Measurements of droplet size, velocity, and liquid flux were made in sprays produced by a coaxial airblast atomizer using a phase Doppler anemometer. The atomizer comprised a liquid jet with an exit diameter varied between 1.1-2.3 mm, positioned in the center of a gaseous annular stream. The characteristics of the preburner sprays of the main engine of the Space Shuttle were simulated by using water and air, replacing liquid oxygen and hydrogen, respectively. The sprays covered a range of Weber numbers at the exit of the nozzle from 200 to 3500, of gas-to-liquid momentum ratio from 2 to 110, velocity ratio from 10 to 85, mass flow rate ratio from 0.2 to 1.3, liquid jet Reynolds numbers from 1 x 104 to 5.5 x 104, and gaseous jet Reynolds numbers from 9 x 10* to 1.9 x 10s. Reduction of the diameter of the liquid tube was found to improve the atomization and reduce the width of sprays with similar gas-to-liquid velocity ratios. The presence of a converging nozzle at the exit of the gaseous jet improved the atomization and increased the rate of spread of sprays with a gas-to-liquid velocity ratio up to around 50, but had no effect for higher velocity ratios. Recess of the liquid tube by two and three liquid tube diameters increased the rate of spread of the sprays and reduced the atomization for the straight and converging gaseous jet exit nozzle.