The probe, which launched in 2004, was designed to test the effect Earth's gravity has on the space-time around it. According to Einstein, the Earth warps its local space-time like a bowling ball ...

Nasa's Gravity Probe B has produced remarkable new confirmation of some key predictions by Albert Einstein. The satellite's observations show the massive body of the Earth is very subtly warping ...

After many delays and false starts, Gravity Probe B was finally launched in April 2004. It tested both effects with four gyroscopes consisting of spinning quartz spheres coated with the metal niobium.