This Apollo Glossary compiled by Garry
Kennedy.
Astronaut switch details provided by Thomas Schwagmeier.
Last revised 25 October 2016.
Reference to the About Space website may also be fruitful.
- A
- One of four Omni Directional Control Antennas, known as Omni Alpha
- ACA
- Attitude Control Assembly
- ACQ
- Acquisition
- AELD
- Ascent Engine Latching Device
- AGC (1)
- Apollo Guidance Computer
- AGC (2)
- Automatic Gain Control, which is part of the TV system flown on Apollos 15-17, see Ground Controlled Television Assembly Manual. An AGC output meter is located on the LCRU.
- AGS
- Abort Guidance System
- ALHT
- Apollo Lunar Hand Tools
- ALM
- Alarm
- ALSCC
- Apollo Lunar Surface Close-Up Camera, also known as the Gold Camera after its developer, astronomer Tommy Gold
- ALSD
- Apollo Lunar Surface Drill; flown on Apollo 15, 16, and 17
- ALSE
- Apollo Lunar Sounder Experiment
- ALSEP
- Apollo Lunar Surface Experiments Package; collection of experiments flown to the lunar surface by Apollo 12, 14, 15, 16, and 17; see ASE, CCG, CPLEE, HFE, LACE, LDD, LSG, LSM, LSP, PSE, SIDE, and SWS
- ALSRC
- Apollo Lunar Sample Return Container
- ALT
- Altimeter
- ALIGN
- Alignment or Altitude or Alternate
- AM
- Ammeter or Amplitude Modulation
- AMP
- Ampere or Amplifier
- AMP-HR
- Ampere Hour
- ANNUN-NUM
- Annunciator/Numerics
- ANT
- Antenna
- AOS
- Acquisition Of Signal or Acquisition Of Site
- AOT
- Alignment Optical Telescope, which is basically just a sighting scope, with no magnification and a 60-degree field-of-view. The AOT is ceiling-mounted above the forward instrument panels and can be seen in Apollo 12 training photo
KSC-69PC-0594. There are six fixed viewing directions (the "detents"). The astronauts looked through the AOT and, using two sets of marks called the spiral and cursor, measured star locations so that the computer can determine LM orientation. A discussion of the
AOT has been assembled by Journal Contributor Adam Bootle.
- AP
- Alpha Particle (spectrometer)
- APS
- Auxiliary Propulsion System (S-IVB) or Ascent Propulsion System (LM)
- AR
- Relay Mode, Communications Mode of the Space Suit Communicator
- ARIA
- Apollo Range Instrumentation Aircraft
- ARM
- Armed
- ARS
- Atmosphere Revitalization System
- ASA
- Abort Sensor Assembly
- ASAP
- As Soon As Possible
- ASC
- Ascent
- ASE
- Active Seismic Experiment; part of the ALSEP instrumentation flown on Apollo 14 and 16
- ASP
- Apollo Simple Penetrometer; flown on Apollo 14
- ASR
- Area Surveillance Radar
- ASSY
- Assembly
- Astronaut Switches
- These switches were located at bottom of the ALSEP Central Station at the back.
For Apollo 12 and 15, there were three switches
- ASTRO SW #1
- - initial position is CCW (orange crescent to right)
- - to be rotated 180° CW
- - it bypasseses the HOLD-OFF circuit and must be operated by the astronaut
- ASTRO SW #2 (backup)
- - initial position is CCW (orange crescent to right)
- - to be rotated 180° CW by the astronaut only if the ground is unable to command XMTR A "ON"
- - switches the XMTR B "ON", DATA PROCESSOR Y "ON", and resets the RCVR circuit breaker
- ASTRO SW #3 (backup)
- - initial position is CCW (orange flag to upper right)
- - to be rotated 270° CCW (orange flag to upper left) by the astronaut only if the ground is unable to command the Experiments "ON"
- - it sequentially activates the experiments in 1, 2, 4, 3 order to OPER SELECT
For Apollo 14 and 16 there were five switches.
- ASTRO SW #1, #2, and #3 are the same as for A12/A15; the two additional switches are for the ASE.
- ASTRO SW #4 (backup)
- - initial position is CCW (orange crescent to right)
- - to be rotated 180°ree; CW by the astronaut only if the ground is unable to command the ASE "ON" and/or high bit rate (HBR) "ON"
- - activates ASE OPER SELECT and switches DATA PROCESSOR to ASE HBR ON
- ASTRO SW #5
- - initial position is CW (unpainted crescent to left)
- - to be rotated 180° CCW (cover all four trinagular shapes)
- - it must be CCW to operate the ASE, activates ASE STBY SELECT, switches DATA PROCESSOR to ASE HBR OFF (return to normal bit rate (NBR)), switched to interrupt ASE 29V OPER PWR line; safety feature
For Apollo 17, there were two switches.
