AM- Airlock Module, also Amplitude Modulation.

APCS- Attitude and Pointing Control System.

ASMU- Automatically Stabilized Maneuvering Unit.

ATM- Apollo Telescope Mount.

ATMDC- Apollo Telescope Mount Digital Computer.

BMMD- Body Mass Measurement Device.

CM- Command Module.

CMC- Command Module Computer.

CMG- Control Moment Gyro.

COAS- Crewman Optical Alignment Sight.

CS- Crew Station.

CSM- Command and Service Module.

DA- Deployment Assembly.

DAC- Data Acquisition Camera.

db- Decibel.

DCS- Digital Command System.

DNA- Deoxyribonucleic Acid.

DSKY- Display Keyboard.

DT- Delayed Time.

ECS- Environmental Control System.

EEG- Electroencephalogram.

EPS- Electrical Power System.

EREP- Earth Resources Experiment Package.

ESS- Experiment Support System.

EVA- Extravehicular Activity.

FAS- Fixed Airlock Shroud.

FM- Frequency Modulation.

GMT- Greenwich Mean Time.

GSFC- Goddard Space Flight Center.

HCO- Harvard College Observatory.

HHMU- Hand Held Maneuvering Unit.

HSS- Habitability Support System.

IU- Instrument Unit.

IVA- Intravehicular Activity.

JSC- Johnson Space Center.

KSC- Kennedy Space Center.

LO- Liftoff.

LSU- Life Support Umbilical.

LV- Launch Vehicle.

MCC- Mission Control Center.

MDA- Multiple Docking Adapter.

MSFC- Marshall Space Flight Center.

NASA- National Aeronautics and Space Administration.

NRL- Naval Research Laboratory.

OMSF- Office of Manned Space Flight.

OWS- Orbital Workshop.

PCM- Pulse Code Modulation.

PI- Principal Investigator.

PS- Payload Shroud.

RNA- Ribonucleic Acid.

RPM- Revolutions Per Minute, also Roll Positioning Mechanism.

SAL- Scientific Airlock.

SAS- Solar Array System.

S/C- Spacecraft.

SL- Skylab. SM- Service Module.

STDN- Spacecraft Tracking and Data Network.

TACS- Thruster Attitude Control System.

TCS- Thermal Control System.

TM- Telemetry.

TV- Televison.

UV- Ultraviolet.

VHF- Very High Frequency.

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