American Institute of Aeronautics and Astronautics 1 Advanced scaling model for simplified thrust and power scaling of an applied-field magnetoplasmadynamic thruster G. Herdrich 1 , A. Boxberger 2 , D. Petkow 3 , R. A. Gabrielli 4 , S. Fasoulas 5 University of Stuttgart, Stuttgart, Germany and M. Andrenucci 6 , R. Albertoni 7 , F. Paganucci 8 , P. Rossetti 9 Alta SpA, Pisa, Italy IRS and Alta are currently involved in ESA and EU (HIPER) programs aiming for the development of high power electric propulsion systems. In the framework of these programs, two 100 kW applied-field magnetoplasmadynamic thrusters (AF-MDPT) are to be developed and tested within 2011: The steady state gas-fed AF-MPD ZT2 and Alta gas-fed pulsed AF- MPD thruster. Such devices present some of the best propulsion systems if it comes to high thrust density and high specific impulse requirements, for example in orbit raising or Mars transfer mission scenarios. However, up to this day, there exists no adequate simple scaling model for AF-MPDT available to mission analysis and engine design which is addressed in this work: The classic Tikhonov model is extended and improved for steady state gas fed AF- MPDT. A simplified law of energy conservation is introduced, which can be extended with an improved anode loss model. Both models were fitted using data of existing thrusters. Further, a common envelope of both thrusters has been achieved by overlapping of operational conditions to allow a comparison of both designs. Also, power scaling and performance estimation of the 100 kW IRS AF-MPD ZT1 and the 100 kW Alta AF-MPD thruster are presented in this paper. The knowledge obtained is going to enable IRS and Alta to define the specifications of a future ESA/European AF-MPDT. Nomenclature a = speed of sound B = magnetic field density c e = exhaust velocity E D = dissociation energy E I = ionization energy F = portion of thrust h = enthalpy 1 Head of Plasma Wind Tunnels and Electric Propulsion, University of Stuttgart, Stuttgart, Germany, herdrich@irs.uni-stuttgart.de , AIAA Senior Member. 2 Research Student, University of Stuttgart, Stuttgart, Germany, boxberger@irs.uni-stuttgart.de . 3 Head of plasma modeling and simulation group, University of Stuttgart, Stuttgart, Germany, petkow@irs.uni- stuttgart.de , AIAA Member. 4 Research Engineer, University of Stuttgart, Stuttgart, Germany, gabrielli@irs.uni-stuttgart.de . 5 Professor, Head Department of Space Transportation, University of Stuttgart, Stuttgart, Germany, fasoulas@irs.uni-stuttgart.de AIAA Senior Member. 6 Chairman, Vice-President for Electric Propulsion, Alta S.p.A., Pisa, Italy. Professor, Department of Aerospace Engineering, University of Pisa, Italy. Member AIAA. 7 Research Engineer, Alta SpA, Pisa, Italy, r.albertoni@alta-space.com , AIAA Student Member. 8 Vice-President for Energy and Industrial Plasmas, Alta S.p.A., Pisa, Italy. Associate Professor, Department of Aerospace Engineering, University of Pisa, Italy. Member AIAA. 9 Project Manager, Alta SpA, Pisa, Italy, p.rossetti@alta-space.com . 46th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit 25 - 28 July 2010, Nashville, TN AIAA 2010-6531 Copyright © 2010 by the authors. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.