DOI Descent Orbit Insertion DPS Descent Propulsion System DS Documented Sample DSE Data Storage Equipment DSKY Display and Keyboard DTO Detailed Test Objective DUA Digital Uplink Assembly DWN Down E Erasable or Enter EASEP Early Apollo Scientific Experiment Package ECS Environmental Control System ED Explosive Device EDT Eastern Daylight Time EFH Earth Far Horizon EI Earth (atmosphere) Interface EL Elevation or Electric EMS Entry Monitor System EMU Extravehicular Mobility Unit ENH Earth Near Horizon EPO Earth Parking Orbit EPS Electrical Power Subsystem EQUIP Equipment EST Eastern Standard Time EVA Extravehicular Activity EVAP Evaporator EVT Extravehicular Transfer EXT External f F Stop FC Fuel Cell FDAI Flight Director Attitude Indicator FLT Flight FM Frequency Modulated FOV Field of View fps or FPS Feet per second FT or ft Feet FTO Flight Test Objective FTP Full Throttle Position GBI Grand Bahama Islands GBM Grand Bahama (MSFN) GDC Gyro Display Coupler GDS Goldstone, California GET Ground Elapsed Time GETI Ground Elapsed Time of Ignition GLY Glycol GMT Greenwich Mean Time G&N Guidance and Navigation GNCS Guidance Navigation Control System GWM Guam GYM Guaymas, Mexico H2 Hydrogen HA Apogee Altitude HAW Hawaii HBR High Bit Rate (TLM) HD Highly Desirable HGA High Gain Antenna HI High Hp Perigee Altitude HSK Honeysuckle (Canberra, Australia) HTR Heater HTV USNS Huntsville ICDU Inertial Coupling Data Unit ID Identification IGA Inner Gimbal Angle IGN Ignition IMU Inertial Measurement Unit iv