NASA Launches ‘Einstein’ Satellite

LOS ANGELES – NASA launched into orbit Tuesday a $750 million satellite meant to erase any doubt about two of Albert Einstein’s fundamental predictions about the universe.

The Gravity Probe B satellite blasted off from an oceanside pad at Vandenberg Air Force Base aboard a Delta II rocket. The satellite separated from the rocket 75 minutes later and began its 18-month mission, officials said.

The launch of the 6,800-pound, Lockheed Martin Corp.-built spacecraft marked the end of the longest development period of any mission in the history of the National Aeronautics and Space Administration.

Scientists first proposed what became Gravity Probe B in 1959, a year after the launch of the first American satellite and the creation of NASA. Over the decades, it weathered more than a half- dozen attempts at cancellation amid concerns over cost overruns and technical hurdles.

The Earth-orbiting satellite was built to test elements of Einstein’s theory of general relativity – namely, predictions about the nature of space and time, and how the rotating Earth warps and twists the fabric that combines the two.

As the probe orbits 400 miles above the Earth’s two magnetic poles, the subtle movements of its gyroscopes will measure how space and time are “warped” by the orbit of the planet.

Gravity Probe B will test two parts of what Einstein theorized in 1916: first, that the mass of an object, such as the Earth, causes space to curve around it; second, that its rotation slowly drags space and time with it, a theoretical effect that has never been seen.

The mission is widely expected to prove Einstein right, producing what one NASA official called a “ho-hum” result.

On the Internet: http://einstein.stanford.edu