Aperture: A Precise Extremely large Reflective Telescope Using Re-configurable Elements

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Two NASA NIAC projects for improving space telescopes.

1. Aperture: A Precise Extremely large Reflective Telescope Using Re-configurable Elements

Northwestern University, teamed with the University of Illinois (UIUC), proposes to develop a game changing technology for large deployable optical quality mirrors. The innovation combines the concept of a flying magnetic write head with a magnetic smart material that coats the back of the mirror. Northwestern Univ. will work on the materials and shaping the mirror with a magnetic field. UIUC will work on coupling the deployment design to a flying magnetic write head design. Deployable and deformable reflecting membrane mirror have been worked on in the past, but so far the ability to provide post deployment figure corrections to the level of λ / 20 has eluded the space community. The Phase I NIAC proposal will identify possible solutions to the main problems, such that a Phase II will take the program to TRL 3 or beyond. Some of the hurdles will be coating in such a way that the coatings (front and back) do not distort the mirror beyond our ability to correct. Another hurdle will be ensuring that the corrected mirror retains its shape for significantly long periods of time thereby minimizing the frequency of routine mirror maintenance.

2. Thin-Film Broadband Large Area Imaging System

Fabrication of telescopes, even of relatively modest size requires uniquely complex technology and resources available only to large and specialized institutions. This monopoly is about to be challenged with dramatic cost reduction due to the advent of waveplate lenses and mirrors pioneered by BEAM Co. The objective of the proposed study is to develop concepts for applying diffractive waveplate technology to NASA observation and imaging missions including exoplanet detection. This technology employs “geometric phase” in focusing electromagnetic radiation. The system concept to be developed will comprise a thin-film, nearly weightless broadband diffractive waveplate lens that provides angular resolution and light collection capabilities needed for such missions while allowing aperture sizes to be expanded to levels prohibited by technology or cost considerations for any other currently known concept. Chromatic aberration correction techniques previously developed by us for laser communication applications may be extended to broadband imaging with submicroradian angular resolution. The proposed concept will lead to a new and promising design approach for very large aperture space telescopes making them inexpensively available for accomplishing future NASA missions.