HydROS – Hydrazine Replenishment Orbital System

HydROS is an on-orbit servicing system designed to extend the useful life of medium- and large-scale satellites by delivering hydrazine propellant in low Earth orbit. The mission concept uses a large mother ship carrying multiple daughter vehicles that transport propellant to client satellites across a wide range of service altitudes and limited inclination changes. The team developed orbital transfer and phasing strategies, propellant capacity and mass projections, spacecraft structural concepts, composite truss and shell sizing, mother-daughter separation and coupling systems, and composite overwrapped pressure vessel designs. The resulting architecture is intended to support multiple refueling deliveries from a single launch while reducing the need to prematurely replace otherwise functional satellites.