Thruster

CubeSat Ambipolar Thruster (CAT)


CAT being set up for an experiment

Developed
2013

Tested at PEPL
2013 – 2016

Developer
PEPL, NASA, DARPA, Phase Four Inc.

The CubeSat Ambipolar Thruster (CAT) is a thruster designed as a propulsion system for CubeSats. It relies on a radio frequency antenna to create a plasma in a ceramic liner. The radiofrequency wave efficiently ionizes the Xenon propellant and heats the electrons. Through the process of ambipolar diffusion, these electrons exit the generation region at high speeds. The resulting charge imbalance provides an electric field that accelerates the ions, generating thrust.

To further convert the electron thermal energy into thrust, a magnetic nozzle is applied. A magnetic nozzle consists of a diverging magnetic field that forces the plasma to expand outwards as well, cooling it and converting its thermal energy into directed thrust. The nozzle also induces azimuthal electron currents which in turn produce a magnetic field in the direction opposite of the nozzle. In this manner, the electrons form an electromagnet that pushes off of the thruster magnetic field, enhancing thrust.

Furthermore, CAT will be able to operate on a wide range of propellants. While a supply of Xenon is still ideal, it is difficult to bring such a supply into space. For extended missions throughout the solar systems, small thrusters must be able to adapt to whatever propellant they have nearby, a concept known as In-Situ Resource Utilization, ISRU. A thruster able to use a variety of propellants such as CAT will extend the range of small satellite missions.

Selected Publications


  • Performance of the H9 Magnetically Shielded Hall Thrusters

    Cusson, S. E., Hofer, R. R., Lobbia, R. B., Jorns, B. A., and Gallimore, A. D.

    35th International Electric Propulsion Conference, Atlanta,GA, IEPC-2017-239, 2017

  • The H9 Magnetically Shielded Hall Thruster

    Hofer, R.R., Cusson, S.E., Lobbia, R.B., and Gallimore, A.D.

    35th International Electric Propulsion Conference, Atlanta,GA, IEPC-2017-232, 2017

  • Dispersion relation measurements of plasma modes in the near-field plume of a 9-kW magnetically shielded thruster

    Brown, Z. A., and Jorns, B. A.

    35th International Electric Propulsion Conference, Atlanta, GA, IEPC-2017-387, 2017

  • Experimental Evidence for Ion Acoustic Solitons in the Plume of a Hollow Cathode

    Georgin, M.P., Jorns, B.A., and Gallimore, A.D.

    2nd Space Propulsion Conference, Sevilla, Spain, SPC18-403, May 14-18, 2018

  • Ion Acoustic Turbulence in the Hollow Cathode Plume of a Hall Effect Thruster

    Cusson, S.E., Brown., Z, Dale, E.T., Jorns, B.A., and Gallimore, A.D.

    54th AIAA/SAE/ASEE Joint Propulsion Conference, Cincinnati, OH, AIAA-2018-4509, July 9-11, 2018

  • Non-Invasive Characterization of the Ionization Region of a Hall Effect Thruster

    Dale, E.T. and Jorns, B.A.

    54th AIAA/SAE/ASEE Joint Propulsion Conference, Cincinnati, OH, AIAA-2018-4508, July 9-11, 2018

  • Spatial Evolution of Plasma Waves in the Near-field of a Magnetically Shielded Hall Thruster

    Brown, Z. and Jorns, B.A.

    54th AIAA/SAE/ASEE Joint Propulsion Conference, Cincinnati, OH, AIAA-2018-4423, July 9-11, 2018