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Schedule including this lecture.
Goddard Space Flight Center Engineering Colloquium
Date: Monday, February 3, 2003
Gravity Probe B tests two crucial effects of Einstein's General Theory of Relativity by means of orbiting gyroscopes. The requirement is for gyros with drift performance > 106 better than the best inertial navigation gyros with an angular readout good to 0.1 milliarc-seconds. The gyros are referenced to a guide star by a telescope which also must have 0.1 milliarc-second accuracy, as also does knowledge of the guide-star proper motion with respect to the absolute inertial frame. Developing the mission has depended critically on a prolonged and fruitful collaboration between physicists and engineers in many diverse areas: cryogenics, optics, precision quartz manufacturing and metrology, drag-free control, ultra-low magnetic field technology, SQUID readout, etc. An account will be given of these and the present status of Gravity Probe B as it finally approaches launch later this year.
C. W. Francis Everitt obtained his Ph.D. at the University of London (Imperial College) in 1959 for research under P.M.S. Blackett on the plate tectonics and the physics of rock magnetism. He then spent two years at the University of Pennsylvania working on liquid helium and was responsible for the experimental discovery of "third sound," a surface wave on superfluid helium films. In 1962, he joined William Fairbank and Leonard Schiff in the Stanford Physics Department as the first full-time researcher on the Gravity Probe B relativity gyroscope experiment. With Dan DeBra and Dick Van Patten of the Aero-Astro Department, he was responsible for developing many of the basic technical ideas for the satellite concept. He is now the PI of Gravity Probe B and of the joint NASA-ESA program, the Satellite Test of the Equivalence Principle (STEP). This program is currently under development to perform a new very precise orbital test of the equivalence principle. He has been an Adjunct Professor and Professor (Research) at Stanford (W. W. Hansen Experimental Physics Laboratory) since 1974.
In addition to his interests in experimental gravitation, he has written extensively on the history of physics and is author of a standard biography of James Clerk Maxwell (Scribners 1975).
Colloquium Committee Sponsor: Brent Warner
Engineering Colloquium home page: https://ecolloq.gsfc.nasa.gov