The Soviet Union had heavier-lifting carrier rockets, which meant Kennedy needed to choose a goal that was beyond the capacity of the existing generation of rocketry, one where the US and Soviet Union would be starting from a position of equality—something spectacular, even if it could not be justified on military, economic, or scientific grounds.
ðə sˈoʊviət jˈuːniən hæd hˈɛviɚlˈɪftɪŋ kˈæɹiɚ ɹˈɑːkɪts, wˌɪtʃ mˈɛnt kˈɛnədi nˈiːdᵻd tə tʃˈuːz ɐ ɡˈoʊl ðæt wʌz bᵻjˌɔnd ðə kəpˈæsᵻɾi ʌvðɪ ɛɡzˈɪstɪŋ dʒˌɛnɚɹˈeɪʃən ʌv ɹˈɑːkɪtɹi, wˈʌn wˌɛɹ ðə jˌuːˈɛs ænd sˈoʊviət jˈuːniən wʊd biː stˈɑːɹɾɪŋ fɹʌm ɐ pəzˈɪʃən ʌv iːkwˈɔlᵻɾi—sˈʌmθɪŋ spɛktˈækjʊlɚ, ˈiːvən ɪf ɪt kʊd nˌɑːt biː dʒˈʌstᵻfˌaɪd ˌɔn mˈɪlətˌɛɹi, ˌiːkənˈɑːmɪk, ɔːɹ saɪəntˈɪfɪk ɡɹˈaʊndz.