Adaptive Petal Reflector: In-Lab Software Configurable Optical Testing System Metrology and Modal Wavefront...

Area of Science:

• Optical engineering
• Spacecraft instrumentation
• Materials science

Background:

• Development of actively controlled foldable reflectors for CubeSats and small satellites by the European Space Agency (ESA).
• Need for precise metrology of spherical, petal polymer reflectors for large-aperture space telescopes.

Purpose of the Study:

• To address two key metrology challenges in the development of foldable polymer reflectors.
• To validate the Software Configurable Optical Testing System (SCOTS) for surface figure error measurement.
• To develop a method for wavefront error reconstruction of petal reflectors with obstructed areas.

Main Methods:

• Utilizing the Software Configurable Optical Testing System (SCOTS) for initial surface figure error assessment of individual spherical reflectors.
• Employing modal analysis, specifically using vibration modes, to reconstruct wavefront errors for assembled petal reflectors.
• Leveraging common mechanical boundary conditions of petal segments at the central support ring for modal reconstruction.

Main Results:

• SCOTS provides a fast and satisfactory solution for measuring the surface figure error of individual spherical reflectors.
• Wavefront error reconstruction is achieved over the entire surface of the petal reflector, despite partial obscuration by the secondary mirror.
• Modal amplitudes are successfully reconstructed from slope data outside the obstructed regions.

Conclusions:

• The proposed metrology techniques are effective for characterizing foldable polymer reflectors for space applications.
• SCOTS is a viable tool for early-stage quality assessment of reflector components.
• Modal analysis offers a robust solution for wavefront reconstruction in complex optical systems with obstructions.