▁were ▁located ▁in ▁two ▁sem ic irc ular ▁st rak es ▁originally ▁thought ▁necessary ▁to ▁help ▁stabil ize ▁the ▁C M ▁during ▁re entry . ▁However , ▁the ▁un cre wed ▁re entry ▁tests ▁proved ▁these ▁to ▁be ▁unnecessary ▁for ▁stability , ▁and ▁also ▁aer od ynam ically ▁in effect ive ▁at ▁high ▁sim ulated ▁lun ar ▁re entry ▁spe eds . ▁Therefore , ▁the ▁st rak es ▁were ▁removed ▁from ▁Block ▁II ▁and ▁the ▁anten nas ▁were ▁moved ▁to ▁the ▁service ▁module . ▁ ▁The ▁Block ▁I ▁C M / SM ▁um bil ical ▁conne ctor ▁was ▁smaller ▁than ▁on ▁Block ▁II , ▁located ▁near ▁the ▁crew ▁h atch ▁instead ▁of ▁nearly ▁ 1 8 0 ▁degrees ▁away ▁from ▁it . ▁The ▁separation ▁point ▁was ▁between ▁the ▁modules , ▁instead ▁of ▁the ▁larger ▁h ing ed ▁arm ▁mounted ▁on ▁the ▁service ▁module , ▁separ ating ▁at ▁the ▁C M ▁side wall ▁on ▁Block ▁II . ▁ ▁The ▁two ▁negative ▁pitch ▁R CS ▁engines ▁located ▁in ▁the ▁forward ▁compart ment ▁were ▁arranged ▁vert ically ▁on ▁Block ▁I , ▁and ▁hor izont ally ▁on ▁Block ▁II . ▁ ▁Service ▁module ▁▁ ▁On ▁the ▁Apol lo ▁ 6 ▁un cre wed ▁Block ▁I ▁flight , ▁the ▁SM ▁was ▁painted ▁white ▁to ▁match ▁the ▁command ▁module ' s ▁appearance . ▁On ▁Apol lo ▁ 1 , ▁Apol lo ▁ 4 , ▁and ▁all ▁the ▁Block ▁II ▁space craft , ▁the ▁SM ▁walls ▁were ▁left ▁un p aint ed ▁except ▁for ▁the ▁E PS ▁and ▁E CS