Time:      April 20, Thursday，15:00 PM

Place:      Room 1-315, FIT Building

Speaker:  William J. Bencze, PhD.

                 (Senior Research Engineer and GP-B Program Manager

Gravity Probe B Relativity Mission Stanford University)

Organizer: School of Aerospace and Research Institute of Information Technology, Tsinghua University

Abstract

Gravity Probe B, a NASA-sponsored astrophysics satellite developed at Stanford University and the Lockheed Martin corporation, was successfully launched on 20 April 2004 from Vandenburg AFB to test to some fundamental predictions of Einstein's general theory of relativity: the geodetic and frame-dragging effects.  The concept of the experiment is deceptively simple: place a perfect gyroscope in orbit, isolate it from all classical disturbance torques, and measure the spin axis drift caused only by the warping and twisting of space due to the gravitational mass of the Earth.  Making this simple concept a reality has proved to be confoundingly difficult and has resulted inarguably the most sophisticated scientific satellite developed to date.  This talk will examine the predictions of Einstein's theory of general relativity, describe the design of the spacecraft and the science instrumentation at its core, discuss many of the novel technologies developed and engineering breakthroughs required to build the instrument, and take a look at some early performance data from on orbit operations.

Bio

William Bencze received his Bachelors degree in Electrical Engineering from Stanford University in 1989, followed by a PhD in 1996 with a specialization in precision instrumentation and automatic control systems.  On Gravity Probe B he developed the electrostatic suspension systems now in operation on orbit, served as the overall electronics systems manager for the GP-B spacecraft prior to launch, and now is a Sr. Research Engineer and the Deputy Program Manager at Gravity Probe B. Professional interests include hybrid and nonlinear control systems, gravitational and inertial reference systems, analog electronics design, and precision instrumentation systems for space borne and terrestrial high reliability applications.