In 2014, SERDP invited proposals toward development of environmentally sustainable monopropellants, hypergolic bipropellants, and gas generators that avoid the use of hydrazines for divert-attitude control systems (DACS) and other liquid rocket propulsion systems. Two projects were selected and have since been working toward meeting the objectives stated within the Statement of Need.
The U.S. Navy and Joseph Clubb at the Naval Air Warfare Center – Weapons Division are investigating alternative fuels that replace hydrazine based formulations of liquid fuel systems. Hydrazine has been used as fuel for many rockets and spacecraft, including the space shuttle. The Navy has several mission critical propulsion systems that operate using traditional liquid hypergolic formulations that include hydrazine.
The use of hydrazine and its derivatives increase overall risk to the Department of Defense with respect to the potential for exposure to personnel and to the environment. Joseph Clubb (U.S. Navy), along with research partners from Purdue University and Frontier Aerospace, have demonstrated the capability to create bi-propellant hypergolics based on biofuels (project webpage), while researchers at Aerojet Rocketdyne are leading a project to eliminate hydrazine from monopropellants used for liquid-based gas generators (project webpage).
Outcomes from these studies will provide a great benefit towards replacing the environmentally unfriendly hydrazines currently fielded and have application towards numerous platforms across DoD and industry in. Added benefits include:
- Reduce the NFPA rating from the SOTA 4-4-3 to as low as 0-0-0.
- Eliminate the need for SCBA environment during fueling operations and decontamination.
- Provide potential ‘deep space’ fuel/oxidizer systems for beyond earth orbit environment.