Washington State researchers are taking inspiration from the ancient art of origami to create a foldable bladder that can be used to contain rocket fuel at cryogenic temperatures. Graduate student Kjell Westra, engineering professor Jake Leachman and their colleagues at WSU’s Hydrogen Properties for Energy Research Laboratory, or HYPER Lab, describe their research in the journal Cryogenics. They are trying to figure out the best way to store and pump super-cold rocket propellants such as liquid hydrogen. Leachman said in a press release, “Folks have been trying to make bags for rocket fuel for a long time. We currently don’t do large, long-duration trips because we can’t store fuel long enough in space.”
Early in man’s conquest of space, engineers tried to develop balloon type bladders that could be used to manage the storage and flow of liquid hydrogen. However, those early bladders had a tendency to leak or shatter when they were squeezed. The best early designs failed after only five cycles of squeezing and relaxing. Current storage systems for rocket fuel use metal plates and surface tension to manage fuels.
The researchers at WSU carried out a literature search before they began their experimental work. One of the articles they found mentioned the development of a bladder that took advantage of origami which is the ancient Japanese art of paper-folding. The article talked about the use of n origami design for medical stents or deployable solar sails for spacecraft. Westra and his team decided to adapt the designs in the article to the manufacture of rocked fuel bladders. Westra said, “The best solutions are the ones that are already ready-made and that you can then transfer to what you’re working on.”
After learning how to correctly fold thin sheets of plastic with origami techniques, Westra tested his origami bellows in a vat of liquid nitrogen at a temperature of three hundred and twenty degrees below zero Fahrenheit. The researchers were expecting that the origami folds would help spread out the stress on the plastic materials and lower the risk of tearing. Their experiments were successful. The origami folded bladder could be squeezed and relaxed over a hundred times at extreme temperatures without leaking or breaking. Leachman said, “We think we’ve solved a key problem that was holding everybody back.” The next phase of research will be to conduct similar experiments with liquid nitrogen at four hundred and twenty-three degrees below zero Fahrenheit.
Westra and his team have been awarded a NASA graduate fellowship to keep working on the project. Their work has also received funding from the Joint Center for Aerospace Technology Innovation, an economic development initiative backed by Washington State as well as the Blue Origins space venture. Leachman said, “Westra’s success is a perfect example of great WSU students studying what’s out there, and then being in the right place at the right time to make it happen.” In addition to Westra and Leachman, Francis Dunne, Stasia Kulsa and Mathew Hunt also worked on the study.