Editing List of Acronyms and Abbreviations

This list contains definitions for [[Orbiter]] or important [[spaceflight]] acronyms or abbreviations, especially those appearing in [[MFD|MFDs]] and various [[HUD]] modes.

One entry in this list consists of a term with one or more definitions, like:

;Term:Definition
<pre>
;Term:Definition
</pre>

Don't use links in the term part of a entry, please do so in the definition part, for keeping a consistent look-and-feel and don't putting to much emphasis on a single definition.

Terms without definitions will get moved to the talk page into the section "Wanted definitions". If you have multiple definitions for a term, the definition part should turn into a numbered list, like:
;Term:
#Definition 1
#Definition 2
#Definition 3

<pre>
;Term:
#Definition 1
#Definition 2
#Definition 3
</pre>

The order of the definitions should be like that:
#Orbiter HUD definitions
#Orbiter MFD definitions
#General Orbiter definitions
#Orbiter [[Add-on]] definitions
#General spaceflight definitions

If you don't agree to a ordering of definitions, please complain in the [[Talk:List_of_Acronyms_and_Abbreviations|talk]] page about the entry.

==See also==

* [[Russian glossary]]
* [[List of Acronyms and Abbreviations/ISS|List of Acronyms and Abbreviations for the ISS]]

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{{compactTOC}}

=A=
;AgP:[[Argument of periapsis]]:The angle in the orbit from the point of the ascending node to the point of periapsis, Used in OrbitMFD.
;Alt:[[altitude]], distance from the body surface
;AN:[[ascending node]]:a vector in an orbit where the body passes from south to north of the plane of reference (i.e. ecliptic or equatorial). Shown in [[Orbit MFD]] as a dotted vector line connecting to a solid square on the orbit.
;AORP:'''A'''utonomous '''O'''rbiter '''R'''apid '''P'''rototype, a system to allow a [[STS|shuttle]] orbiter to land without [[crew]].
;ApA:[[apoapsis]] apoapsis altitude, the lowest altitude of an orbit. Used in OrbitMFD mode.
;ApD:[[apoapsis]] apoapsis distance
;ApR:[[apoapsis]] apoapsis radius
;ApT:time to [[apoapsis]] in seconds
;AR:'''a'''cceptance '''r'''eview
;atmo:[[atmosphere]]
;ATV:
#'''A'''utonomous '''T'''ransfer '''V'''ehicle, an unmanned cargo spacecraft, see [[ATV]].
#'''A'''utomated '''T'''ransfer '''V'''ehicle[http://www.orbiterwiki.org/wiki/ATV#The_ATV]
;AU:[[astronomical unit]]

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=B=
;BMW:'''B'''ate, '''M'''ueller, '''W'''hite - authors of ''Fundamentals of Astrodynamics'' (1971)

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=C=
;CaLV:'''Ca'''rgo '''l'''aunch '''v'''ehicle, see [[Ares V]]
;CDI:[[course deviation indicator]]
;CDR:
#commander
#'''c'''ritical '''d'''esign '''r'''eview
;CEV:'''C'''rew '''e'''xpedition '''v'''ehicle, see [[CEV]]
;CFD:computational fluid dynamics
;CLV:'''C'''rew '''l'''aunch '''v'''ehicle, see [[Ares I]]
;COAS:'''C'''rew '''O'''ptical '''A'''lignment '''S'''ight
;COM:communication or communicator
;CTD:[[crash to desktop]]
;CTRL:Control
;CTV:
#'''C'''rew '''T'''ransfer '''V'''ehicle, a manned spacecraft derived from the [[ATV]], see [[CTV]]
#'''C'''ompatibility '''T'''est '''V'''an, '''NASA'''
;CVEL:
#[[closing velocity]]
#'''C'''ommon '''V'''essel '''E'''xtensions '''L'''ight, see [[CVEL]]

