▁heat ▁shield ▁design , ▁which ▁was ▁tested ▁on ▁the ▁un cre wed ▁Apol lo ▁ 4 ▁and ▁Apol lo ▁ 6 ▁fl ights , ▁so ▁the ▁first ▁all - up ▁Block ▁II ▁space craft ▁fle w ▁on ▁the ▁first ▁cre wed ▁mission , ▁Apol lo ▁ 7 . ▁ ▁The ▁two ▁blocks ▁were ▁essentially ▁similar ▁in ▁overall ▁dimensions , ▁but ▁several ▁design ▁improvements ▁resulted ▁in ▁weight ▁reduction ▁in ▁Block ▁II . ▁Also , ▁the ▁Block ▁I ▁service ▁module ▁prop ell ant ▁t anks ▁were ▁slightly ▁larger ▁than ▁in ▁Block ▁II . ▁The ▁Apol lo ▁ 1 ▁space craft ▁we ighed ▁approximately ▁, ▁while ▁the ▁Block ▁II ▁Apol lo ▁ 7 ▁we ighed ▁. ▁( Th ese ▁two ▁Earth ▁orb ital ▁craft ▁were ▁l ighter ▁than ▁the ▁craft ▁which ▁later ▁went ▁to ▁the ▁Moon , ▁as ▁they ▁carried ▁prop ell ant ▁in ▁only ▁one ▁set ▁of ▁t anks , ▁and ▁did ▁not ▁carry ▁the ▁high - g ain ▁S - band ▁anten na .) ▁In ▁the ▁specific ations ▁given ▁below , ▁unless ▁otherwise ▁noted , ▁all ▁weights ▁given ▁are ▁for ▁the ▁Block ▁II ▁space craft . ▁ ▁The ▁total ▁cost ▁of ▁the ▁C SM ▁for ▁development ▁and ▁the ▁units ▁produced ▁was ▁$ 3 6 . 9 B ▁in ▁ 2 0 1 6 ▁dollars , ▁adjust ed ▁from ▁a ▁nom inal ▁total ▁of ▁$ 3 . 7 B ▁using ▁the ▁NASA ▁New ▁Start ▁In fl ation ▁Ind ices . ▁ ▁Command ▁module ▁( CM ) ▁▁ ▁The ▁command ▁module ▁was ▁a ▁trunc ated ▁cone