▁used ▁for ▁the ▁Apol lo ▁program , ▁which ▁land ed ▁astr onaut s ▁on ▁the ▁Moon ▁between ▁ 1 9 6 9 ▁and ▁ 1 9 7 2 . ▁The ▁C SM ▁function ed ▁as ▁a ▁mother ▁ship , ▁which ▁carried ▁a ▁crew ▁of ▁three ▁astr onaut s ▁and ▁the ▁second ▁Apol lo ▁space craft , ▁the ▁Apol lo ▁L un ar ▁Module , ▁to ▁lun ar ▁orbit , ▁and ▁brought ▁the ▁astr onaut s ▁back ▁to ▁Earth . ▁It ▁consisted ▁of ▁two ▁parts : ▁the ▁con ical ▁command ▁module , ▁a ▁cabin ▁that ▁hous ed ▁the ▁crew ▁and ▁carried ▁equipment ▁needed ▁for ▁atmos pher ic ▁re entry ▁and ▁spl ash down ; ▁and ▁the ▁cyl ind rical ▁service ▁module ▁which ▁provided ▁prop ulsion , ▁elect rical ▁power ▁and ▁storage ▁for ▁various ▁consum ables ▁required ▁during ▁a ▁mission . ▁An ▁um bil ical ▁connection ▁transferred ▁power ▁and ▁consum ables ▁between ▁the ▁two ▁modules . ▁Just ▁before ▁re entry ▁of ▁the ▁command ▁module ▁on ▁the ▁return ▁home , ▁the ▁um bil ical ▁connection ▁was ▁sever ed ▁and ▁the ▁service ▁module ▁was ▁cast ▁off ▁and ▁allowed ▁to ▁burn ▁up ▁in ▁the ▁atmosphere . ▁ ▁The ▁C SM ▁was ▁developed ▁and ▁built ▁for ▁NASA ▁by ▁North ▁American ▁A viation ▁starting ▁in ▁November ▁ 1 9 6 1 . ▁It ▁was ▁initially ▁designed ▁to ▁land ▁on ▁the ▁Moon ▁at op ▁a ▁landing ▁ro cket ▁stage ▁and ▁return ▁all ▁three ▁astr onaut s ▁on ▁a ▁direct - as cent ▁mission , ▁which ▁would ▁not ▁use ▁a ▁separate ▁lun