On June 29, 1974 at 15:14 LST a rocket-borne cryogenic neutral gas mass spectrometer was flown above Wallops Island as part of the NASA/AFCRL ALADDIN 74 program. The altitude profiles of the signals obtained from argon between 90 and 200 km and ozone betwenn 90 and 110 km are presented. From a comparison of Ar and O3 signals, the mixing ratio for O3 in the atmosphere is shown to be 10-6 or slightly less in the 90--100 km range. At 110 km the mixing ratio drops to around 10-7.