WSU researchers used the ancient Japanese art of paper folding to possibly solve a key challenge for outer space travel – how to store and route fuel to rocket engines.
Researchers have developed an origami-inspired, folded plastic fuel bladder that does not crack in very cold temperatures and could one day be used to store and pump fuel. Led by graduate student Kjell Westra and Jake Leachman, associate professor in the School of Mechanical and Materials Engineering, the researchers published their work in the journal Cryogenics.
The challenge of fuel management has been a major limiting factor in space travel, largely limiting space travel to shorter trips for large amounts of cargo or to small satellites for long duration missions. At the start of the US space program in the 1960s and 1970s, researchers attempted to develop round balloons to store and pump liquid hydrogen. They missed. Each bladder would break or leak as they tried to squeeze it at the very cold temperatures required for liquid fuels. The warmest designs only lasted five cycles.
The researchers abandoned the effort and instead relied on less ideal thruster management devices. Current systems use metal plates and the principle of surface tension to handle liquid fuels, but systems are slow and can only flow fuels in small quantities, so fuel tank sizes and missions are limited.
“People have been trying to make bags for rocket fuel for a long time,” Leachman said. “Right now, we don’t take big, long trips because we can’t store fuel for long enough in space. “
Through a literature search, Westra came across an article in which researchers developed origami-based bellows. Researchers began to study origami in the 1980s and 1990s with the idea of using its complex shapes and interesting mechanical behavior. The origami folds distribute the stress on the material, making it less likely to tear. Using a thin sheet of Mylar plastic, Westra and his collaborators at the Hydrogen Properties for Energy Research Lab decided to apply the design he saw to developing a fuel bladder. .
“The best solutions are the ones that are already out of the box and then you can transfer to whatever you’re working on,” Westra said.
Having never tried origami before, he said it took a few tries and hours with a Youtube video to figure out how to fold the bellows. When folded, he tested it in liquid nitrogen at around 77 degrees Kelvin. Researchers have found that the bladder can be squeezed at least 100 times without breaking or leaking in cold weather. They have since demonstrated the bellows on several occasions, and it still has no holes.
“We think we’ve solved a key issue that was holding everyone back,” Leachman said. “We’re a little excited about this. “
Researchers are now starting to carry out more rigorous testing. They plan to do tests with liquid hydrogen, assess how well they can store and expel fuel, and compare their bladder flow rates with current systems. Westra recently received a graduate scholarship from NASA to continue the project.
“Kjell’s success is a perfect example of great WSU students who study what is out there and then find themselves in the right place at the right time to make it happen,” said Leachman.