Measurements of stray light suppression with mirrors, lenses, and baffle systems from four zodiacal light and one noctilucent cloud space experiments are reported. The method used to derive the total stray light suppression from these measurements is given. The predicted residual stray light intensity of about 10(-11) sr(-1) to 10(-10) sr(-1) corresponds to approximately 1% of the zodiacal light intensity and is confirmed by the available inflight results. Therefore accurate photometry of the zodiacal light is possible from a sunlit rocket or satellite.