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=D=
;D3D9:refers to the advanced graphics client in [[Orbiter]].
;DDT&E:'''d'''esign, '''d'''evelopment, '''t'''est and '''e'''valuation
;DG:[[Delta-glider]]
;DG4:Orbiter's stock '''DG'''
;DGIII:[[DeltagliderIII]], a famous enhanced version of the [[Delta-glider]].
;DGIV:[[DeltaGliderIV]], an improved version of the [[DeltaGliderIII]].
;DG-S:[[Delta-glider]] equiped with two [[scramjet|scramjets]].
;Dir:'''dir'''ection
;Dist:'''dist'''ance
;DIV:[[divergent]], i.e. [[yaw]] [[gimbal]] mode.
;DLng:longitude difference, as seen on the [[synchronise orbit MFD]]
;DN:[[descending node]]
;DNP:dynamic [[pressure]]
;DNS:atmospheric density
;DPS:'''D'''ata '''P'''rocessing '''S'''ystem. Term describing the general purpose computers and their interfaces onboard various manned spacecraft.
;DST or Dst:distance (to target)
;DTe:time to [[ejection]], as seen on the [[transfer MFD]]
;DTi:time to intercept, as seen on the [[transfer MFD]]
;DTmin:time of arrical difference, as seen on the [[synchronise orbit MFD]]
;Dv:delta [[velocity]], as seen on the [[transfer MFD]], see also [[Delta-V]]

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=E=
;Ecc:[[eccentricity]]
;ECL:plane of the [[ecliptic]]
;ECLSS:'''E'''nvironmental '''c'''ontrol and '''l'''ife '''s'''upport '''s'''ystem
;ECSS:'''e'''uropean '''c'''ooperation for '''s'''pace '''s'''tandardization
;EELV:Evolved Expendable Launch Vehicle
;EQU:plane of the [[equator]]
;ESA:[[European Space Agency]]
;ESAS:[[w:Exploration Systems Architecture Study|Exploration Systems Architecture Study]]
;ET:[[external tank]]
;EVA:'''E'''xtra '''v'''ehicular '''a'''ctivity, see [[EVA]]

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=F=
;FGB:Russian abbreviation for Functional Cargo Block. See [[FGB]]
;FoV:field of view, as seen in the [[general information display]]
;FPS:[[frame rate]] (frames per second), as seen in the [[general information display]]
;FRF:'''F'''light '''R'''eadiness '''F'''iring, a launch countdown test of the Shuttle running all except SRB ignition and lift-off.

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=G=
;g:a unit of acceleration. 1g equals the gravity acceleration on earths surface, 9.81 m/s²
;GET:'''G'''round '''E'''lapsed '''T'''ime [http://history.nasa.gov/SP-4029/Apollo_00c_Introduction.htm]
;GL:Used often as vehicle name prefix for a [[Delta-glider]]
;GLOC:'''G'''ravity-induced '''L'''oss '''o'''f '''C'''onsciousness  
;GMT:Greenwich Mean Time.See [[w:Universal Time|Universal Time on Wikipedia]]
;GPDS:[[GPDS|Generic Payload Description System]]
;GPS:'''G'''lobal '''P'''ositioning '''S'''ystem
;GS:[[ground speed]]
;GTO:[[GTO|'''g'''eostationary '''t'''ransfer '''o'''rbit]]

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=H=
;H:Horizon
;HAC:[[Heading Alignment Cone]]
;HLLV:'''h'''eavy '''l'''ift '''l'''aunch '''v'''ehicle
;HSI:[[horizontal situation indicator]]
;HST:[[Hubble Space Telescope]]
;HTO:[[hypothetical transfer orbit]], as seen on the [[transfer MFD]]
;HUD:[[heads up display]]

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=I=
;IAS:indicated air speed [http://en.wikipedia.org/wiki/Indicated_air_speed]
;IDS:[[instrument docking system]]
;ILS:
#[[instrument landing system]]
#'''I'''nternational '''l'''aunch '''s'''ervices, a US-russian joint venture marketing [[Atlas]] and [[Proton]] launches
;Inc:Inclination (http://en.wikipedia.org/wiki/Inclination)
;ISP:[[specific impulse]]
;ISS:[[International Space Station]]

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=J=
;JD:[[Julian date]]
;JSC:  Lyndon B. '''J'''ohnson '''S'''pace '''C'''enter
;JWST:'''J'''ames '''W'''ebb '''S'''pace '''T'''elescope


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=K=
;KISS:"Keep it simple, stupid!" Famous engineering dogma.[http://en.wikipedia.org/wiki/KISS_principle] 
;KSC:[[Kennedy Space Center]]

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=L=
;LAN:longitude of [[ascending node]] or local-area network
;LCC:
#'''l'''aunch '''c'''ontrol '''c'''enter
#'''l'''ife '''c'''ycle '''c'''ost
;LDEF:[[Long Duration Exposure Facility]]
;LEO:[[Low earth orbit]]
;LH2:Liquid Hydrogen
;LOCV: Loss of crew and vehicle
;LOX:Liquid Oxygen
;LPe:longitude of [[periapsis]]

