•High frequency modulation of expected signal  (reduction of  "1/f" electronic and mechanical noise; satellite designed for rapid spin, easy attitude stabilization). 
•Mechanical suspensions ensure electric grounding, hence eliminate charging effects passively (low stiffness ensured by weightlessness Þ high sensitivity)
•Instrument inherently differential: test bodies coupled by the read out and by very weak suspensions like in an ordinary beam balance for higher sensitivity to differential forces
GG: main novelties and advantages (I)