▁instead ▁of ▁the ▁two - pie ce ▁plug ▁h atch ▁used ▁on ▁Block ▁I , ▁in ▁which ▁the ▁inner ▁piece ▁had ▁to ▁be ▁un bol ted ▁and ▁placed ▁inside ▁the ▁cabin ▁in ▁order ▁to ▁enter ▁or ▁exit ▁the ▁space craft ▁( a ▁f law ▁that ▁do omed ▁the ▁Apol lo ▁ 1 ▁crew ). ▁The ▁Block ▁II ▁h atch ▁could ▁be ▁opened ▁quickly ▁in ▁case ▁of ▁an ▁emer gency . ▁( B oth ▁h atch ▁versions ▁were ▁covered ▁with ▁an ▁extra , ▁remov able ▁section ▁of ▁the ▁Bo ost ▁Prote ct ive ▁Cover ▁which ▁surrounded ▁the ▁C M ▁to ▁protect ▁it ▁in ▁case ▁of ▁a ▁launch ▁abort .) ▁ ▁The ▁Block ▁I ▁forward ▁access ▁tunnel ▁was ▁smaller ▁than ▁Block ▁II , ▁and ▁intended ▁only ▁for ▁emer gency ▁crew ▁e gress ▁after ▁spl ash down ▁in ▁case ▁of ▁problems ▁with ▁the ▁main ▁h atch . ▁It ▁was ▁covered ▁by ▁the ▁nose ▁of ▁the ▁forward ▁heat ▁shield ▁during ▁flight . ▁Block ▁II ▁contained ▁a ▁shorter ▁forward ▁heat ▁shield ▁with ▁a ▁flat ▁remov able ▁h atch , ▁beneath ▁a ▁dock ing ▁ring ▁and ▁pro be ▁mechanism ▁which ▁captured ▁and ▁held ▁the ▁L M . ▁ ▁The ▁al umin ized ▁P ET ▁film ▁layer , ▁which ▁gave ▁the ▁Block ▁II ▁heat ▁shield ▁a ▁sh iny ▁mirror ed ▁appearance , ▁was ▁absent ▁on ▁Block ▁I , ▁expos ing ▁the ▁light ▁gray ▁epo xy ▁res in ▁material , ▁which ▁on ▁some ▁fl ights ▁was ▁painted ▁white . ▁ ▁The ▁Block ▁I ▁V H F ▁sc im itar ▁anten nas