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=M=
;m:metre
;M:Mega (SI prefix for 10<sup>6</sup>). Occasionally mass or [[mach]] number
;MCC:
#'''m'''id '''c'''ourse '''c'''orrection
#'''m'''ission '''c'''ontrol '''center'''
;MCC-H:'''m'''ission '''c'''ontrol '''c'''enter '''H'''ouston
;MCC-M:'''m'''ission '''c'''ontrol '''c'''enter '''M'''oscow
;MDR:'''m'''ission '''d'''efinition '''r'''eview
;MECO:'''m'''ain '''e'''ngine '''c'''ut'''o'''ff
;MET:'''M'''ission '''E'''lapsed '''T'''ime. See [[w:Mission Elapsed Time|Mission Elapsed Time on Wikipedia]].
;MFD:'''M'''ulti'''f'''unctional '''D'''isplay, see [[MFD]]
;MJD:[[modified Julian date]]
;MLP:[[Mobile Launcher Platform]]
;MMOD:'''M'''icro'''m'''eteorites and '''o'''rbital '''d'''ebris
;MMU:'''m'''anned '''m'''aneuvering '''u'''nit, see [[MMU]]
;MnA:[[mean anomaly]]
;MnL:[[mean longitude]]
;m/s:meters per second, the SI base unit of [[velocity]]
;MSx:Mission Specialist x


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=N=
;NAV:
#navigation
#[[navigation aid]]

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=O=
;OAT:outside air temperature
;Ob:obliquity of ecliptic (tilt of axis of rotation against plane of ecliptic)
;OBS:[[omni bearing selector]]
;OBT:[[orbit]], as seen on the [[orbit MFD]]
;OMBUU: '''O'''rbiter '''M'''id'''b'''ody '''U'''mbilical '''U'''nit
;[[OMP]]:'''O'''rbiter '''M'''ultiplayer '''P'''roject, an ongoing program to create a multiplayer server in Orbiter.
;OMS:'''O'''rbital '''M'''aneuvering '''S'''ystem, the 'main engines' of the [[space shuttle]] orbiter
;OS:[[orbital speed]]

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=P=
;P:position (sometimes radius) vector, as seen on the [[align orbital plane MFD]]
;p0:atmospheric pressure at sea level
;PAM:'''P'''ayload '''A'''ssist '''M'''odule, a family of solid upper stages for the [[Space Shuttle]]
;PAPI:'''P'''recision '''A'''pproach '''P'''ath '''I'''ndicators, lit runway centerline.
;PB:[[Shuttle PB]]
;PDR:'''p'''reliminary '''d'''esign '''r'''eview
;PDRS:'''P'''ayload '''D'''eployment and '''R'''etrieval '''S'''ystem, the official name of the robot arm of the Space Shuttle
;PeA:[[periapsis]] altitude. Altitude of periapsis above the surface of the orbited body
;PeD:[[periapsis]] distance. See PeR. 
;PeR:[[periapsis]] radius. Distance of periapsis from the center of the orbited body
;PeT:time to [[periapsis]] in seconds. 
;PG:[[prograde]]
;PLT:Pilot
;PMI:'''P'''rincipal '''m'''oments of '''i'''nertia, see [[PMI]]
;Pos:position
;PRJ:[[projection]], as seen on the [[orbit MFD]]
;PRR:'''p'''reliminary '''r'''equirements '''r'''eview
;PSx:Payload Specialist x

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=Q=
;QR: '''q'''ualification '''r'''eview

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=R=
;R:
#mean radius
#specific gas constant
;r0:atmospheric density at sea level
;Rad:
#radial distance
#angular unit ''radians''
;RAnm:[[true anomaly]] of reference axis, as seen on the [[synchronise orbit MFD]]
;RCS:[[reaction control system]], spacebourne orientation rocket system.
;R&D:'''r'''esearch and '''d'''evelopment
;RDT&E:'''r'''esearch, '''d'''evelopment, '''t'''esting and '''e'''valuation
;REF: '''Reference''', used in Align MFD to select a reference body.
;RG:[[retrograde]]
;RInc:[[relative inclination]], as seen on the [[align orbital plane MFD]]
;RKA:Russian Space Agency
;RMS:'''R'''emote '''M'''anipulator '''S'''ystem
;RS:Russian-side, used as prefix for orientation when describing ISS components.
;RSLS:'''R'''edundant '''s'''et '''l'''aunch '''s'''equencer, the computer systems responsible for the ignition of the SSMEs in the [[Space Shuttle]] orbiter.
;RTFM:'''R'''ead '''t'''he '''f'''ine (or many other '''f'''-words) '''m'''anual, a typical forum answer for questions already answered extensivly in the manual.
;RTLS:'''R'''eturn '''t'''o '''l'''aunch '''s'''ite, a [[Space Shuttle]] abort mode.
;RVel:relative [[velocity]]

