Quad channel Micro-Cathode Arc Thruster Electric Propulsion subsystem for the Ballistic Reinforced Satellite (BRICSat-P)

Abstract

CubeSat technology has been improving, and their mission has become increasingly more important in testing new designs in low earth orbit (LEO). Much of the attitude control systems and propulsion systems for small satellites in the past have relied on passive controllers and chemical micropropulsion systems. These systems have low specific impulse values and often use highly toxic fuel such as hydrazine. Electric propulsion systems have shown to have much higher specific impulse values and longer operational lives without the use of toxic propellants. There have been previous attempts to integrate electric propulsion systems onto CubeSats. However, these systems have shown to be very complex to build and require ample power generation capabilities, which occupy most of the CubeSat volume. The U.S. Naval Academy (USNA) and the George Washington University (GWU) are jointly developing components and subsystems for the first on-orbit demonstration of a novel electric propulsion system called the Micro-Cathode Arc Thruster (µCAT). A quad-channel microthruster subsystem will be used during the BRICSat-P mission. The Micro-Cathode Arc Thruster subsystem occupies less than one half of a typical 1.5U CubeSat volume, while producing specific impulse values up to 3000 s and impulse-bits of approximately 1u-Ns or better, with very low probability of spacecraft contamination. The researchers from USNA and GWU are currently working on integrating the micro-cathode thruster system onto the Naval Academy's BRICSat-P in order to demonstrate that this electric propulsion system 2 is capable of supporting CubeSat missions. BRICSat-P is a low cost 1.5U CubeSat that will demonstrate on-orbit operation of an electric propulsion system. Flight propulsion hardware is currently under development at GWU and includes a customized 32-bit microprocessor based control unit for command/telemetry/sequencing, advanced power management from unconditioned battery supply of ~6-8 VDC, an inductive energy storage unit, anode-cathode discharge components in a compact form. Each channel will be able to be operated independently and will be used for attitude control, orbit change, and de-orbit experiments. This paper will present discussion on design tradeoffs, model/simulation results of the flight hardware and its expected performance onorbit. The satellite is fully funded and scheduled to launch in March 2015.