- ASTRO SW #1 (backup)
- - Spring-loaded to the CCW position
- - if ALSEP fails to start up normally, upon request the astronaut rotates SW #1 CW and back CCW
- - applies power to redundant Power Conditioning Unit (PCU 2)
- ASTRO SW #2
- - LSPE safety switch
- - CW rotation enables LSPE +29V-DC operational power line, CCW rotation inhibits the LSPE
- ATCA
- Attitude & Translation Control Assembly
- ATT
- Attitude
- AUTO
- Automatic
- AUX
- Auxiliary
- AVAIL
- Available
- Average G
- A computer program for dealing with gravitational acceleration that permits an accurate trajectory calculation.
- AZ
- Azimuth
- B
- One of Four Omni Directional Control Antennas, known as Omni Bravo
- BAT or BATT
- Battery
- BB
- A BB is a shot pellet 0.175 inch ( 0.44 cm) in diameter, usually used in an air rifle.
- BCN
- Beacon
- BEF
- Blunt End Forward
- BIP
- Bipropellant
- BMAG
- Body-Mounted Attitude Gyro
- BP
- Barber Pole
- BPS
- Bits Per Second or Bits Per Sample
- BRA
- Bag Restraint Assembly. "BRA" is probably an after-the-fact, made-up acronym. It was a mesh bag with two compartments that was used to keep the helmets out of the way during in-cabin operations. The name undoubtedly comes from its resemblance to a brassiere.
- BSLSS
- Buddy Secondary Life-Support System, a set of hoses and connectors which allowed the astronauts to share cooling water in the event that one of the PLSSs failed
- BTH
- Both
- BTU
- British Thermal Unit
- BUSS
- Biomedical Urine Sampling System
- C
- One of Four Omni Directional Control Antennas, known as Omni Charlie
- CAB
- Cabin
- CAL
- Calibrate or Calibration
- CALC
- Calculate or Calculated
- CAPCOM
- Spacecraft Communicator
- CB
- Circuit Breaker
- C-BND
- C-Band
- CBL
- Cable
- CC
- Contact Closure
- CCFF or C Squared-F Squared
- Crew Compartment Fit and Function
- CCIG
- Cold Cathode Ion Gauge experiment; was part of the ALSEP instrumentation
flown on Apollo 12, 14, and 15
- CDR
- Commander
- CDH
- Constant Delta Height
- CDU
- Coupling Data Unit
- CES
- Control Electronics Section; controls LM attitude and translation about all three axis
- CG
- Center of Gravity
- CHAR
- Character
- CIR
- Circuit or Circuit Breaker
- CIRC
- Circularization
- CL
- Close
- CLSD
- Closed
- CM
- Command Module
- CMC
- Command Module Computer
- CMD
- Command
- CMDED
- Commanded
- CMP
- Command Module Pilot
- CNTL
- Control
- CO2
- Carbon Dioxide
- COAS
- Crewman Optical Alignment Sight. Discussion.
- COMM
- Communications
- COMP
- Compare or Component
- COND
- Condition, Conditioning or Conditioner
- Config
- Configuration
- CONT
- Continue
- COOL
- Coolant
- CP
- Command Pilot or Control Point
- CPLEE
- Charged Particle Lunar Environment Experiment; part of the ALSEP instrumentation flown on Apollo 14
- CPS
- Cycles Per Second
- CRD
- Cosmic Ray Detector; flown on Apollo 16 and 17
- Cross-pointer or X-Pointer
- Article. See, also, the Apollo 15 discussion following
104:41:54.
- CRSFD
- Crossfeed
- CRT
- Cathode-Ray-Tube
- CRYO
- Cryogenic
- CSC
- Close-up Stereo Camera or Contingency Sample Collection
- CSI
- Coelliptic Sequence Initiation
- CSM
- Command and Service Module
- CSQ
- Call sign of NASA tracking ship Coastal Sentry Quebec which according to the authors of On the Shoulders of Titans: A History of Project Gemini ( Appendix F ) was "originally a C1-M-AVI class freighter, considerably modified as tracking ship."
