Last updated on April 23, 2014 at 11:01 EDT
Gravity Probe B in Orbit
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Gravity Probe B in Orbit

January 18, 2013
The Gravity Probe B spacecraft is shown in orbit around the Earth, as viewed by a camera mounted on the second stage of the Delta II rocket that carried it to space. Now placed in its polar orbit of 400 miles above Earth, the Gravity Probe B spacecraft circles the globe every 97.5 minutes, crossing over both poles. Image credit: NASA/KSC