With the proliferation of Earth-orbiting spacecraft across commercial, exploration, and national security missions, space traffic and debris management is emerging among the major challenges facing 21st-century spacecraft. With the growth of new satellite traffic comes a corresponding and significant increase of space debris hazard and the associated risk of orbital collisions. Increasingly, there are calls for active end-of-life measures to de-orbit inactive spacecraft. An efficient, readily available, onboard propulsion system is necessary to provide in-space maneuvering and deorbit capabilities for future smallsats operating in LEO. Hybird is developing a retrobraking propulsion system, named RT-5X, whose initial application is focused on deorbit of small spacecraft in LEO. RT-5X combines the “smart” advantages of liquid propulsion (throttleability, restartablility, low impulse bit) with the operational simplicity of solid propulsion (high reliability, low-cost design, storability) in an entirely “green” propellant package. RT-5X offers advantages over the current active and passive deorbit systems, addresses the key pain points of satellite deorbit customers, and incorporates: Ultra-low costs to minimize the financial impact to mission developers Reliable, safe de-orbit transfer through controlled thrust (throttleable and restartable) Flexibility across constellation and spacecraft bus sizes High in-class propulsive performance (Isp up to 300s) Hazard avoidance maneuvering and orbit raising in addition to end-of-life servicing

RT-5X can be used to perform satellite deorbit, collision avoidance, or other in-space delta-V maneuvers on a range of NASA smallsat missions across technology demonstrations, Earth observation missions, or similar mission sets. RT-5X is aligned with NASA smallsat low-cost mission objectives for low-cost maneuver and deorbit.

Hybird’s deorbit propulsion system presents applications across commercial and defense mission sets to deorbit proliferated spacecraft constellations following end-of-mission. While the primary application is deorbit, the hybrid propulsion’s restartability allows for multiple burns and could be additionally used for collision avoidance, orbit raising, last mile delivery, or other maneuvers.