In this paper we investigate the form and dynamics of shock acoustic waves (SAW) generated during the rocket Proton launching from the Baikonur cosmodrome in 1998 and 1999. In spite of the difference of geophysical conditions, the ionospheric response for all launchings has a period of about 300 s and the amplitude exceeding background fluctuations under quiet and moderate geomagnetic conditions by factors of 2 to 5 as a minimum. The angle of elevation of the SAW wave vector varies from 45 • to

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... 60 • , and the SAW phase velocity (900-1200 m/s) approaches the sound velocity at heights of the ionospheric F region maximum. The position of the SAW source, inferred by neglecting refraction corrections, corresponds to the segment of the rockets path at a distance no less than 700-900 km from the launch pad, which is consistent with the estimated delay time of SAW source triggering (250-300 s).