Of eight X-15 pilots who exceeded  in altitude, only one, Joseph A. Walker, exceeded 100 kilometers (about 62.1 miles) and he did it two times, becoming the first person in space twice.
ʌv ˈeɪt ˈɛks fˈɪftiːn pˈaɪləts hˌuː ɛksˈiːdᵻd ɪn ˈæltɪtˌuːd, ˈoʊnli wˌʌn, dʒˈoʊsəf ˈeɪ. wˈɔːkɚ, ɛksˈiːdᵻd wˈʌnhˈʌndɹɪd kɪlˈɑːmɪɾɚz ɐbˌaʊt sˈɪksti tˈuː.wˈʌn mˈaɪlz ænd hiː dˈɪd ɪt tˈuː tˈaɪmz, bᵻkˈʌmɪŋ ðə fˈɜːst pˈɜːsən ɪn spˈeɪs twˈaɪs.