Green Propellants

Spacecraft have used hydrazine as a monopropellant since the 1960s. The benefits include high thrust performance from a relatively low mass and volume, room temperature storable, and relatively low complexity.  The downside is hydrazine is highly toxic and handling personnel must wear Personal Protection Equipment (PPE).  Green propellants such as HAN-based ASCENT developed by AFRL have emerged as viable replacements for hydrazine.  ASCENT is much less toxic, is room temperature storable, and has high thrust performance from even lower mass and volume needs as compared to hydrazine-based systems.  We are developing an ASCENT-based 500mN thruster with plans to scale up to 1N, 10N, and higher.

Electric Propulsion

The use of electric propulsion such as Hall Effect, Pulsed Plasma Electromagnetic, and arcjet thrusters for CubeSat propulsion or SmallSat orientation provides very effective performance.  There are opportunities for improvements that address common issues such as electrode erosion and limited life propellants.  We are developing an arcjet thruster array that uses ammonia as a propellant.  Ammonia is a by-product of ASCENT decomposition and we also plan to develop a hybrid chemical-electric thruster.

Propellant Reservicing

NASA, DoD, and commercial endeavors are actively developing methods to extend spacecraft lives through reservicing.  Following rendezvous and docking, methods include mechanical attachment of a propulsion module to reboost or deorbit and coupling connections for tank-to-tank transfers of propellant.  We have a unique approach to reservicing that is modular and rapid.  We are maturing our design and plan orbital demonstrations leading to operational deployment.