... Aperture and pixel sizes decreased to approximately 0.86 of their pre-COSTAR values. ... FOS post-COSTAR aperture locations updated; SMOV ends . ... The FOS aperture wheel, located at the HST focal surface, contained separate sets of single or paired apertures (including one blank for background measurements) for each detector which ranged in size from 0.1" to 4.3" (pre-COSTAR) projected onto the sky. ... FOS/BL: 0.0064 counts s-1 diode-1 . ... A pre-COSTAR diode was 0.356" wide and 1.43" high. ...