The "F" Mission would test the CSM and LM in lunar orbit, and the "G" mission would be the finale, the Moon landing.
ðə "ˈɛf" mˈɪʃən wʊd tˈɛst ðə sˌiːˌɛsˈɛm ænd ˌɛlˈɛm ɪn lˈuːnɚɹ ˈɔːɹbɪt, ænd ðə "dʒˈiː" mˈɪʃən wʊd biː ðə fɪnˈɑːli, ðə mˈuːn lˈændɪŋ.