ett ▁war head ▁and ▁the ▁Special ▁At omic ▁Dem ol ition ▁Mun ition . ▁ ▁In ▁Little ▁F eller ▁II ▁( J uly ▁ 7 ), ▁the ▁war head ▁was ▁susp ended ▁only ▁three ▁feet ▁above ▁the ▁ground ▁and ▁had ▁a ▁yield ▁equivalent ▁to ▁only ▁ 2 2 ▁tons ▁of ▁T NT . ▁In ▁Little ▁F eller ▁I ▁( J uly ▁ 1 7 ), ▁the ▁war head ▁was ▁launched ▁as ▁a ▁Dav y ▁Cro ck ett ▁device ▁from ▁a ▁station ary ▁ 1 5 5 ▁millimeter ▁launch er ▁and ▁set ▁to ▁det on ate ▁between ▁ 2 0 ▁and ▁ 4 0 ▁feet ▁above ▁the ▁ground ▁( 6 - 1 2 ▁meters ) ▁around ▁ 1 . 7 ▁miles ▁( 2 . 7   km ) ▁from ▁the ▁launch ▁point , ▁with ▁a ▁yield ▁of ▁ 1 8 ▁tons . ▁This ▁test ▁was ▁performed ▁in ▁conj unction ▁with ▁Operation ▁I vy ▁Fl ats , ▁a ▁sim ulated ▁military ▁environment , ▁and ▁was ▁observed ▁by ▁Att orney ▁General ▁Robert ▁F . ▁Kennedy ▁and ▁president ial ▁advis er ▁General ▁Max well ▁D . ▁Taylor . ▁ ▁Little ▁F eller ▁I ▁has ▁the ▁additional ▁distinction ▁of ▁being ▁the ▁last ▁near - ground ▁atmos pher ic ▁nuclear ▁det on ation ▁conducted ▁by ▁the ▁United ▁States ▁of ▁America ▁ ▁( the ▁high ▁alt itude ▁ ▁Fish bow l ▁tests ▁concluded ▁in ▁November ▁ 1 9 6 2 ▁with ▁a ▁det on ation ▁at ▁around ▁ 2 1   km ▁alt itude ). ▁ ▁All ▁further ▁tests ▁were