ating ▁gy ro scop es , ▁which ▁were ▁mounted ▁in ▁can s ▁that ▁flo ated ▁in ▁flu ids ▁that ▁were ▁held ▁in ▁place ▁by ▁jewe led ▁bear ings , ▁ ▁with ▁the ▁recovered ▁V 2 ▁acceler ometer ▁by ▁floating ▁the ▁p end ul um - gy ros cope ▁portion . ▁The ▁more ▁generic ▁name ▁of ▁P IG A ▁was ▁suggested ▁by ▁Dr ▁Dra per ▁due ▁to ▁the ▁addition ▁of ▁various ▁ref in ements ▁such ▁as ▁elect romagnet ic ▁or ▁optical ▁sens ing ▁of ▁p end ul um ▁position . ▁Such ▁acceler om eters ▁were ▁used ▁in ▁the ▁T itan ▁II ▁and ▁Pol aris ▁Systems ▁and ▁Min ut eman ▁systems . ▁ ▁At ▁the ▁Red stone ▁Ar sen al ▁and ▁the ▁ad jo ining ▁Marshall ▁Space ▁Fl ight ▁Center , ▁near ▁Hun ts ville ▁Alabama ▁the ▁cont ing ent ▁of ▁ex - G erman ▁ro cket ▁scient ists ▁which ▁had ▁been ▁brought ▁into ▁the ▁United ▁States ▁under ▁Operation ▁Pap erc lip , ▁including ▁Dr ▁Mu eller , ▁ ▁continued ▁to ▁ref ine ▁their ▁original ▁instruments ▁in ▁conj unction ▁with ▁American ▁engine ers ▁and ▁scient ists . ▁ ▁At ▁the ▁suggestion ▁of ▁Dr ▁Mu eller , ▁the ▁techn ically ▁difficult ▁task ▁of ▁replacing ▁the ▁original ▁ball ▁bear ings ▁with ▁g ase ous ▁bear ings ▁was ▁achieved . ▁ ▁Initial ly ▁com pressed ▁nit ro gen ▁was ▁used ▁but ▁later ▁flu or oc ar b ons ▁which ▁had ▁the ▁advantage ▁of ▁being ▁rec y cl able ▁on ▁board ▁the ▁miss ile ▁or ▁aircraft ▁during ▁extended ▁waiting