‘Free fall’ produces a change in the force, i.e. acceleration, of gravity as perceived in {TAIL ~ the frame} of reference in which {HEAD ~ the data storage device} is at rest 
‘ Free fall ’ produces a change in the force , i.e. acceleration , of gravity as perceived in { TAIL ~ the frame } of reference in which { HEAD ~ the data storage device } is at rest
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH REL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH