The earliest astronauts for both the US and the USSR tended to be jet fighter pilots, and were often test pilots.
ðɪ ˈɜːlɪɪst ˈæstɹənˌɔːts fɔːɹ bˈoʊθ ðə jˌuːˈɛs ænd ðə jˌuːˌɛsˌɛsˈɑːɹ tˈɛndᵻd təbi dʒˈɛt fˈaɪɾɚ pˈaɪləts, ænd wɜːɹ ˈɔfən tˈɛst pˈaɪləts.