- CSRC
- Contingency Sample Return Container
- CTG
- Cartridge
- CTV
- Color Television
- CUR
- Current
- CWEA
- Caution and Warning Electronics Assembly
- CWG
- Constant Wear Garment, the Long-Johns
- D
- Downward Thrusting RCS Engine or One of Four Omni Directional Control Antennas, known as Omni Delta
- DAC
- Digital to Analog Converter or Data Acquisition Camera
- DAP
- Digital Autopilot
- DB
- Decibel
- DC
- Direct Current
- DCA
- Digital Command Assembly
- DECA
- Descent Engine Control Assembly
- DECR
- Decrease
- DEDA
- Data Entry and Display Assembly
- DEG
- Degree
- Delta H
- Height Difference
- Delta P
- Pressure Difference
- Delta T
- Time Difference
- Delta V
- Change in Velocity
- DESC
- Descent
- DET
- Detent or Detector or Digital Event Timer
- DF
- Direction Finding
- DFI
- Development Flight Instrumentation
- DIFF
- Difference or Differential
- DIG
- Digital
- DIR
- Direct
- DISCH
- Discharge
- DISP
- Display
- DIV
- Diverter
- Dixie Cup
- This nickname refers to the cup-shaped, individual sample bags that were used on Apollo 12, 14, and 17. The nickname derives from a brand of wax-coated, paper drinking cups which, like such brands as Kleenex and Xerox, became a generic name because of widespread popularity. The following is a brief history. The first disposable, individual drinking cups were developed by Lawrence Luellen in 1907-8 and, in the next decade, gained market acceptance due to increasing concerns about disease spread by use of common-use dippers and glasses. The company was later headed by Hugh Moore and, in 1919, the cup, which had been known as the Health Cup, acquired the Dixie Cup brand-name and national prominence as a result of the Influenza Epidemic that struck after World War I.
- DLAY
- Delay
- DOI
- Descent Orbit Insertion
- DPLY
- Deploy or Deployed
- DPS
- Descent Propulsion System
- DR
- Dead Reckoning or Descent Rate
- DRT
- Dome Removal Tool. Used to remove the dome from a plutonium fuel cask mounted on the side of the LM next to the Scientific Equipment Bay (SEB). Removal of the dome gives access to the plutonium fuel element used to power the RTG (Radio-isotope Thermo-electric Generator). The fuel element is removed from the cask with the Fuel Transfer Tool (FTT). On the lefthand side of the illustrationAl Bean is shown with the Apollo 12 DRT attached to the cask dome.
- DSE
- Data Storage Equipment
- DSEA
- Data Storage Electronics Assembly
- DSKY
- Display and Keyboard Assembly (LM photo and diagram)
- DSN
- Deep Space Network
- EASEP
- Early Apollo Surface Experiment Package; collection of experiments flown on Apollo 11; see ASE and LRRR
- ECA
- Electrical Control Assembly
- ECOM
- Electronics Communications
- ECS
- Environmental Control System
- ED
- Explosive Device
- EDS
- Emergency Detection System
- E-DUMP
- Erasable-Memory Download from Spacecraft; also known as E-MOD
- ELS
- Earth Landing System
- EMI
- Electromagnetic Interference
- E-MOD
- Erasable-Memory Download from Spacecraft; also known as E-DUMP
- EMU
- Extravehicular Mobility Unit; Space Suit and Backpack combination
- EPS
- Electrical Power System
- ETB
- Equipment Transfer Bag. Apollo 11 training photo S69-31080 showing the ETB attached to the near side of the MESA.
- EV
- Extravehicular
- EVA
- Extravehicular Activity
- EVCS
- Extravehicular Communications Systems
- F
- Fahrenheit or Forward Thrusting RCS Engine
- FAIL
- Failure
- FAM
- Familiarization
- FDAI
- Flight Director Attitude Indicator
- FDO or FIDO
- Flight Dynamics Officer
- Fiducial
- The various Hasselblad cameras had a plate next to the film that superimposed references marks (reseau crosses) on the film. In the text, the location of an object in an image is sometimes indicated by reference to the reseau crosses=fiducials. Details linked here.
- Filling a Square
- Charlie Duke provided the following explanation at 148:06:03
Duke - "Well, in the military, you have a set of requirements you've got to do to, like, stay current in an airplane. You need so many landings, you need so many approaches, you need so many whatevers. So they have a matrix, you know; and across the top you have columns and the horizontal axis it might be the dates or something like that. And when you get one, you filled the square; you'd make a check mark and that was called 'filling the square'."
- FITH
- Fire In The Hole
- FL
- Flag
- FM
- Frequency Modulation
- FP
- Flight Progress
- FRAG
- Fragment
- Fremantle
- Port city in Western Australia at the mouth of the Swan River estuary; about 15 kilometers from the Western Australia capital, Perth, which is also on the Swan.
- FREQ
- Frequency
- FTT
- Fuel Transfer Tool. Used to extract the plutonium fuel from the cask mounted on the side of the LM next to the Scientific Equipment Bay (SEB) and then to load the fuel element into the RTG (Radio-isotope Thermo-electric Generator). On the lefthand side of the illustrationFred Haise is shown attaching a training version of the DRT attached to the a mock-up fuel element.