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=S=
;SAR:
#'''S'''earch '''a'''nd '''r'''escue.
#'''S'''yntetic '''a'''perture '''r'''adar, a [[radar]] mode used for creating navigation maps or detect slowly moving ground vehicles.
;S/C: [[spacecraft|'''s'''pace'''c'''raft]]
;SDK:Software Development Kit [http://en.wikipedia.org/wiki/SDK]
;SDHLV:'''S'''huttle '''D'''erived '''H'''eavy '''L'''aunch '''V'''ehicle, see [[Ares V]] 
;SDLV:'''S'''huttle '''D'''erived '''L'''aunch '''V'''ehicle, see [[Ares]]
;SECO:
#'''S'''econdary '''E'''ngine '''C'''ut'''o'''ff
#'''S'''ustainer '''E'''ngine '''C'''ut'''o'''ff
;Sim:
#simulation time (in seconds), as seen in the [[general information display]]
#a common abbreviation for "simulator"
;SHP:[[ship]], as seen on the [[orbit MFD]]
;Sh-ToR:ship [[time-on-reference]], as seen on the [[synchronise orbit MFD]]
;SI unit: The metric system of measurement, the modern name, see [[SI unit]]
;SLF:shuttle landing facility, see [[Cape Canaveral]]
;SMa:[[semi-major axis]] 
;SMi:[[semi-minor axis]]
;SRB:'''S'''olid '''R'''ocket '''B'''ooster [http://en.wikipedia.org/wiki/Solid_rocket_booster]
;SRTM:'''S'''huttle '''r'''adar '''t'''opography '''m'''ission, see [[SRTM]].
;SSME:Space Shuttle Main Engines [http://en.wikipedia.org/wiki/SSME_%28rocket_engine%29]
;SSTO:[[Single_Stage_To_Orbit | Single Stage to Orbit]]
;STOVL:Short take-off, vertical landing. As performed by the DG on full fuel employing hover thrusters during takeoff.
;STP:static [[pressure]] 
;STS:'''s'''pace '''t'''ransportation '''s'''ystem, AKA space shuttle, see [[space transportation system]]

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=T=

;T:orbit period, measured in seconds
;TAEM:Terminal Area Energy Management
;TAS:true air speed [http://en.wikipedia.org/wiki/True_air_speed]
;TEI:'''T'''rans '''E'''arth '''I'''njection[http://en.wikipedia.org/wiki/Trans_Earth_Injection] 
;Tgt:target, esp. in [[docking]] mode
;Tg-ToR:target [[time-on-reference]], as seen on the [[synchronise orbit MFD]]
;TKS:russian spacecraft for the Almaz program, see [[TKS]]
;TLA:Three letter acronym for a '''t'''hree '''l'''etter '''a'''cronym.
;TLE:two-line elements 
;TLe:eject longitude, as seen on the [[transfer MFD]]
;TLi:intercept longitude, as seen on the [[transfer MFD]]
;TLI:Trans Lunar Injection
;Tn:time to node, as seen on the [[align orbital plane MFD]]
;TOFS:tangential offset [[docking MFD]]
;TrA:[[true anomaly]]
;TRK:Track ship, as displayed by [[map MFD]]
;TrL:[[true longitude]]
;TRL:'''t'''echnology '''r'''eadiness '''l'''evel
;Ts:length of siderial day
;Tth:predicted thrust time, as seen on the [[align orbital plane MFD]]
;TVEL:tangential [[velocity]]

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=U=
;UMMU:'''U'''niversal '''m'''anned '''m'''aneuvering '''u'''nit, popular add-on, see [[Universal MMU]].
;UNKS:unknown problems, you are aware of.
;UNK-UNKS:unknown problems, you are not aware of.
;UT:'''u'''niversal '''t'''ime, GMT. Not to be confused with [[UTC]] (Universial Time Co-ordinated). The latter is based on atomic clocks not astronomy, hence the occasional ''leap-second'' to correct UTC to GMT.

