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Frame Dragging measured by Satellite Laser Ranging 2004/10/21

Einstein's theory of General Relativity predicts an effect known as "frame-dragging", which will affect the orbits of satelites. Using an improved model of the the Earth's gravity field provided by the GRACE satellites, laser ranging of the Laser Geodynamics Satellite I (LAGEOS I) and LAGEOS II showed that their orbits were altered by the predicted amount.

The original research paper is entitled A confirmation of the general relativistic prediction of the Lense-Thirring effect by I. Ciufolini and E C Pavlis, published in Nature, Volume 431, pages 958 - 960, on 2004 October 21.

The NASA news release on this research is publicly accessible.

The LAGEOS satellites are part of the group whose orbits are measured with the NASA MOBLAS-6 satellite laser ranger (SLR) operated by the Space Geodesy Group at Hartebeesthoek. It fills a large void in the global SLR network, as is shown in the SLR location map below.

slr network
credit: International Laser Ranging Service