- FUS
- Far-Ultraviolet Spectrometer
- FWD
- Forward
- GASC
- Gas Analysis Sample Container
- GASTA
- Gimbal Angle Sequencing Transformation Assembly
- G&C
- Guidance and Control
- GCA
- Ground Controlled Approach
- GCTA
- Ground-Command Television Assembly
- GDA
- Gimbal Drive Actuator
- GDC
- Gyro Display Coupler
- GDO
- Guidance Dynamics Officer
- GET
- Ground-Elapsed Time
- GETI
- Ground-Elapsed Time of Ignition
- GLY
- Glycol
- GMBL
- Gimbal
- G&N
- Guidance and Navigation
- GNCS
- Guidance, Navigation and Control System
- GND
- Ground
- Gnomon
- Tool consists of a weighted staff suspended on a two-ring gimbal and supported by a tripod. The staff extends 12 inches above the gimbal and is painted with a gray scale. The gnomon is used as a photographic reference to indicate local vertical, sun angle, and scale
- GOX
- Gaseous Oxygen
- GROVER
- Geological Rover; an alternate name for the 1-g training version of the Lunar Roving Vehicle (LRV)
- GUID
- Guidance
- H
- Height (altitude)
- Handover
- "'Handover' basically means handover from one ground station to another of 'uplink' voice, command and ranging.
'Downlink' signals can be taken from any station in view and configured, regardless of uplink. And, of course, telemetry, voice, and TV could all be selected from different sites. Also bear in mind that there could be three uplinks - CSM, LM and EASEP/ALSEP. The 9m stations (CRO, HAW, GWM on this longitude) were generally used for the EASEP/ALSEP support." (Mike Dinn, Deputy Director of the Honeysuckle Tracking Station during Apollo)
- HBLAD
- Hasselblad Camera
- HBR
- High Bit Rate
- HCEX
- Highspeed Color Ektachrome Film
- H-Dot
- Time derivative of height (H); Descent Rate or Ascent Rate. In mathematical notation, the time (t) derivative of height (H) can be written as dH/dt or as Ḣ
- HE
- Helium
- HEDC
- Hasselblad Electric (Electronic?) Data Camera
- HFE
- Heat Flow Experiment or Heat Flow Electronics; part of the ALSEP instrumentation flown on Apollo 15, 16, and 17
- HGA
- High Gain Antenna
- H/H
- Altitude or Altitude Rate
- HI
- High
- HL
- High Level
- HLD
- Hold
- H2O
- Water
- HSD
- High-Speed Data
- HTC
- Hand-Tool Carrier
- HV
- High Voltage
- HVR
- Hover
- H/X
- Heat Exchanger
- IAU
- International Astronomical Union
- ICS
- Intercommunications System
- ID
- Identification
- IFR
- Instrument Flight Rules
- IG
- Inner Gimbal
- IGA
- Inner Gimbal Angle
- IGN
- Ignition
- ILS
- Instrument Landing System
- IMU
- Inertial Measurement Unit
- IN
- Inlet
- INCO
- Instrumentation and Communications Officer
- INCR
- Increase
- INJ
- Injector
- INST
- Instrumentation
- INTEG
- Integrity
- INVTR
- Inverter
- IP
- Initial Point
- IPI
- Integrated Position Indicator
- IRIG
- Inertial Rate Integrating Gyro
- ISA
- Interim Stowage Assembly. As indicated in the diagram, the ISA is a set of stowage bags on a framework that fits over the Commander's PLSS when the latter is mounted on the wall behind the CDR's left shoulder. An ISA can be seen on the left at Neil Armstrong's back in Apollo 11 training photo
KSC-69PC-319. When the PLSS is in use, the ISA is put somewhere out of the way and, for the return to lunar orbit, it is attached to the aft bulkhead. Journal Contributor David Woods notes that after rendezvous with the Command Module, the ISA is transferred over, probably without the framework, for return to Earth.
