In propulsion system design, engineers have long faced a trade-off between solid and liquid rocket fuels. Each has advantages and disadvantages, and in an effort to try to min/max the efficacy of different types of fuel, researchers have long placed an emphasis on a hybrid between solids and liquids - in other words they’ve been working with gels. Unfortunately, gels have their own sets of problems to deal with. But a new paper published by Pranay Mudaliar and Jerin John of Concordia in the journal Langmuir uses an uncommon ingredient to elegantly solve some of those problems, but which is typically used in a completely different area of human activity - lecithin.

Solid rocket boosters, like those that powered the Space Shuttle, are very stable, durable, and quick to ignite. However, they are also impossible to turn off - you have to burn through all the propellant at once.

Liquid fuel, on the other hand, is much more flexible, much like automotive fuel.…