Apollo6 had suffered several major problems during its April 1968 flight, including severe pogo oscillation during its first stage, two second-stage engine failures, and a third stage that failed to reignite in orbit.
ɐpˈɑːloʊ sˈɪks hæd sˈʌfɚd sˈɛvɹəl mˈeɪdʒɚ pɹˈɑːbləmz dˈʊɹɹɪŋ ɪts ˈeɪpɹəl nˈaɪntiːnhˈʌndɹɪd sˈɪksti ˈeɪt flˈaɪt, ɪŋklˈuːdɪŋ sᵻvˈɪɹ pˈoʊɡoʊ ˌɑːsɪlˈeɪʃən dˈʊɹɹɪŋ ɪts fˈɜːst stˈeɪdʒ, tˈuː sˈɛkəndstˈeɪdʒ ˈɛndʒɪn fˈeɪlɪɹz, ænd ɐ θˈɜːd stˈeɪdʒ ðæt fˈeɪld tə ɹˌiːɪɡnˈaɪt ɪn ˈɔːɹbɪt.