文档介绍：Gravity Probe B: Delay in Space and Time
By Leonard David
Senior Space Writer
posted: 06:30 am ET
31 December 2003
Decades in the making, a space probe that delves into Albert Einstein's general theory of gravitation remains grounded on Earth, caught in its own space-time continuum of technical snags, costly delays, and threats of cancellation. Scientists remain confident, however, that Gravity Probe B will provide unmatched measurements that can help reveal details about the nature of matter and the structure of the Universe.
Gravity Probe B is an experiment developed by NASA and Stanford University to precisely test two predictions of Albert Einstein's general theory of relativity, measuring how space and time are warped by the presence of the Earth and how the Earth's rotation drags space-time around with it.
The quest has not been easy.
Touted as one of the most unique experiments ever attempted in the history of science, scientists and engineers confronted challenges in gyroscope technology, materials science, the handling of ultra-cold fluids, and how best to appraise subtle gravitational effects.
With its liftoff already put on hold in the past, Gravity Probe B's launch date was again rescheduled earlier this month due to a spacecraft hardware problem. The pioneering satellite is now targeted for takeoff in April of next year.
Meanwhile, Dr. Einstein will