MG13 - Talk detail |
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Participant |
Muhlfelder, Barry | |||||||
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Institution |
Stanford Univerity - 452 Lomita Mall - Stanford - CA - USA | |||||||
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Session |
SG4 |
Accepted |
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Order |
Time |
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Talk |
Oral abstract |
Title |
Mission Overview & Science Instrument | |||||
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Abstract |
Gravity Probe B, launched 20 April 2004, is a space experiment testing two predictions of Einstein's theory of General Relativity, the geodetic and frame-dragging effects, by means of cryogenic gyroscopes in Earth orbit. The science instrument is comprised of four gyroscopes, each with dc SQUID readout, a cryogenic tracking telescope with two axis readout, all mounted in a quartz block structure. Precision quartz machining to 25 nm, 240 dB magnetic shielding, 10e-11 g cross track acceleration, and novel cryogenic device packaging were some of the many achievements. Analysis of the data from all four gyroscope results in a geodetic drift rate of -6,601.8 +/-18.3 mas/yr and a frame-dragging rate of -37.2 +/-7.2 mas/yr, to be compared with the GR predications of -6,606.1 mas/yr and -39.2 mas/yr, respectively. |
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