Session
Technical Session X: Propulsion
Abstract
The monopropellant community has been pursuing low-toxicity alternatives to hydrazine for the past two decades. One of such “green” monopropellants, known as AF-M315E, has caught attention of many by offering both improved performance and handling safety. A 0.5N-class, AF-M315E micro thruster was recently developed by Busek that can deliver >220sec vacuum Isp. Both steady-state and pulsed firings were demonstrated. The thruster, when cold, requires a small amount of pre-heating power to start which is no more than 12W or an equivalent of 1.6W-Hr energy input. The thruster is complemented by a novel piezoelectric microvalve that needs less than 200mW to operate and weighs a mere 67g. The valve features an all-welded, all-titanium wetted design for long-term propellant compatibility. It is rated for 1200sccm GN2 max flow and 1.5×10-4sccm GN2 leak rate. The valve passed environmental testing before being integrated into the thruster, and together they demonstrated a minimum impulse bit of 0.036N-sec. Busek is currently developing a 1U CubeSat propulsion system centered on the integrated 0.5N thruster and microvalve. The system is designed to be self-contained and fully loaded with propellant, which allows for simple spacecraft integration and reduced operating cost.
Development Status and 1U CubeSat Application of Busek’s 0.5N Green Monopropellant Thruster
The monopropellant community has been pursuing low-toxicity alternatives to hydrazine for the past two decades. One of such “green” monopropellants, known as AF-M315E, has caught attention of many by offering both improved performance and handling safety. A 0.5N-class, AF-M315E micro thruster was recently developed by Busek that can deliver >220sec vacuum Isp. Both steady-state and pulsed firings were demonstrated. The thruster, when cold, requires a small amount of pre-heating power to start which is no more than 12W or an equivalent of 1.6W-Hr energy input. The thruster is complemented by a novel piezoelectric microvalve that needs less than 200mW to operate and weighs a mere 67g. The valve features an all-welded, all-titanium wetted design for long-term propellant compatibility. It is rated for 1200sccm GN2 max flow and 1.5×10-4sccm GN2 leak rate. The valve passed environmental testing before being integrated into the thruster, and together they demonstrated a minimum impulse bit of 0.036N-sec. Busek is currently developing a 1U CubeSat propulsion system centered on the integrated 0.5N thruster and microvalve. The system is designed to be self-contained and fully loaded with propellant, which allows for simple spacecraft integration and reduced operating cost.
