In 1966, Simpson met NASA astronaut Pete Conrad, who introduced Simpson to the Nomex material used in spacesuits for the Apollo program. Around the same time, DuPont also approached the Hinchman company about producing Nomex racing suits. In that year's Indianapolis 500, driver Mel Kenyon wore a Nomex fire suit produced by Hinchman. Later that year, several drivers began testing experimental Nomex suits for Simpson, including F1 drivers Walt Hansgen and Masten Gregory, NASCAR driver Marvin Panch, and SCCA Trans-Am Series driver Bob Tullius. Simpson's company Simpson Performance Products released the first commercial Nomex racing suit, called the "Heat Shield Firesuit", in 1967. The suits were worn by 30 of 33 competitors in the 1967 Indianapolis 500.