ot ons , ▁were ▁deployed ▁on ▁these ▁miss iles ▁starting ▁in ▁ 1 9 5 8 ▁and ▁finally ▁retired ▁in ▁ 1 9 8 9 . ▁▁ 2 , 5 5 0 ▁of ▁these ▁models ▁were ▁produced . ▁The ▁ 2 0   kt ▁version ▁of ▁the ▁W - 3 1 ▁was ▁sole ly ▁used ▁in ▁the ▁N ike ▁Her cules ▁system . ▁ ▁A ▁similar ▁variant , ▁the ▁X W - 3 7 , ▁was ▁a ▁high ▁yield ▁version ▁of ▁the ▁X W - 3 1 . ▁Development ▁started ▁in ▁January ▁ 1 9 5 6 . ▁Three ▁months ▁later , ▁the ▁X W - 3 1 ▁was ▁red es ign ated ▁X W - 3 1 Y 1 ▁( for ▁yield ▁ 1 ) ▁and ▁the ▁X W - 3 7 ▁design ation ▁was ▁changed ▁to ▁X W - 3 1 Y 2 ▁( for ▁yield ▁ 2 ). ▁ ▁M GR - 1 ▁Hon est ▁John ▁ro cket ▁ ▁The ▁Hon est ▁John ▁was ▁a ▁short - range ▁surface - to - sur face ▁tact ical ▁ball istic ▁ro cket ▁used ▁by ▁the ▁US ▁Army . ▁ ▁Three ▁yield ▁variants , ▁also ▁apparently ▁ 2 , ▁ 2 0 ▁and ▁ 4 0 ▁kil ot ons , ▁were ▁deployed ▁on ▁Hon est ▁John ▁miss iles ▁from ▁ 1 9 5 9 ▁to ▁ 1 9 8 7 . ▁A ▁total ▁of ▁ 1 , 6 5 0 ▁Hon est ▁John ▁W 3 1 ▁war head s ▁were ▁produced . ▁