With Help From Delta II Rocket

After more than 40 years in the making and a day-long launch delay, NASA Tuesday launched its Gravity Probe B, designed to test the more arcane of Albert Einstein's relativity theories.

The 6,800 pound probe, built at a cost of $750 million, lifted off from Vandenburg AFB (CA) at around 1:00 pm EDT, aboard a Boeing Delta II rocket. That ended the longest-ever satellite development program NASA has ever seen. It was first proposed in 1959 and has survived several attempts to kill it since.

The experiment, designed by scientists at Stanford University (CA), revolves around four spheres, about the size of ping-pong balls. They are the most perfect spheres ever created by man -- advertised as accurate to within a diametrical variance of 40 atoms.

If Einstein was right, then once the balls are set to spinning in orbit, their alignment should shift in very small -- but measurable -- ways. In 1916, Einstein predicted that massive bodies in space can warp the space-time continuum.

It won't be the first time that scientists have measure the warping. But the Gravity B Probe will not only measure that effect, it will also test another theory called frame-dragging. That's a twisting effect on time and space.

FMI: www.einstein.stanford.edu