Iodine Hall Thruster Propellant Feed System for a CubeSat

Abstract

The components required for an in-space iodine vapor-fed Hall effect thruster propellant management system are described. A laboratory apparatus was assembled and used to produce iodine vapor and control the flow through the application of heating to the propellant reservoir and through the adjustment of the opening in a proportional flow control valve. Changing of the reservoir temperature altered the flowrate on the timescale of minutes while adjustment of the proportional flow control valve changed the flowrate immediately without an overshoot or undershoot in flowrate with the requisite recovery time associated with thermal control systems. The flowrates tested spanned a range from 0-1.5 mg/s of iodine, which is sufficient to feed a 200-W Hall effect thruster.

Iodine Hall Thruster Demonstration Mission Concept and Development

“…The board has its own general interface capabilities and is now typically referred to as the auxiliary board. 8 It is unclear but currently doubtful that the auxiliary board functions can be completely absorbed within the iSAT flight system PPU. One limit is the volume available within the PPU, but the auxiliary board also provides custom avionics likely to change for future iodine flight systems, and as such these avionics should be maintained separately outside of any industry provided, flight-qualified PPU.…”

“…The efforts performed to-date are the subject of Ref. [8] and are only briefly summarized here. Unlike xenon, iodine is a solid under ambient conditions.…”

CubeSat Lunar Positioning System Enabled by Novel On-Board Electric Propulsion

“…For CubeSats particularly this is of importance due to restrictions on pressurized gases for piggyback launches. Construction and testing of an Iodine feed system for the iSAT 12U CubeSat was reported by Polzin and Peeples [31], where reservoir heating was used together with a flow control valve to achieve control over the Iodine gas mass-flow. Some challenges remain, however, regarding Iodine deposition (solidification) in plumbing and fluid control systems, thermal control and inertia, responsiveness in micro-gravity conditions, as well as issues due to the highly corrosive nature of the propellant.…”

Overview of Iodine Propellant Hall Thruster Development Activities at NASA Glenn Research Center

“…Feed system development conducted by NASA MSFC has focused on sublimation control, high-voltage isolation, avoidance of propellant condensation, and iodine compatibility. 9,10 The PPU development activities at Busek are focused on the development of a flight 200 W compact PPU for demonstration on iSAT and the development of an engineering model 600 W PPU. NASA GRC is supporting the Busek PPU activities by developing thermal models of the PPUs.…”