Apollo 8 launched on December 21, 1968, and was the second crewed spaceflight mission flown in the United States Apollo space program after Apollo7, which stayed in Earth orbit.
ɐpˈɑːloʊ ˈeɪt lˈɑːntʃt ˌɔn dᵻsˈɛmbɚ twˈɛnti wˈʌn, nˈaɪntiːnhˈʌndɹɪd sˈɪksti ˈeɪt, ænd wʌzðə sˈɛkənd kɹˈuːd spˈeɪsflaɪt mˈɪʃən flˈoʊn ɪnðə juːnˈaɪɾᵻd stˈeɪts ɐpˈɑːloʊ spˈeɪs pɹˈoʊɡɹæm ˈæftɚɹ ɐpˈɑːloʊ sˈɛvən, wˌɪtʃ stˈeɪd ɪn ˈɜːθ ˈɔːɹbɪt.