official program history was in December, but things were just getting started.

Test Tow Vehicle-1 was flown by North American pilot Charles Hetzel on August 7, 1964. Hetzel gained experienced by flying the Paresev multiple times prior to his selection to fly the TTV. His, like the following two manned flights, began the same way as the captive flights with the vehicle being towed by a helicopter into the air. Once the towline was cut, the unpowered craft would glide to a smooth landing under its Rogallo wing on the dry lake bed at Edwards. Or at least in theory. Immediately after the line was severed, the vehicle began to fall rather than glide. It spun violently as it hurdled to the ground and forced Hetzel to eject before the vehicle smashed into the desert floor. He was later hospitalized after breaking a rib.

One of the manned TTV tests (NASA)

After the TTV-1 failure North American redesigned the vehicle and completed more radio-controlled landings. On December 19, the new pilot Don McCusker flew the next piloted drop. It went only slightly better, though, for the pilot maintained five minutes of controlled gliding before making a hard landing on the runway. At the time of touchdown, the vehicle was traveling 30 feet (9 m) per second. McCusker too was hospitalized from the shock.

The Test Tow Vehicles underwent further refurbishment and unmanned testing before it flew for the last time. The third pilot, Jack Swigert, successfully piloted the TTV to a smooth runway landing in early 1965. The following year, he joined NASA's Astronaut Corps and flew to the moon as command module pilot of Apollo 13 in 1970. By the time he landed TTV-3, however, it was too late— Gemini 3, the first manned Gemini mission, flew that March and NASA scrapped its plans to use a Rogallo wing for runway landings of spacecraft.

Test Tow Vehicle-1 (Smithsonian)

TTV-1 is now on display at the Steven F. Udvar-Hazy Center in Virginia, while TTV-2 is on loan to the National Space Centre in Leicester, England. Paresev 1A is also on display at Udvar-Hazy. What ultimately made Gemini Paraglider fail was its inability to be perfected in time for manned missions. In theory, the Rogallo wing was a capable method of replacing water landings but was just too far out of reach. More than fifty years after the final tests of Gemini Paraglider, every crewed American capsule has splashed down— except one: Blue Origin's crew capsule became the first manned capsule in US history to make a soft landing in Texas in July of 2021. Boeing's CST-100 Starliner capsule will land its first crew in White Sands, New Mexico later this year.

A National Geographic ad for Gemini Paraglider drawn by Davis Meltzer (NAT GEO)

Author's note: As of right now, Boeing Crew Flight Test-1 is scheduled for a late 2021 launch from Cape Canaveral, Florida. Thanks for reading and be sure to like, share, and subscribe!

[1] The actual flight-worthy Gemini spacecraft were built by McDonnell Aircraft.

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Bibliography

• DNews. “NASA's Amazing Gliding Gemini Capsules.” Seeker, 23 Aug. 2012, www.seeker.com/nasas-amazing-gliding-gemini-capsules-1765935785.html.

• “Gemini Paraglider Research Vehicle 1-A with Wing.” Paraglider Research Vehicle (Paresev) 1-A, Gemini | National Air and Space Museum, airandspace.si.edu/collection-objects/gemini-paraglider-research-vehicle-1-a-with-wing/nasm_A19700076000.

• “Gemini TTV-1 Paraglider Capsule.” Paraglider Capsule, Gemini TTV-1 | National Air and Space Museum, airandspace.si.edu/collection-objects/paraglider-capsule-gemini-ttv-1/nasm_A19750833000.

• Kendall, Dan. “Returning to Earth without a Splash!” The National Space Centre, 25 Oct. 2018, spacecentre.co.uk/blog-post/returning-earth-without-splash/.

• Teitel, Amy Shira. “The Paraglider: How NASA Tried And Failed To Land Without Parachutes.” Popular Science, 26 Apr. 2021, www.popsci.com/paraglider-how-nasa-tried-and-failed-to-land-without-parachutes/.

"Come Sail Away" written by Dennis DeYoung, 1977, first performed by Styx