Three copies of a report entitled 'The Vibration Characteristics of the CHASE Mountings and Structure, An Estimation of Any Thermal Mis-Alignment and Cruciform Loads Spacelab Mission II Experiment 9' relating to the work undertaken to ensure that the instrument met the NASA requirement that no part of it had a resonant frequency below 35Hz. One copy of these reports contains alterations to the text that have been made after typing.