The Ascent Air Data System for the Space Shuttle

The Ascent Air Data System (AADS) consists of a biconic spike probe on the nose of the Space Shuttle External Tank. The final configuration of the AADS was selected on the basis of pressure measurement accuracy and simplification of the configuration. Wind tunnel calibrations were formulated to convert the 30 deg/10 deg spike measured pressures to the desired air data parameters for postflight analyses. Estimates of the system performance show that in general the user requirements for angle of attack and sideslip, and dynamic pressure are met or only slightly exceeded by the estimated errors.