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Additively Manufactured Reactor For high performance, non-toxic monopropellants


TECHNOLOGY AREA(S): Space Platforms 

OBJECTIVE: Develop and demonstrate an additively manufactured reactor for a 1N AF-M315E thruster. 

DESCRIPTION: The last decade witnessed a tremendous rise in additive manufacturing capabilities. Today, numerous companies specializing in additive manufacturing are now capable producing complex parts from a variety of materials, including platinum group metals. This relatively new capability is of particular interest to the spacecraft propulsion community. Additive manufacturing of platinum group metals enables the creation of custom, complex, and often times small parts which may have been too expensive, complex, or outright impossible to create using traditional machining methods [1]. One such mechanism where additive manufacturing can play a pivotal role is in the development of reactor beds for monopropellant thrusters. The reactivity and stability of monopropellant reactor beds are the primary factors driving a thruster’s operational lifetime. State-of-the-art (SOTA) monopropellant reactor beds employ the use of granular catalysts, which degrade and shift over the thruster’s life. The degradation and shifting of granular catalysts results in a longer thrust rise time and increased chamber pressure oscillations. If these effects become too drastic, the thruster may no longer meet mission requirements and thus reach its operational end of life [2]. Additive manufacturing can offer technical solutions to replace and improve upon SOTA granular catalysts. Reactor beds which are additively manufactured can not only mitigate the issues of degradation and shifting plaguing SOTA granular catalysts, they can also be optimally designed for the various reaction stages taking place within the reactor. An optimized printed reactor bed has the potential to lead to better ignition characteristics, improved stability, a wider range of operational conditions, and increased lifetime. This solicitation seeks the development of an additively manufactured AF-M315E reactor bed for a 1N thruster. To maximize the likelihood of transition, the reactor bed should be optimized to provide an operational lifetime of approximately 40 hours and be capable of delivering a minimum impulse bit of 15mN-sec. 

PHASE I: Perform proof-of-concept analysis and experiments demonstrating the feasibility of the proposed reactor bed. Analysis and experiments should show practical manufacturability and performance/lifetime improvements over SOTA granular catalysts. 

PHASE II: Develop an additively manufactured reactor bed for a 1N AF-M315E thruster with the objective of achieving TRL 5 by the end of Phase II activities. 

PHASE III: Develop a 1N AF-M315E thruster incorporating the additively manufactured reactor developed under Phase II. 


1. Beyer, S., “Hot Firing of World’s First 3D-Printed Platinum Thruster Chamber,” Airbus Defense & Space, ESA Space Engineering and Technology, June 15, 2015.; 2. McRight, Patrick, et al., "Confidence testing Of Shell-405 and S-405 Catalysts In a Monopropellant Hydrazine Thruster." 41st AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit. 2005.

KEYWORDS: Spacecraft Propulsion, Chemical Propulsion, Additive Manufacturing, AF-M315E, Catalyst 

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