Can we measure it?einstein.stanford.edu

• This force has never been detected in the laboratory, but has been predicted by Einstein and other researchers.

 
• Onboard computers check, very precisely, any variations in the spin of the four gyros at the heart of the satelite.  The slightest wobble will be detected as the spacecraft orbits our magnetic poles. 

 
• Data will reveal how the Earth warps space/time by its presence,  more importantly, how the earths rotation 'drags' space and time around with it.