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=V=
;VASI:'''V'''isual '''A'''pproach '''S'''lope '''I'''ndicator, the glideslope lighting system ajacent to runways to guide pilots onto the correct angle of glideslope (normally 3 degrees).
;VC:
#virtual cockpit
#Visual C++, an IDE and C++ compiler by Microsoft. 
;Vel:[[velocity]]
;VOR:[[very high frequency omnidirectional radio]]
;VS:vertical speed
;VSA: [[Virtual Space Agency]]
;VTOL:'''V'''ertical '''T'''ake '''O'''ff and '''L'''anding

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=W=
;WBS:'''w'''ork '''b'''reakdown '''s'''tructure
;WPD:'''w'''ork '''p'''ackage '''d'''escription
;Wrp:time acceleration factor, seen in the [[general information display]]
=X=
;XPDR:[[transponder]]
=Y=
;YSC:Yokohama Science Center
=Z=
;ZM:zoom, as seen on the [[map MFD]]

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{{compactTOC}}

[[Category: Articles]]
[[Category:Glossary]]
@@ Line 41: / Line 41: @@
 =A=
-;ACC: Acceleration, used in [[Surface MFD]] to indicate increasing or decereasing horizontal speed of the ship in m/s<sup>2</sup>
+;AgP:[[Argument of periapsis]]:The angle in the orbit from the point of the ascending node to the point of periapsis, Used in OrbitMFD.
-;ACT: Activate, command button in [[RCS attitude MFD]] in docking mode to activate the programmed orientation to the target dock
+;Alt:[[altitude]], distance from the body surface
-;AgP:[[Argument of periapsis]]:The angle in the orbit from the point of the ascending node to the point of periapsis, displayed in [[Orbit MFD]]
+;AN:[[ascending node]]:a vector in an orbit where the body passes from south to north of the plane of reference (i.e. ecliptic or equatorial). Shown in [[Orbit MFD]] as a dotted vector line connecting to a solid square on the orbit.
-;ALT or Alt:[[altitude]], distance from the body surface
-#Used in [[Orbit MFD]] when Alt mode is selected to indicate distance from the surface of the body
-#Used in [[Surface MFD]] to indicate altitude in km from the body surface
-;AN:[[ascending node]]:a vector in an orbit where the body passes from south to north of the plane of reference (i.e. ecliptic or equatorial). Shown in [[Align MFD]] and [[Orbit MFD]] as a dotted vector line connecting to a solid square on the orbit.
-;AOA: Angle of attack, the difference between the ship's direction of travel and the pitch of its nose
-#Used in [[Surface MFD]] to indicate the angle of attack
 ;AORP:'''A'''utonomous '''O'''rbiter '''R'''apid '''P'''rototype, a system to allow a [[STS|shuttle]] orbiter to land without [[crew]].
-;AP: Used in [[Surface MFD]], a red rectangle with white "AP" in the altitude tape to indicate the altitude of the ship's apoapsis
+;ApA:[[apoapsis]] apoapsis altitude, the lowest altitude of an orbit. Used in OrbitMFD mode.
-;ApA:[[apoapsis]] apoapsis altitude, the lowest altitude of an orbit, displayed in [[Orbit MFD]].
 ;ApD:[[apoapsis]] apoapsis distance
-;ApR:[[apoapsis]] apoapsis radius, displayed in [[Orbit MFD]]
+;ApR:[[apoapsis]] apoapsis radius
-;ApT:time to [[apoapsis]] in seconds, displayed in [[Orbit MFD]]
+;ApT:time to [[apoapsis]] in seconds
-;AR:
+;AR:'''a'''cceptance '''r'''eview
-#'''A'''utomatic '''R'''eference, used in [[Align MFD]], [[Orbit MFD]] as a command button for Align to select a reference body automatically based on highest gravity
-#'''A'''ltitude '''R'''ange, used to manually set the range in the altitude graph in [[Ascent profile MFD]]
-#'''a'''cceptance '''r'''eview
 ;atmo:[[atmosphere]]
-;ATM DATA: Atmospheric data in [[Surface MFD]] readouts
 ;ATV:
 #'''A'''utonomous '''T'''ransfer '''V'''ehicle, an unmanned cargo spacecraft, see [[ATV]].
 #'''A'''utomated '''T'''ransfer '''V'''ehicle[http://www.orbiterwiki.org/wiki/ATV#The_ATV]
 ;AU:[[astronomical unit]]
-;AX: '''Ax'''is, command button in [[RCS attitude MFD]] to change the selected axis beetween pitch/yaw/roll
 [[#top|Back to top]]
 =B=
-;BAS: Basemode, command button to select programmed attitude (prograde, orbit normal, perpendicular in, radial down) in [[RCS attitude MFD]]
 ;BMW:'''B'''ate, '''M'''ueller, '''W'''hite - authors of ''Fundamentals of Astrodynamics'' (1971)
-;BRG: '''B'''ea'''r'''in'''g''', used in the [[Horizontal Situation Indicator MFD]] to indicate the compass direction of the ILS or VOR transmitter
 [[#top|Back to top]]
@@ Line 84: / Line 70: @@
 ;CEV:'''C'''rew '''e'''xpedition '''v'''ehicle, see [[CEV]]
 ;CFD:computational fluid dynamics
-;CFG: command button in [[RCS attitude MFD]] to switch to configuration page
 ;CLV:'''C'''rew '''l'''aunch '''v'''ehicle, see [[Ares I]]
-;CNC: Cancel, used in [[RCS attitude MFD]] in the docking mode to cancel the docking mode program
 ;COAS:'''C'''rew '''O'''ptical '''A'''lignment '''S'''ight
 ;COM:communication or communicator
-;CRS: '''C'''ou'''rs'''e, indicates the ship's course (heading) in the [[Horizontal Situation Indicator MFD]]
 ;CTD:[[crash to desktop]]
 ;CTRL:Control
@@ Line 95: / Line 78: @@
 #'''C'''rew '''T'''ransfer '''V'''ehicle, a manned spacecraft derived from the [[ATV]], see [[CTV]]
 #'''C'''ompatibility '''T'''est '''V'''an, '''NASA'''
-;CUR: Command button in [[RCS attitude MFD]] to set the programmed attitude to the current attitude
 ;CVEL:
 #[[closing velocity]]
@@ Line 102: / Line 84: @@
 [[#top|Back to top]]
 =D=
-;D3D9:refers to the advanced graphics client in [[Orbiter]]
+;D3D9:refers to the advanced graphics client in [[Orbiter]].
-;Da: Deviation, displayed in [[RCS attitude MFD]] to indicate how many degrees the ship has to go in Roll to reach programmed attitude
-;DCK: command button in [[RCS attitude MFD]] to set the MFD into Docking mode
 ;DDT&E:'''d'''esign, '''d'''evelopment, '''t'''est and '''e'''valuation
-;DEV:'''Dev'''iation, in the [[Horizontal Situation Indicator MFD]], it indicates how far the OBS is adjusted left or right of the radial
 ;DG:[[Delta-glider]]
 ;DG4:Orbiter's stock '''DG'''
@@ Line 114: / Line 93: @@
 ;Dir:'''dir'''ection
 ;Dist:'''dist'''ance
-#Displayed in [[Sync MFD]], distance ship to target
 ;DIV:[[divergent]], i.e. [[yaw]] [[gimbal]] mode.
-;DLng:difference in longitude between ship and target, displayed in [[Sync MFD]]
+;DLng:longitude difference, as seen on the [[synchronise orbit MFD]]
-;DN:
+;DN:[[descending node]]
-#'''Down''', used in [[Map MFD]] when Tracking mode is off and map zoomed in to scroll the map down so you can see farther South
+;DNP:dynamic [[pressure]]
-# Command button in [[RCS attitude MFD]] to change the selected modification up so you can edit it
+;DNS:atmospheric density
-#[[descending node]]
+;DPS:'''D'''ata '''P'''rocessing '''S'''ystem. Term describing the general purpose computers and their interfaces onboard various manned spacecraft.
-;DNP:dynamic [[pressure]], given in Pa
+;DST or Dst:distance (to target)
-#Displayed in [[Surface MFD]] to indicate atmospheric pressure
-;DNS:atmospheric density, given in kg m<sup>-3</sup>, symbol ρ
-#displayed in [[Surface MFD]]
-;DPS:'''D'''ata '''P'''rocessing '''S'''ystem. Term describing the general purpose computers and their interfaces onboard various manned spacecraft
-;Dr: Deviation, displayed in [[RCS attitude MFD]] to indicate how many degrees until the ship reaches pitch and yaw alignment with the programmed attitude