- ISOL
- Isolation
- ISR
- Infrared Scanning Radiometer
- ISS
- Inertial Sensor System or Interim Stowage Shelf
- IU
- Instrument Unit
- IV
- Intravehicular
- IVA
- Intravehicular Activity
- JETT
- Jettison
- JD
- Jet Driver
- JPL
- Jet Propulsion Laboratory
- K-bird
- KC-135 aircraft
- K factor
- Ground elapsed time is defined as the time difference between
current Greenwich Mean Time and Greenwich Mean Time of Apollo
liftoff from the Earth. Because of the AGS computer word size,
Ground Elapsed Time cannot be used for AGS time. Instead, a time
bias (K-factor) is subtracted from Ground Elapsed Time and the resulting
time used as AGS time. The bias used equals the Ground Elapsed Time
when the AGS computer time is initialized at AGS time zero. (Section 9.1 in LM/AGS Operating Manual, Flight Program 6, 36Mb)
- KEY REL
- Key Release. Frank O'Brien writes, "There is both a key, and a light on the DSKY for the Key Release function. As the AGC is a multiprogrammed computer, just like your PC/Mac/Linux/whatever, there are times when one program wants to get your attention while you are working with another program (ex: you are listening to music, and your appointment calendar program needs to alert you to a meeting starting in five minutes). The program, recognizing that another program has control of the DSKY, will flash the "KEY REL" light, asking the astronaut to allow the program access to the display. Pressing the "KEY REL" key transfers control to the program requesting attention.
- KSC
- Kennedy Space Center
- L&A
- Landing and Ascent facility; which consisted of a site model mounted upside down over a moveable TV camera. The TV picture was then fed to displays in the windows of the LM simulator.
- LACE
- Lunar Atmospheric Composition Experiment; part of the ALSEP instrumentation flown on Apollo 17
- LAD
- Lunar Atmosphere Detector
- LAM
- Landing Area Map (???)
- LAT
- Latitude or Lateral
- LBR
- Low Bit Rate
- LCG
- Liquid-Cooled Garment
- LCRU
- Lunar Communications Relay Unit
- LDD
- Lunar Dust Detector; part of the ALSEP instrumentation flown on Apollo 12, 14, and 15
- LDG
- Landing
- LEAM
- Lunar Ejecta And Meteorite (experiment); part of the ALSEP instrumentation flown on Apollo 17
- LEB
- Lower Equipment Bay
- LEC
- Lunar Equipment Conveyor -
drawing courtesy of Karl Dodenhoff. The LEC attachment point in the cabin overhead is the yellow bar in Apollo 15 photo S71-40773, courtesy Gary Kitmacher, John Duncan, and Gary Neff.
- LEVA
- Lunar Extravehicular Visor Assembly; a polycarbonate shell and two visors with thermal control and optical coatings on them. Details and diagrams are linked here.
- LGC
- Lunar Module Guidance Computer
- LHSSC
- Left-Hand Side Stowage Compartment
- LIM
- Limit or Limits
- LiOH
- Lithium Hydroxide
- LLTV
- Lunar Landing Training Vehicle. See the discussion at 113:43:49 in the Apollo 17 Journal. John Osborn has provided an extensive set of photographs of the one LLTV that survived to the end of the Apollo program.
- LM
- Lunar Module
- LMP
- LM Mission Programmer or Lunar Module Pilot
- LMS
- Lunar Mass Spectrometer or Lunar Module Simulator
- LNP
- Lunar Neutron Probe (experiment); flown on Apollo 17
- LO
- Low
- LOI
- Lunar Orbit Insertion
- LONG
- Longitude
- LOPC
- Lunar Orbit Plane Change
- LOS
- Loss Of Signal or Loss Of Site
- LPD
- Landing Point Designator. The Commander can look through a set of scribe marks on his window and the LPD angle, which LMP gives him from the PGNS, will tell him where to look along the vertical scale to find the place where the computer thinks they are going to land. If the CDR doesn't like the spot, he can move his handcontroller to tell the computer that he wants to change the landing spot up or back or to either side. A single movement of the handcontroller, which moves the landing point by a half degree or so, is usually referred to by the astronauts as a "click". Journal Contributor Randy Attwood has provided views of the scribe marks from the
interior of LM-9 and from the
exterior. Note that there are scribe marks on both the innermost window surface and on the outermost. The CDR positions himself so that the two sets of marks are lined up.]
- LPI
- Lunar and Planetary Institute
- LPM
- Lunar Portable Magnetometer; flown on Apollo 14 and 16
- LR
- Landing Radar
- LRL
- Lunar Receiving Laboratory
- LRRR, LR Cubed, or LR3
- Lunar Ranging Retro-Reflector; flown on Apollo 11, 14, and 15. Further information can be found at the McDonald Observatory Website http://almagest.as.utexas.edu/~rlr/mlrs.html
- LRV
- Lunar Roving Vehicle; flown on Apollo 15, 16, and 17
- LSB
- Least Significant Bit
- LSCRE
- Lunar Surface Cosmic Ray Experiment
- LSG
- Lunar Surface Gravimeter; part of the ALSEP instrumentation flown on Apollo 17
- LSM
- Lunar Surface Magnetometer; part of the ALSEP instrumentation flown on Apollo 12, 15, and 16
- LSPE
- Lunar Seismic Profiling Experiment; part of the ALSEP instrumentation flown on Apollo 17
- LSUC
- Lunar Surface Ultraviolet Camera; flown on Apollo 16
- LTC
- Lunar Topographic Camera
- LTG
- Lunar Traverse Gravimeter (experiment); flown on Apollo 17
- LV
- Low Voltage
- LVL
- Level
- MA
- Master Alarm
- Mafic Minerals
- Mafic minerals are rich in magnesium and iron and are usually dark colored.
