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Focal Plate Assembly   Fibers selected for use are positioned
onto a thin, flat, steel plate during target configuration.
After all fibers are in place, a vacuum is applied on the back
side of the plate to warp it against a spherical backstop. This
both draws the fibers onto the true focal surface and aligns
them axially with the telescope exit pupil.  Unused fibers are
left positioned in either stow or park positions, located around
the outer circumference of the assembly. These positions are at
a depth lower than the surface of the warpable plate so that
fibers in use can cross over unused neighbors.  There are 288
total fiber positions evenly spaced around the focal plate
numbered from 0 through 287. The red fibers occupy every third
position beginning at location 1 and include an additional two
fibers at positions 276 and 279 (spares which can be used with
the nominal complement). The blue fibers are also located at a
spacing of every third posi