By Broward Liston

Almost a century after Albert Einstein began writing about relativity, NASA is poised to launch a mission 45 years in the making to put a little known tenet of his general relativity theory to its first test.

The Gravity Probe B satellite is the bland name given to one of the most precise scientific instruments ever built. But the project`s $700 million price-tag adds glamour, as does its long history, surviving the Congressional budget ax seven times.

Lift-off of the Boeing Co. Delta 2 rocket carrying the probe is scheduled for Monday at 1:01 p.m. EDT from the rocket range at California`s Vandenberg Air Force Base.

With four near-perfect spheres -- the roundest objects ever made, according to NASA -- the probe will try to show whether the Earth, which is known to warp both time and space with its mass, also twists them like tornado winds as it rotates.

That was Einstein`s prediction in his theory of general relativity. He had already, in 1905, answered many of the most important questions about mass, energy and the speed of light with his theory of special relativity.

INSIGHTS INTO TIME AND SPACE

By 1915, he was applying those insights to time and space. His theories showed how massive objects -- planets, stars, black holes -- warp time and space, slowing down clocks and sucking nearby objects toward them.

That is why an apple falls from a tree and speeding planets do not escape the sun.

Einstein also argued that the space-time continuum was twisted and dragged by the spinning of massive objects, an effect known as `frame dragging.`

`We`ve seen two of the three aspects of warped space-time. We`ve seen the warping of space and the warping of time. We have never seen, in any clean way, the dragging of space into motion,` said Kip Thorne, who holds the Richard Feynman chair in theoretical physics at the California Institute of Technology.