magnetic bearing test fixture is an ideal candidate for NASA's current and future requirements for thrust measurement. Magnetic bearings (MB) are a proven technology in large commercial applications such as centrifugal compressors and turbo-expanders and they are being utilized as load cells in laboratory environments. The major drawback to using MB as thrust measurements devices is the complex calibration procedure. This project will result in more accurate actuators and a greatly simplified calibration procedure. Technology currently being developed at Virginia Polytechnic Institute and State University (VT) will allow the utilization of active magnetic bearings (MB) as highly accurate force measurement systems with on-line calibration characteristics. In the proposed project, Imlach Consulting Engineering (ICE) will work with VT to develop, design, and analyze a thrust measurement system utilizing a modular system of highly efficient and accurate magnetic bearing actuators and the on-line calibration technology. The resulting thrust measurement system for rocket engine testing will to offer greater flexibility and adaptability to changing test requirements, while reducing changeover time and operating costs. The project will also develop and experimentally verify improved MB design tools which will be incorporated into advanced computational design tools for magnetic bearing (MB) actuators. Potential Commercial Application(s): Three commercial applications will be developed from this project. First, the design of the test rig will be of interest to companies requiring measurement of large axial loads generated by fluid forces (engines, compressors, turbines, etc.). Secondly, the on-line calibration procedure will be developed into a stand alone code that can be used with the digital controller of any MB system to measure in-situ bearing loads. This technology will be marketed to MB users and vendors for use in machinery and process controls and diagnostics. Finally, the improved MB design tools developed in this project will be marketed to MB users and vendors to improve the accuracy and usabiltiy of MB systems.