- MAG
- Magazine
- MAL
- Malfunction
- MAN
- Manual or Manifold
- MAP
- Message Acceptance Pulse
- MAX
- Maximum
- MCC
- Mission Control Center or MidCourse Correction
- MCCH
- Mission Control Center Houston
- MDC
- Main Display Console (CM)
- MESA
- Modular Equipment Stowage Assembly
- MET
- Mission Elapsed Time, Mission Event Timer, or Mobile Equipment Transporter. The Apollo 14 transporter was a two-wheeled rickshaw vehicle used to carry tools, containers, spare film, etc.
- MFC
- Main Feeder Contactor
- MG
- Middle Gimbal
- MGA
- Middle Gimbal Angle
- MIN
- Minimum
- Minus Y axis
- South side of the LM
- Minus Z axis
- East side of the LM
- MOCR
- Mission Operations Control Room
- M/P
- Mortar Pack
- MPA
- Mortar Pack Assembly
- MPX
- Multiplex
- MSB
- Most Significant Bit
- MSC
- Manned Spacecraft Center; now Johnson Space Center
- MSFN
- Manned Space Flight Network (pronounced "Miss Finn"); provides reliable, (usually) continuous, and instantaneous radio communications with the astronauts, launch vehicle, and spacecraft from lift-off to splashdown
- MSOB
- Manned Spacecraft Operations Building at the Kennedy Space Center. The training area that the astronauts used to practice the mechanics of ALSEP deployments and other EVA activities was located behind the MSOB. Other training activities, such as those involving a LM mock-up, were conducted in the building.
- MSSC
- Magnetic Shield Sample Container
- MTR
- Meter
- MTVC
- Manual Thrust Vector Control
- N204
- Nitrogen Tetroxide, oxidizer used in the DPS and APS
- N/A
- Not Applicable
- NASA
- National Aeronautics and Space Administration
- NAV
- Navigation
- NB
- Narrow Band
- NORM
- Normal
- NTS
- Nevada Test Site
- O2
- Oxygen
- OB
- OnBoard
- OCS
- Organic Control Sample
- OG
- Outer Gimbal
- OGA
- Outer Gimbal Angel
- OPN
- Open
- OPR
- Operate
- OPS
- Oxygen Purge System
- ORDEAL
- Orbital Rate Display Earth And Lunar; displays the computed local vertical in the pitch axis during Earth or Lunar orbit
- OTC
- Australia's Overseas Telecommunications Commision, which handled all telecommunications traffic with the res of the world. One of its functions, centered at its Paddington facility in Sydney, was to receive signals from the various tracking stations around the country and send them onward to NASA..
- OUT
- Outlet or Output
- OVR
- Over
- OVRD
- Override
- OX
- Oxidizer or Oxygen
- P00
- Program Zero-Zero, pronounced "pooh"; see a description of P00 provided by Frank O'Brien.
- P22
- P22 is the LM computer program that uses the rendezvous radar to track the Command Module.
- Parker Valves
- These propellant isolation valves were made by a U.S. unit of Parker Hannifin PLC and were part of the RCS propellant feed system and the valve switches were cycled open and closed by the LMPs immediately after landing, just in case something had gotten jarred. The control switches were located on the main LMP switch panel. Each of the four clusters of RCS jets was connected to two RCS systems and, consequently, there were eight switches, two for each RCS quad. Each switch had an Open and Close position.
- PA
- Power Amplifier
- PAD
- Preliminary Advisory Data: the crew had pre-printed forms on which they could write lift-off times and other data they would need in the event that communications was lost with Houston. Before and after each rest period, the CapCom would read up a list of lift-off times covering the next 10 to 12 hours and, prior to launch, a longer list of data was read up.
