NASA launches satellite to test Einstein predictions

Tuesday, April 20th 2004, 12:00 am

By: News On 6

LOS ANGELES (AP) _ NASA on Tuesday launched a $750 million satellite conceived during the Eisenhower administration to test 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 at 9:57 a.m. PDT. The launch, aboard a Delta II rocket, came one day after officials scrubbed an earlier attempt.

The satellite was to separate from the rocket and begin its 18-month mission 75 minutes after liftoff.

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 two of Einstein's predictions about the nature of space and time, and how the rotating Earth warps and twists the fabric that combines the two.

Scientists at Stanford University designed the spacecraft around four spheres of quartz the size of ping-pong balls. They are the most perfect spheres ever made.

Theory predicts that by lining up the satellite in space with a distant star and setting the balls spinning, their alignment should shift off kilter in small but measurable amounts in response to the mass and rotation of the Earth.