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FUSE Mirrors

The FUSE satellite uses light focussed from FOUR SEPARATE MIRRORS to perform its task; it's effectively four telescopes working together! Each of the four mirrors is 39 cm by 35 cm (nearly square) and are ground into "off-axis parabolas" to properly focus their light into the FUSE spectrograph. CLICK HERE to see a diagram showing the positions of the mirrors in the FUSE light path.

Caption: The photo below shows a FUSE flight mirror in a clean room at the JHU Applied Physics Laboratory, mounted in its support structure prior to installation in the telescope. The mirror assemblies were assembled and tested in the clean room facility at JHU/Bloomberg on the Homewood campus. (Photo from April 1998.)

Caption: The photo below shows a FUSE flight mirror after coating with reflective materials but prior to mounting in its support structure or installation in the telescope. (Photo from Fall 1997.)

Caption: The photo below shows a prototype FUSE mirror being inserted into a vacuum tank at NASA Goddard Space Flight Center, where it will be over-coated with reflective materials. Two of the four FUSE mirrors will have coatings of LiF (lithium fluoride) and two will be coated with SiC (silicon carbide.)

This photo shows a FUSE Engineering Test Unit (ETU) mirror hanging from the lid of the 2 meter coating tank at NASA Goddard Space Flight Center (GSFC). This mirror was about to be coated with materials that make it's surface reflective to far-ultraviolet light. (Mar. 27, 1997).