- PAO
- Public Affairs Office
- PART
- Partial
- PCA
- Program Coupler Assembly
- PCM
- Pulse Code Modulation
- PCT
- Per Cent
- PDI
- Powered Descent Initiation
- PFS
- Per Cent Full Scale
- PGA
- Pressure Garment Assembly
- PGNCS
- Primary Guidance, Navigation, and Control System
- PGNS
- Primary Guidance and Navigation System (pronounced "pings")
- PI
- Principal Investigator
- PIA
- Pre-Installation Acceptance
- PIPA
- Pulsed Integrating Pendulous Accelerometer
- PLSD
- Pulsed
- PLSS
- Portable Life Support System
- Plus Y axis
- North side of the LM
- Plus Z axis
- West side of the LM
- PM
- Phase Modulation
- PM1/NB
- Phase Modulator 1??/Narrowband
- PM1/WB, see the LCRU documentation
- Phase Modulator 1??/Wideband
- PNLS
- Panels
- PO
- Power Output
- POGO
- Partial Gravity Simulator; the name applied to this type of device derives from that of the Pogo Stick children's toy. An example of a POGO facility at NASA Johnson is linked here. Apollo 12 training photo S69-56059 shows Al Bean using a POGO device suspended from the gondola in a large centrifuge at NASA Johnson.
- POS
- Position
- PPK
- Personal Preference Kits
- PQMD
- Propellant Quantity Measuring Device
- PRA
- Program Reader Assembly
- PRD
- Personal Radiation Dosimeter
- PRELIM
- Preliminary
- PRESS
- Pressure
- PRIM
- Primary
- PRO
- Proceed
- PROG
- Program
- PROP
- Propellant or Propulsion
- PSE(P)
- Passive Seismic Experiment (Package); part of the ALSEP instrumentation flown on Apollo 11, 12, 14, 15, and 16
- PSIA
- Pounds Per Square Inch Absolute
- PSID
- Pounds Per Square Inch Differential
- PTA
- Pulsed Torque Assembly
- PTC
- Passive Thermal Control; also known as the Barbecue mode, in which the LM/CSM stack was oriented with its long axis perpendicular to the Sun so that, when the spacecraft were put into a slow rotation around that axis, heating and cooling would be relatively uniform.
- PTT
- Push-To-Talk
- PVR
- Percent Voltage Reference
- PWM
- Pulse Width Modulation
- PWR
- Power
- PYRO
- Pyrotechnic
- QD
- Quick Disconnect
- QTY
- Quantity
- QUAD
- Quadrant
- R
- (Computer) Register
- R-Dot
- Rate of approach; time (t) derivative of range, which can be written mathematically as dR/dt or Ṙ
- RAD
- Radiation
- Range Rate
- Change in range per unit time. In the case of a Rover traverse, if the driver is moving in a straight line away from the last Rover Nav initialization point, then the range rate is identical to the average speed. If, however, the driver has been making turns to avoid craters, then the range rate will be lower than the average speed.
- RC/OC
- Reverse Current/OverCurrent
- RCS
- Reaction Control System
- RCU
- Remote Control Unit
- RCVR
- Receiver
- REACQ
- Re-acquire
- REC
- Recorder
- RECD
- Received
- REF
- Reference
- REFSMMAT
- Reference Stable Member Matrix or, sometimes, Reference to Stable Member Matrix. See Charlie Duke's definition at 104:47:55
- REG
- Regulator
- REL
- Release
- Reseau Plate
- A glass plate fitted close to the film plane in the lunar surface Hasselblads. Details linked here.
- RET
- Retract or Return
- REV
- Reverse
- RF
- Radio Frequency
- RFLT
- Reflect or Reflected
- RGA
- Rate Gyro Assembly
- RLS
- Radius of Landing Site or Reference Landing Site
- RLY
- Relay
- RNG
- Range or Ranging
- ROD
- Rate of Descent
- RR
- Rendezvous Radar. The Rendezvous Radar was mounted on the top of the LM. The radar dish on LM-9, originally scheduled to be flown on Apollo 15 when that was an H mission, is shown in a
photo by Randy Attwood.
- RS
- Remote Site
- RSVR
- Resolver
- RTG
- Radioisotopic Thermoelectric Generator; used to provide power to the ALSEP experiments flown on Apollo 12, 14, 15, 16, and 17; also see SNAP-27
- RTV
- Room Temperature Vulcanizing silicone rubber insulation which was used, for example, on the handles of the Apollo geology hammers and on the tips of the fingers of the EVA gloves.
