National Aeronautics and Space Administration

Glenn Research Center

Michael Patterson

Next Generation Electric Propulsion Thruster Concept

Mr. Michael J. Patterson is a Senior Scientist/Technologist in the Research and Technology Directorate at NASA Glenn Research Center. In this position, Mr. Patterson has a lead role in propulsion research and development activities, and serves as the senior technical expert for in-space propulsion with emphasis on electric propulsion.

After some brief introduction and acknowledgements, the talk began with some background about why electric propulsion is needed. Chemical Propulsion is currently the best way to move through space. It delivers high thrust, but the amount of energy available is limited. Electric propulsion involves using electric power to create thrust. It can reduce the amount of propellant mass needed, increase payloads or make launches cheaper, and create a bigger launch date window. However, current electric propulsion designs do not have enough thrust for a launch. They create slow and steady acceleration, and they have long life times.

This is where the next generation part comes in. To have any hopes of launching, or of being able to travel through space quickly, an advanced electric propulsion thruster is needed. The current lead idea is a hybrid between two types of electric propulsion thrusters. One is the Ion Thruster which uses closely spaced, high voltage grids to create an electrostatic field of thrust. The other is the Hall Thruster which uses magnetically trapped electrons to create an electrostatic field of thrust. The goal is to combine these two designs in a single annular engine that does the job of multiple engines.

Now for where NASA is at with this project and where they are going. An annular discharge chamber was constructed at Glenn Research Center and tested successfully. The engine performed as desired in many areas but there are still some problems to work out. The research group still needs to eliminate perceived risk and high cost. The next step is further testing and evaluation before testing the second generation.