On July 4 , 1943 , he received a telephone call from Apollo M.O. Smith .
On July 4 , 1943 , he was offered a position at Aerojet. Smith was the chief engineer at Aerojet and an expert in fluid mechanics .
On July 4 , 1943 , he received a telephone call from Apollo M.O. Smith and was offered a position at Aerojet. Smith was the chief engineer at Aerojet and an expert in fluid mechanics .