While at Convair , he designed the D - 1 Centaur , the world 's first upper - stage - booster that used liquid hydrogen and oxygen .
Upon leaving government service Ehricke worked at Bell Aircraft , and then for Convair in 1952 .
While at Convair , Ehricke designed the D - 1 Centaur , the world 's first upper - stage - booster that used liquid hydrogen and oxygen .
Upon leaving government service Ehricke worked at Bell Aircraft , and then for Convair in 1952 .