8. INSTALL THE SCUFF PLATES.

The scuff plates provided structural protection and some support during the HST's trip to orbit in the Space Shuttle's cargo bay. The Keel fitting and the Trunnions provided the main structural connections between the HST and the Shuttle.

• From sheet A release one yellow AFT TRUNNION SCUFF PLATE. Place its I-shaped slot over one yellow trunnion which protrudes from the PRIMARY MIRROR ASSEMBLY, 90 degrees on either side of the keel fitting. Fit it at right angles to the trunnion, with the curved side facing in the direction of the keel fitting. Secure with glue.

• Repeat with the other AFT TRUNNION SCUFF PLATE, on the opposite side.

• From sheet A release one yellow and silver FWD SCUFF PLATEs. Hold it with the yellow and silver side towards you. Bend its four silver legs down away from you, making a crease where the silver legs meet the edge of the yellow plate.

• Bend the four silver foot-pads up towards you, and adjust all the bends so the piece will sit like a table on a flat surface.

  

• Release the other FWD SCUFF PLATE from Sheet A, and prepare as above. Apply glue to the bottoms of the foot-pads on both pieces.

• These SCUFF PLATEs will be placed on opposite sides of the forward TELESCOPE TUBE, even with the word NASA. Each piece is different, and can only go on one side, as follows: The long foot-pads with holes will face aft, and the curved edges of the yellow plates will face in the direction of the word NASA. They go at 3 and 9 o'clock, if the aperture door were at 12. Secure with glue in the locations described above. The yellow plates should be in the same plane as the AFT TRUNNION SCUFF PLATEs. Adjust and reposition as necessary, before the glus dries, so they will be symmetrical.