Chapter 1: COS Overview 1.1 Instrument Capabilities and Design FUV Spectroscopy NUV Spectroscopy Grating Offset Positions (FPPOS) NUV Imaging Data Collection Modes 1.2 COS Physical Configuration 1.2.1 The COS Detectors 1.3 Basic Instrument Operations 1.3.1 Target Acquisitions 1.3.2 Routine Wavecals 1.3.3 Typical COS Observing Sequence 1.4 COS Coordinate System