Manufacturing grazing incidence x-ray mirrors costs between $4 to $6 million per square meter of optical surface area. To reduce the cost of making x-ray mirrors, NASA is seeking manufacturing solutions to aid in cost reduction factors of 5 to 50 times. One cost driver is the mandrel-based polishing process that impacts both the inside and outside surfaces of an X-ray mirror shell. Current shells are created through a replication process utilizing an aluminum mandrel. OptiPro is proposing to enhance process solutions to reduce the cost required for polishing both the mandrel and the outside shell surface by maintaining a constant force during polishing, developing new polishing tools, and optimizing the polishing algorithm. The target platform for these improvements will be on OptiPro's bridge polishing platform that has a rotary A-axis to spin the part and a combination polishing head that can handle a range of polishing tools while making it easier to rapidly switch between tools. These improvements will be directly applicable to the polishing being done at Marshall Space Flight Center on various equipment including OptiPro's 6-axis UltraForm Finishing platform.
OptiPro Systems will focus on the process evaluation and the interface between the polisher and metrology platform to provide a cost effective deterministic solution. A new force-measurement system will also be evaluated for its potential to provide in-situ process feedback during polishing. New polishing tools will be designed, built, and tested along with the pellet tool developed at MSFC and other commercially available polishing tools. Algorithm changes will be required for polishing the surfaces of the x-ray mirror mandrel and shells and will be demonstrated on a surrogate aluminum mandrel. The results of this Phase I effort will enhance the fabrication at MSFC and provide the concept design requirements of a meter class finishing platform which could be built in a Phase II effort.
The proposed system will benefit all projects using x-ray shells and mandrels, both cylindrical and segments, that fit within the working envelope of the proposed machine. Missions including IXPE, LYNX, and ESCAPE will be among those that would benefit from the technology being developed. These improvements will be applicable to polishing being done at Marshall Space Flight Center on various equipment including OptiPro's 6-axis UltraForm Finishing platform and polishing being done at Goddard Space Flight Center.
The proposed polishing system and hardware improvements would benefit all types of part geometries including the following: