Nanoenergetic propellants offer superior energy density per unit mass, resulting in higher specific impulse compared to conventional solid propellants. This efficiency enables the use of smaller amounts of propellant to achieve the same change in momentum, making these materials ideal for space propulsion and orbital maneuvering. In addition to their exceptional gravimetric energy density, these propellants also exhibit high volumetric energy density, which supports the development of compact, modular, and scalable propulsion architectures—such as replaceable multi-thruster cartridges. This novel cartridge-based architecture leverages the high performance of nanoenergetic materials to support a wide range of orbital operations for antennas, solar panels and CubeSats. These include high total impulse maneuvers (orbit raising, deorbiting, descent, and ascent) as well as low total impulse tasks (station keeping, attitude adjustment). Each cartridge contains multiple microthrusters preloaded with solid nanoenergetic propellant. As shown in Figure 1, these thrusters can be ignited individually, in groups, or in pre-programmed sequences via onboard electronic circuitry, enabling precise, flexible maneuvering throughout the mission.

The distributed multi-thruster system addresses a key limitation of conventional solid propellant systems: their lack of reusability and refueling capability in orbit. While solid thrusters are compact, mission-ready, and maintenance-free, they are traditionally single-use. By contrast, our modular design enables scalable, multi-use functionality through the integration of numerous high-efficiency thrusters. These cartridges are compatible with a wide range of spacecraft platforms, and their design is cost-effective, and easily manufacturable—potentially even through in-situ 3D printing. A central challenge in developing these nanoenergetic multi-thruster cartridges is thermal management to ensure operational safety. Specifically, it is critical to prevent unintended ignition of neighboring thrusters or damage to surrounding structural components during firing.

To address this challenge, we conducted detailed thermal simulations using COMSOL Multiphysics, complemented by experimental tests, as shown in Figure 2. Our results demonstrate that small (millimeter-scale), 3D-printed thrusters can withstand rapid thermal pulses of a few milliseconds in duration, with thermal effects from conduction, convection, and radiation properly contained. Ongoing modeling and experimentation focus on optimizing propellant composition including the shape and size of fuel and oxidizer particles, as well as nozzle geometry, to further enhance performance and safety. This work includes modeling the oxidation reaction using the Mott framework, coupled with multiphysics simulations of unsteady flow within the nozzle. Experimental efforts are underway to synthesize and test nanoenergetic formulations and to fabricate 3D-printed multithruster arrays equipped with ignition circuits. The integration of robotics with multi-thruster cartridges offers new levels of autonomy and precision in spacecraft operations. Robotic systems can dynamically manage thruster ignition sequences based on real-time mission data, enabling adaptive trajectory control, autonomous docking, or coordinated swarm maneuvers. The modular nature of the cartridges will allow robotic servicing units to add, replace, or reposition thruster panels in orbit, extending mission lifetimes and supporting reconfigurable spacecraft architectures. 

Continued investigation into these factors is essential for improving the design and functionality of solid-propellant space propulsion systems, with broad implications for next-generation small satellite and modular propulsion technologies.