Volume mixing ratio profiles of ethane (C2H6) in the lower stratosphere and upper troposphere and acetylene (C2H2) in the upper troposphere have been deduced from analysis of 0.01-cm-1-resolution infrared solar absorption spectra recorded between 25¿ N and 31¿ N latitude. The spectral data were obtained by the ATMOS (Atmospheric Trace Molecule Spectroscopy) Fourier transform spectrometer during the Spacelab 3 shuttle mission on April 30 to May 1, 1985. The investigation was based on nonlinear least squares curve fitting of the &ngr;7 band PQ3 subbranch near 2976.8 cm-1 and the &ngr;9 band RQ0 subbranch near 822.3 cm-1 for C2H6 and of the &ngr;5 band R10 and R19 lines of C2H2 at 755.0056 and 776.0818 cm-1, respectively. Improvements in the spectroscopic data base for the regions containing these absorption features are reported. The C2H6 results indicate a nearly constant volume mixing ratio of 0.97 parts per billion by volume (ppbv) between 6 and 12 km and a decline to 0.1--0.2 ppbv at 18 km altitude. Measured C2H2 mixing ratios are 0.070--0.092 ppbv between 7.7 and 12.6 km and 0.02 ppbv at 15.1 km. An upper limit of 0.02 ppbv is obtained for the average C2H2 mixing ratio above 16.6 km. The retrieved profiles are compared with previous measurements and model calculations. ¿ American Geophysical Union 1987