Aerospace Prints Rocket Motors in 3-D
Jerry Fuller, a senior research associate, holds a helical star grain, printed in acrylic with a 3-D printer. (Photo: Elisa Haber)
Over the past few years, Aerospace’s Jerry Fuller has worked as a developer of rocket fuel grains. His primary responsibilities include developing mechanisms and technologies for the corporation’s picosatellite program, and other mechanics research. But his work with fuel grains is gaining increasing attention, primarily because it utilizes a versatile method of production that is just beginning to come into its own — rapid prototyping.
Rapid prototyping — also referred to as Additive Manufacturing — is a group of technologies that use computers to make 3-dimensional shapes. This form of 3-D printing transforms 2-dimensional layers of raw material into a finished product that is capable of structural nuance and complexity that might otherwise be impossible with traditional production techniques. Currently, scientists and hobbyists alike are quickly introducing new materials and products to the technology. Everything, from tennis shoes to chocolate frosting to pieces of art and even cell-based, lifelike prosthetics, is being explored as a potential product of rapid prototyping. The technology seems primed to take off in a paradigm-shifting way that could influence any number of fields including manufacturing, retail sales, scientific research, and healthcare.
Primarily, Fuller has been utilizing rapid prototyping to develop efficient fuel grains for hybrid rockets. A hybrid rocket uses a motor composed of propellants that are in two different physical states — the fuel is typically a solid while the oxidizer is either a liquid or gas. Sometimes humorously referred to as “high-pressure tire fires,” hybrid rockets will often use rubber, plastic, or paraffin wax for fuel and oxygen or nitrous oxide as oxidizer. Fuller and his colleagues at Aerospace have been printing their own fuel grains, which employ a couple of interesting design adjustments, aimed at increasing efficiency.