[2025] Metrology for efficient assembly, integration, and testing of space telescopes

J. H. Burge, E. LaVilla, C. K. Merle, and T. Steele “Metrology for efficient assembly, integration, and testing of space telescopes”, Proc. SPIE 13624, Astronomical Optics: Design, Manufacture, and Test of Space and Ground Systems V, 136240P (18 September 2025)

Abstract:

The rapid expansion of space-based optical systems for earth observation, communications, defense, and science applications has created an unprecedented demand for precision telescope manufacturing at production volumes. Traditional alignment, integration, and testing methodologies, while effective for one-off specialized systems, do not scale well. For manufacturing a single system, considerable effort goes into the design of the system that is assembled by experts. For production, investment must be made in tooling and procedures so the manufacturing can be done efficiently by technicians. Much of the work in building optical systems is defined by the metrology – surfaces and alignment are adjusted until they are measured to meet the stringent performance criteria. For efficient production, the measurement systems must be optimized for each critical operation and must be integrated into the manufacturing plan. Some examples are presented that have successfully used computergenerated holograms (CGHs) for space telescope production. The measurement of each of the mirrors is measured using interferometry with CGHs, including calibration for gravity. As the optical components are built into their subassemblies, CGH testing is used to validate alignment and effects of bonding. The critical alignment of the secondary mirror can be accomplished efficiently using the Argus Alignment Method, which uses a CGH to provide simultaneous alignment and wavefront measurements. An additional CGH measures the complete optical system over its field of view and provides definition for the focal plane assembly. In many cases, a final test with a CGH projecting structured light into the system coupled with motion of scan mirrors verifies the image quality all the way to the focal plane.

Link to publication.