Researchers Develop High-Performance, Clean Solid Rocket Propellant

Chris Stoker, an Indiana University alumnus, and Brandon Terry, a Purdue postdoctoral research associate, are pictured burning samples of solid rocket fuel propellant in the Maurice J. Zucrow Laboratories at Purdue. (Photo: Purdue Research Foundation)

A Purdue-related startup is developing a new rocket fuel formulation that could make rockets used in military and space applications travel further, carry greater payloads, and be safer for the environment. Brandon Terry, a Purdue alumnus and postdoctoral research associate in Purdue’s Department of Mechanical Engineering, and Chris Stoker, an Indiana University alumnus, co-founded the company Adranos Energetics to develop the technology to enhance rocket performance.

Stoker said that rocket fuel hasn't changed in the last 60 years and has two major defects: inefficiency and its detrimental effects on the environment. "Current rocket fuel sources emit toxic hydrochloric acid that damages the environment and corrodes launch equipment, resulting in expensive environmental remediation costs and equipment maintenance costs," he said. "Our fuel combustion process prevents hydrochloric acid from ever forming, completely eliminating the rocket's negative effects."

In addition, Adranos's fuel formulation uses micro-explosive tendencies that produce much higher combustion efficiency and decreased flow losses, causing rockets to go farther while carrying more weight.

"This whole new realm of metallic, micro-explosive fuels has been observed by people but not yet utilized in a propellant formulation. When a rocket is moving forward, the fuel source is often discharged from the rocket plume, meaning the fuel is coming off of the fuel source and not igniting to propel the rocket forward," Terry said. "In current fuel sources up to 10 percent of the fuel is lost, however our fuel causes the previously lost fuel to micro-explode so we harness the full fuel source to propel the rocket forward with more force and at faster speeds."

The U.S. Department of Defense and U.S. allies could use the rocket fuel, Terry said. "Using our propellant, rockets could fly much farther and with a greater explosive power, keeping soldiers at a greater and safer distance," he said. "Our propellant could not only protect the life of the warfighter by giving him a competitive advantage, but also reduce corrosion to the equipment, saving significant amounts of money."

The company is in the lab-scale testing stage and has shown increased performance and elimination of hydrochloric acid in small-scale propellant combustion.

"Right now we are conducting tests to prove that the technology works as the rockets scale in size. We are currently proving functionality and performance characteristics in rocket motors that are three inches in diameter and 15 inches in length, and we will eventually scale to rocket motors that are five inches in diameter and five feet in length,” Stoker said. “Compelling results from these tests could open doors for our fuel to be adopted for use in a variety of space-launch and missile systems."