GP-B Post-Flight Analysis—Final Report - Gravity Probe B - Stanford ...

In the months following publication of Schiff ’s paper, Schiff, Fairbank and Cannon continued to develop andrefine various aspects of the relativity gyroscope experiment. One early question was the feasibility of flying areference telescope. Cannon, being familiar with NASA’s forthcoming Orbiting Astronomical Observatory(OAO) from conversations with Dr. Nancy Roman of NASA Headquarters was able to dispel this concern. InJanuary 1961, Schiff and Fairbank sent a two-page letter proposal to NASA’s Office of Space Sciences, outlininga possible approach to the relativity gyroscope flight experiment.Figure 2-2. GP-B Co-founders and Nancy Roman. Clockwise from top left: Leonard Schiff (~1970),William Fairbank (~1988), Robert Cannon (2005), and Nancy Roman (2005)During Roman’s first year at NASA, the Office of Space Sciences had received a number of proposals on spacetests of general relativity, including this one. Roman and other NASA scientists were eager to support suchresearch; however NASA realized that evaluating these proposals required input from scientists and engineerswith highly specialized knowledge in this field. At Roman’s initiative, a NASA-sponsored conference onexperimental tests of relativity was held at Stanford under the chairmanship of the distinguished relativist H. P.Robertson of Caltech, on July 20-21, 1961, with a large attendance of physicists and aerospace engineers,including Schiff and Cannon.Also present from Stanford’s Aero-Astro Department were two of Cannon’s graduate students: Daniel DeBra,who was finishing his Ph.D. while heading up the Dynamics & Controls Analysis Group at Lockheed Missiles &Space Company (LMSC, now Lockheed Martin), and Benjamin Lange, also from Lockheed, who was juststarting his graduate studies in the Stanford Aero-Astro Department. Lange independently proposed theconcept of a drag-free satellite during the course of the meeting, and it became the subject of his doctoraldissertation. DeBra, now a Professor Emeritus in Stanford’s Aero-Astro Department, has been a Co-PI on GP-Bsince the late 1960’s. Separately, in the early 1970s, he led the development, in collaboration with Johns HopkinsGravity Probe B — Post Flight Analysis • Final Report March 2007 27