Maine Aerospace History: The Astronaut Glove Challenge
Posted On November 30, 2021
Twelve years ago this month at the Astronaut Hall of Fame in Titusville, Florida, Peter Homer of Southwest Harbor won the Astronaut Glove Centennial Challenge.
To survive in the vacuum of space astronauts wear Extra-Vehicular Activity (EVA) suits when they have to exit their spacecraft or station. These suits provide breathable air and protect the astronaut from radiation, extreme temperatures, and micrometeorites.
The air we breathe at sea level on Earth is 78% Nitrogen, 21% Oxygen, and 1% other gasses. The nitrogen and other gasses are basically useless to humans, so most spacesuits have pure oxygen environments inside. In addition to keeping the EVA suit lighter and simpler, this means that it can provide about a third of the air pressure you would experience at sea level on Earth, 14 pounds per square inch (psi), and still give its occupant a breathable atmosphere.
The only problem is that even at just 4.3 psi, by being in a pressurized space suit in the near-perfect vacuum of space, you’re basically in a very expensive balloon. Bending a balloon is difficult, especially from the inside, especially (sometimes) just using your pinky finger.
Astronauts on spacewalks invariably experience hand fatigue, and the most commonly reported EVA injuries are all hand-related. On top of that, each finger joint in the suit is a potential weak spot with a greater chance of leaking.
In 2005 NASA began releasing a series of Centennial Challenges, offering prizes for revolutionary solutions to problems of interest to NASA and the nation. The Astronaut Glove Challenge was created to find improvements to spacesuit glove design that would reduce the effort needed to perform tasks in a vacuum, and improve glove durability.
Peter Homer was already highly accomplished, with a BSME from Rensselaer Polytechnic Institute, an MS in aeronautical and astronautical engineering from Stanford, and work experience at Grumman and Lockheed Martin. His career then gravitated toward software engineering, but he took up the Astronaut Glove Challenge as a passion project.
When Peter Homer set about building a better glove, his baseline was the Phase VI Glove, designed by Hamilton Sundstrand in Windsor Locks, Connecticut. He got to drive down to their facility about a year before the competition to try a Phase VI glove in a vacuum glove box. Homer remembers, “That was a real eye-opener…At that point in time they hadn’t said ‘here’s the tests you’re gonna run,’ it was just ‘you need to do better than this.’ I had a few minutes to get the feel of the glove, and then I ran to a corner and wrote down notes of what I experienced.”
Peter made the glove from polyester dacron, a synthetic version of the cloth which defined the age of sail and is still used by NASA in thermal blankets, stainless steel fittings, and a barrier layer of thick latex similar to what balloons are made of. The materials had performed reliably in space for decades, so Peter stuck with them. “My big focus was on, how do you bend a pressurized tube of fabric?”
Homer can’t say too much about his big innovation that ultimately made his glove twice as dextrous as the Phase VI. Sources at the time reported that each knuckle was framed by thin steel rods, heated and bent to shape, as well as eighth-inch ribbon criss-crossing down each glove finger. How did these components work together? Peter did say “I came up with a way to use the pressure inside the glove against itself to make the joints more flexible.” This roughly tracks with how spiders use a combination of hydraulics and musculature within an exoskeleton to move.
The end result was a glove with a sixty-degree null zone that could allow fine-enough control for handwriting, at one full atmosphere (14.7psi) internally, in a vacuum.
Peter pointed out, “Flexibility is one half of dexterity – the other half is fit, or lining up the suit joints with the human joints.” This wasn’t such a challenge for the competition, but moving forward Peter opted to do away with standard sizing like the Phase VI glove had, and produce bespoke gloves based on hand traces or scans of each user.
The second Astronaut Glove Challenge featured three tests of durability, flexibility, and safety margins. Peter Homer and Ted Southern won first and second place respectively in the 2007 challenge, using just the inner “pressure-restraining layer” of their gloves. Each winner then had to add an outer Thermal Micrometeorite Garment (TMG), to his glove. The fully integrated gloves were then tested in 2009.
In a dexterity and flexibility test, each competitor carried out basic tasks like gripping, using tools, and touching the thumbtip to each fingertip while wearing their glove in a vacuum chamber.
In a joint force test, each glove was pressurized to 4.3psi and then put through its full range of motion, measuring how much force each movement required.
In a burst test, each glove was filled with water until it, well, burst. Homer’s glove burst at 20psi, almost five times the pressure in a modern spacesuit and at least a third higher than Earth’s sea-level pressure
In the end both gloves outperformed the Phase VI glove, but Homer’s moreso. He won the grand prize of $250,000.
In 2007 Homer founded Flagsuit LLC. The company almost immediately won contracts with Orbital Outfitters, making gloves for its Industrial Suborbital Spacesuit. In 2011 the company signed a contract with NASA to develop improved spacesuit gloves. In 2013 Homer submitted a spacesuit prototype to SpaceX, and was subsequently brought on as a contractor and then an employee for five years. After helping to design the pressure garment and automatic pressure control system of the now iconic SpaceX Dragon Launch and Entry Suit, he left to work for a custom vinyl graphics company he acquired in 2013.
Flagsuit didn’t restrict itself to pressure suits. Similar products are often used for handling materials in vacuum chambers, clean chambers, and certain medical processing tasks, so Flagsuit competed in those spaces as well. Homer also considered developing an entire pressure suit for cold-water diving, that could automatically pressurize itself to 1-2psi above the ambient water pressure, to keep water pressure from compressing thermal insulation.
In 2013 Homer mentioned work on a hyperbaric suit, a wearable alternative for the chambers which are sometimes used to help reduce inflammation for traumatic brain injuries, cerebral palsy, and more. The suit even had military application, with the possibility of operating under Harch (NBIRR-1) protocol.
What’s next for Peter Homer and Flagsuit? We can’t say for sure. What we do know is that space suit technology and design has been fundamentally changed by one man from Southwest Harbor, Maine. This isn’t the first time a Mainer disrupted an aerospace sector, and it certainly won’t be the last. Stay tuned to learn about more quantum leaps made in the Pine Tree State!