Hubble Space Telescope Backup Mirror

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    Hubble Space Telescope Backup Mirror

    This is the backup primary mirror for the Hubble Space Telescope manufactured by the Eastman Kodak Company. The blank for this mirror was fabricated by the Corning Glass Works using their high silicon Ultra Low Expansion Glass (ULE 7971). It consists of two 1-inch glass disks fused to the faces of a thin square eggcrate-like support structure.

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    CCO - Creative Commons (CC0 1.0)

    This media is in the public domain (free of copyright restrictions). You can copy, modify, and distribute this work without contacting the Smithsonian. For more information, visit the Smithsonian's Terms of Use page.

    IIIF provides researchers rich metadata and image viewing options for comparison of works across cultural heritage collections. More - https://iiif.si.edu

    View Manifest

    View in Mirador Viewer

    Hubble Space Telescope Backup Mirror

    This is the backup primary mirror for the Hubble Space Telescope manufactured by the Eastman Kodak Company. The blank for this mirror was fabricated by the Corning Glass Works using their high silicon Ultra Low Expansion Glass (ULE 7971). It consists of two 1-inch glass disks fused to the faces of a thin square eggcrate-like support structure.

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    Hubble Space Telescope Backup Mirror

    Primary backup mirror for the Hubble Space Telescope.

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    Hubble Space Telescope Backup Mirror

    Backup primary mirror for the Hubble Space Telescope.

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Display Status:

This object is on display in the Explore the Universe exhibition at the National Air and Space Museum in Washington, DC.

This is the backup primary mirror for the Hubble Space Telescope manufactured by the Eastman Kodak Company. The blank for this mirror was fabricated by the Corning Glass Works using their high silicon Ultra Low Expansion Glass (ULE 7971). It consists of two 1-inch glass disks fused to the faces of a thin square eggcrate-like support structure. This support structure creates a mirror that weighs about one-fifth that of a solid piece of the same size but retains required rigidity and stability characteristics. The blank mirror was sent to the Kodak Apparatus Division located in Rochester, NY, when they won a NASA contract to create the back-up optical mirror. Kodak ground the mirror surface into the proper concave shape and then polished it to successively finer tolerances using computer-assisted testing routines. The finished mirror was tested and verified by Kodak to meet the strict optical tolerances prescribed by NASA. It was left un-aluminized mirror and delivered to the Perkin-Elmer Corporation in Danbury Connecticut, the prime contractor for the flight mirror, and was stored there until the end of 2000, at which time NASA determined that its value as a display object was greater than its potential value as a telescope mirror. It was then transferred from NASA to NASM by Raytheon, who absorbed Perkin-Elmer.