- RUPT
- Rupture
- S
- Sideward Thrusting RCS Engine
- SAS
- Space Adaptation Syndrome
- S-BND
- S-Band There were two S-band, high-gain antennas used by the LM crew. One was mounted on the top of the spacecraft, as can be seen in close-up in a LM-9
photo by Randy Attwood. The other was a large, umbrella-like antenna erected on the surface by the Apollo 12 and 14 crews. The Apollo 12 antenna can be seen on the righthand side of AS12-47-
6988
- SBT
- S-Band Transponder
- S/C
- Spacecraft
- SCB
- Sample Collection Bag
- SCE
- Signal-Conditioning Equipment
- SCS
- Stabilization and Control System
- SE
- Systems Engineer
- SEB
- Scientific Equipment Bay
- SEC
- Secondary, Second, or Special Environmental Container; the container when sealed will retain a high vacuum for study of lunar samples in its original environment
- SECS
- Sequential Events Control System
- SEF
- Sharp End Forward
- SEL
- Select
- SENS
- Sensitivity
- SEP
- Separation, Separator, or Surface Electric Properties (experiment). The SEP experiment was flown on Apollo 17
- SEQ
- Sequence or Scientific Equipment Bay
- SESC
- Special Environmental Sample Container
- SET
- Set or Setting
- SHE
- SuperCritical Helium
- SIDE
- Suprathermal Ion Detection Experiment; part of the ALSEP instrumentation flown on Apollo 12, 14, and 15
- SIG
- Signal
- SIM
- Scientific Instrument Module or Simulation
- SLA
- Spacecraft Launch Adapter or SM/LM Adapter
- SM
- Service Module
- SME
- Soil Mechanics Experiment
- SNAP-27
- System for Nuclear Auxiliary Power, Model 27
- S/O
- Shut Off
- SOL
- Solenoid
- SOV
- Shut Off Valve
- SP
- Spare
- SPEC
- Specification
- SPS
- Service Propulsion System
- SRC
- Sample Return Container; the rock boxes
- SRP
- Self-Recording Penetrometer; flown on Apollo 15 and 16
- S/S
- Samples per Second
- SSC
- SpaceSuit Communicator
- SSD
- Sun Shadow Device
- SSR
- Staff Support Room
- ST
- Static
- STGE
- Stage
- STBY
- Standby
- STR
- Strength
- STRB
- Strobe
- SUP
- Supply
- SUSP
- Suspension
- SVO
- Servo
- SW
- Switch
- SWC
- Solar Wind Composition Collector; flown on Apollo 11, 12, 14, 15, and 16
- SWIP
- Super Weight Improvement Program
- SWS
- Solar Wind Spectrometer; part of the ALSEP instrumentation flown on Apollo 12 and 15
- SYNCH
- Synchronization
- SYS
- System
- TB
- TalkBack
- TCA
- Thrust Chamber Assembly
- TCP
- Thrust Chamber Pressure
- TCU
- Television Control Unit
- TDS
- Thermal Degradation Sample; flown on Apollo 14
- TEC
- Transearth Coast
- TEI
- Transearth Injection
- TELEMU
- Telemetry
- TEMP
- Temperature
- Tephem
- Time of Ephemeris
- T/G
- Thumper/Geophone Experiment
- TGE
- Traverse Gravimeter Experiment; flown on Apollo 17
- THROT
- Throttle
- TIG or Tig
- Time of Ignition
- TJM
- Tower Jettison Motor
- TK
- Tank
- TLC
- Translunar Coast
- TLI
- Translunar Injection
- TLM or TM
- Telemetry
- TOL
- Tolerance
- TPI
- Terminal Phase Initiation
- TR
- Transmit/Receive
- TRANS
- Translation
- Travono (possibly Travano)
- A gray-brown plastic used in the LM to protect surfaces where metal could not be used. See Jim Irwin's discussion at 121:19:30. Also mentioned by John Young in a portion of the Apollo 16 Technical Debrief quoted after 106:48:11.
- TRUN
- Trunnion
- TSB
- Temporary Stowage Bag
- TTCA
- Thrust/Translation Controller Assembly
- TTHR
- Tether
- TTY
- Teletype or Teletypewriter
- TVC
- Thrust Vector Control
- U
- Upward Thrusting RCS Engine
- UCTA
- Urine Collection and Transfer Assembly
- UDMX
- Unsymmetrical-Dimethylhydrazine, part of the fuel for the DPS and APS
- UHF
- Ultra-High Frequency
- UHT
- Universal Handling Tool
- UVC
- Ultraviolet Camera; flown on Apollo 16
- V
- Volt
- V sub I
- Inertial Velocity
- VAC
- Volts Alternating Current
- VAR
- Variable
- VDC
- Volts Direct Current
- VEL
- Velocity
- VHF
- Very High Frequency
- VLV(S)
- Valve(s)
- VOX
- Voice Activated Transmission
- VPI
- Valve Position Indicator
- VR
- Vector Ranging
- VRMS
- Volt Root Mean Square
- W
- Watt
- WB
- WideBand
- W/B
- Water Boiler
- WILCO
- Will Comply
- X
- Cross
- X Axis
- Vertical Axis
- XMTR
- Transmitter
- X-Pointer
- See Crosspointer
- XPNDR
- Transponder
- Y Axis
- Left to Right Axis
- Z Axis
- Fore/Aft Axis
- Z Bag
- Storage Bag stored at the minus Z Bulkhead