Description: The HYDROS project aimed to provide safe, high-performance propulsion for secondary payloads. The propulsion system is launched with only liquid water as the propellant and then uses electrolysis to split the water into gaseous hydrogen and oxygen for a simple bipropellant thruster once deployed on-orbit. The HYDROS-C was tested on the Pathfinder Demonstration Technology (PTD)-1 mission. Tethers Unlimited gathered valuable data from the flight to incorporate in future HYDROS-C and its larger HYDROS-M systems. The HYDROS-M system is baselined for several missions including SMD’s Polarimeter to UNify the Corona and Heliosphere (PUNCH) mission.

Benefits:

Launching with only unpressurized liquid water as the spacecraft propellant precursor provides safety benefits and risk mitigation which allow the system to be included on CubeSats hosted on a wider variety of missions, including to the ISS and as secondary payloads, while still providing high thrust. The system also provides a potential platform for the future ISRU of water harvested in space for refueling.