When Gravity Probe B was first proposed by NASA, Dwight D.
Eisenhower was president. Cuba was still considered a friendly
country and Vietnam was a place few Americans could point to on a
map. Manned space flight was still an unrealized dream.
Now, 45-years later, Gravity Probe B is finally being prepared for
lift-off at Vandenberg AFB (CA). It's mission: test two linchpin
theories first proposed by Albert Einstein. In 1916, Einstein
figured a planet like Earth could actually mold and twist the
fabric of space and time. Think of a lead weight resting in the
middle of a soft mattress and you'll get an idea of what he had in
mind. That very effect, he proposed, is directly responsible for
gravity.