ðɪs ɪz mˈoʊstli dˈʌn ɪn tˈiː θˈɜːɾi ˈeɪt dʒˈɛt ˈɛɹkɹæft ˌaʊɾəv ˈɛlɪŋtən fˈiːld, dˈuː tʊ ɪts pɹɑːksˈɪmᵻɾi tə ðə dʒˈɑːnsən spˈeɪs sˈɛntɚ.
This is mostly done in T-38 jet aircraft out of Ellington Field, due to its proximity to the Johnson Space Center.