Computer-aided design view of the VIS instrument. VIS consists of five units, three in the Payload Module and two in the Service Module. The Focal Plane Array dimensions are approximately 600 × 500 × 400 mm; the Shutter 475 mm × 375 mm × 250 mm; the Calibration Unit 170 mm × 160 mm × 130 mm; the Control and Data Processing Unit 285 mm × 285 mm × 230 mm; and the Power and Mechanism Control Unit 335 mm × 285 mm × 130 mm. The harness connecting these units together, and to the Service Module, are not shown, nor is the radiator to space. This is attached to the rear of the Focal Plane Array to radiate the power dissipated by the Readout Electronics in the Focal Plane Array. The harness and radiator can be seen in Fig. 4.