A Mirror Transport Mechanism for Use at Cryogenic Temperatures

This report describes the Mirror Transport Mechanism (MTM), which supports a pair of dihedral mirrors and moves them in a very smooth and uniform scanning motion normal to a beamsplitter. Each scan is followed by a quick flyback and repeat. Included in the report will be material selection, design, and testing of all major components of the MTM in order to meet the stringent performance requirements under cryogenic conditions and survive the launch environment of the shuttle. Areas to be discussed in detail will be those in which failures or performance anomalies occurred and their solutions. Typically, this will include (but not to be limited to) flex pivot failures during vibration testing, excessive dihedral platform sag under one "g" operation, electronic and fiber optic characteristics, and tolerancing considerations. As of this writing, development of the mechanism has reached the final phase of thermal and vibration qualification. Environmental testing of the complete FIRAS (Far Infrared Absolute Spectrophotometer) experiment is just beginning.