ters , ▁and ▁by ▁the ▁late ▁ 1 9 7 0 s ▁was ▁known ▁as ▁the ▁Bas eline ▁Terminal ▁Def ense ▁System . ▁ ▁But ▁Carter ' s ▁choice ▁had ▁only ▁just ▁been ▁made ▁when ▁Ron ald ▁Re agan ▁won ▁the ▁presiden cy ▁and ▁set ▁about ▁re - ex am ining ▁the ▁M X ▁plans . ▁In ▁October ▁ 1 9 8 1 ▁they ▁announced ▁M X ▁deployment ▁would ▁be ▁sp ed ▁up , ▁can cell ing ▁the ▁M PS ▁bas ing ▁and ▁recomm ending ▁the ▁miss iles ▁tempor arily ▁be ▁placed ▁in ▁existing ▁T itan ▁II ▁and ▁Min ut eman ▁sil os ▁until ▁a ▁final ▁solution ▁could ▁be ▁decided ▁on . ▁Work ▁on ▁Lo AD S ▁continued , ▁in ▁and ▁June ▁ 1 9 8 2 ▁was ▁renamed ▁S entry . ▁The ▁program ▁was ▁told ▁to ▁be ▁prepared ▁to ▁go ▁into ▁production ▁on ▁short ▁notice . ▁ ▁Work ▁on ▁the ▁high - alt itude ▁non - n uc lear ▁concept ▁was ▁also ▁on going ▁through ▁this ▁period , ▁and ▁would ▁ultimately ▁be ▁demonstrated ▁in ▁ 1 9 8 4 ' s ▁Hom ing ▁Over lay ▁Ex periment . ▁ ▁Can cellation ▁ ▁On ▁ 2 2 ▁November ▁ 1 9 8 2 , ▁Re agan ▁held ▁another ▁conference ▁on ▁the ▁M X ▁issue . ▁He ▁announced ▁that ▁M PS ▁was ▁being ▁abandoned ▁and ▁replaced ▁by ▁the ▁D ense ▁Pack ▁concept . ▁This ▁would ▁consist ▁of ▁new ▁super - hard ened ▁sil os ▁that ▁could ▁with stand ▁very ▁close ▁hits , ▁pack ed