. ▁ ▁This ▁was ▁equivalent ▁to ▁about ▁ 6 0 0 m ▁of ▁accuracy ▁over ▁the ▁V 2 ▁ 1 5 0 0 m / s ▁speed ▁and ▁ 3 2 0 km ▁flight . ▁ ▁Since ▁the ▁number ▁of ▁sh aft ▁rot ations ▁represented ▁speed , ▁a ▁Cam ▁Switch ▁was ▁used ▁to ▁initi ate ▁miss ile ▁control ▁sequences ▁such ▁as ▁engine ▁thro tt le - down ▁and ▁shut - off . ▁▁▁ ▁P IG A ▁acceler om eters ▁mounted ▁in ▁the ▁A IR S ▁( Ad vanced ▁In ert ial ▁Reference ▁S phere ) ▁are ▁part ▁of ▁most ▁accurate ▁in ert ial ▁navigation ▁( IN S ) ▁developed ▁for ▁the ▁M X ▁Miss ile . ▁▁ ▁The ▁IN S ▁dr ift ▁rates ▁are ▁less ▁than ▁ 1 . 5 ▁x ▁ 1 0 − 5 ▁degrees ▁per ▁hour ▁of ▁operation , ▁about ▁ 8 . 5 m ▁per ▁hour ▁with ▁the ▁overall ▁accuracy ▁of ▁the ▁miss ile ▁affected ▁more ▁by ▁defect s ▁in ▁the ▁gravit ational ▁maps . ▁ ▁A ▁recovered ▁M MI A ▁acceler ometer ▁from ▁an ▁un expl oded ▁V 2 ▁was ▁presented ▁to ▁Dr ▁Charles ▁St ark ▁Dra per ▁of ▁the ▁United ▁States ' s ▁M IT ▁instrument ation ▁lab ▁who ▁had ▁been ▁developing ▁the ▁basis ▁of ▁in ert ial ▁navigation ▁for ▁aircraft ▁by ▁initially ▁concentr ating ▁efforts ▁on ▁ach ieving ▁extremely ▁low ▁dr ift ▁rate ▁gy ro scop es ▁known ▁as ▁a ▁flo ated ▁integr ating ▁gy ros cope . ▁ ▁Dra per ▁combined ▁ideas ▁from ▁his ▁integr