-;DSP: '''D'''i'''sp'''lay, used in [[Map MFD]] to switch between Ground Track Display and Orbital Plane Display
-;DST or Dst:
-#Distance (to target), used in the [[Horizontal Situation Indicator MFD]] to indicate distance to the selected ILS or VOR transmitter
-#Distance, used in [[Orbit MFD]] to select between Rad, ApR, PeR (distance from body center) and Alt, ApA, PeA (distance from body surface)
 ;DTe:time to [[ejection]], as seen on the [[transfer MFD]]
 ;DTi:time to intercept, as seen on the [[transfer MFD]]
-;DTmin:time of arrival difference
+;DTmin:time of arrical difference, as seen on the [[synchronise orbit MFD]]
-#Displayed in [[Sync MFD]] to indicate difference in time between ship and target passing the intersection point
 ;Dv:delta [[velocity]], as seen on the [[transfer MFD]], see also [[Delta-V]]
@@ Line 140: / Line 108: @@
 =E=
-;Ecc:[[eccentricity]] of orbit, displayed in [[Orbit MFD]]
+;Ecc:[[eccentricity]]
 ;ECL:plane of the [[ecliptic]]
 ;ECLSS:'''E'''nvironmental '''c'''ontrol and '''l'''ife '''s'''upport '''s'''ystem
 ;ECSS:'''e'''uropean '''c'''ooperation for '''s'''pace '''s'''tandardization
 ;EELV:Evolved Expendable Launch Vehicle
-;ELS: '''EL'''ements, custom '''S'''elect, used in [[Align MFD]] to select a custom orbital elements to which to align
-;END: command button in [[RCS attitude MFD]] to stop the programmed attitude mode
 ;EQU:plane of the [[equator]]
-;EQU POS: Equatorial position, given as longitude and latitude
-#Displayed in [[Surface MFD]] given as position and rate of change
 ;ESA:[[European Space Agency]]
 ;ESAS:[[w:Exploration Systems Architecture Study|Exploration Systems Architecture Study]]
@@ Line 162: / Line 126: @@
 ;FPS:[[frame rate]] (frames per second), as seen in the [[general information display]]
 ;FRF:'''F'''light '''R'''eadiness '''F'''iring, a launch countdown test of the Shuttle running all except SRB ignition and lift-off.
-;FRM: '''Fr'''a'''m'''e of reference, used in [[Orbit MFD]] to change the orbital display and parameters between Equatorial or Ecliptic
 [[#top|Back to top]]
 =G=
-;G or g:
+;g:a unit of acceleration. 1g equals the gravity acceleration on earths surface, 9.81 m/s²
-#used in [[Orbit MFD]], indicates what fraction of gravity is exerted on the ship by the reference body (0 to 1)
-#unit of acceleration. 1g equals the gravity acceleration on earths surface, 9.81 m/s²
 ;GET:'''G'''round '''E'''lapsed '''T'''ime [http://history.nasa.gov/SP-4029/Apollo_00c_Introduction.htm]
 ;GL:Used often as vehicle name prefix for a [[Delta-glider]]
 ;GLOC:'''G'''ravity-induced '''L'''oss '''o'''f '''C'''onsciousness
 ;GMT:Greenwich Mean Time.See [[w:Universal Time|Universal Time on Wikipedia]]
-;GO: '''Go''', command button in [[RCS attitude MFD]], once the desired orientation and modifications are set, to activate the program
 ;GPDS:[[GPDS|Generic Payload Description System]]
 ;GPS:'''G'''lobal '''P'''ositioning '''S'''ystem
-;GS: [[w:Ground speed|Ground speed]]
+;GS:[[ground speed]]
-#Command button in [[Surface MFD]] to set the speed tape to GS
 ;GTO:[[GTO|'''g'''eostationary '''t'''ransfer '''o'''rbit]]
@@ Line 189: / Line 148: @@
 ;HST:[[Hubble Space Telescope]]
 ;HTO:[[hypothetical transfer orbit]], as seen on the [[transfer MFD]]
-;HUD:[[heads up display]], used in [[Docking MFD]], [[Orbit MFD]], [[Surface MFD]] to copy the current parameters to the HUD
+;HUD:[[heads up display]]
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 =I=
-;IAS:indicated air speed [[w:Indicated airspeed|Indicated airspeed]]
+;IAS:indicated air speed [http://en.wikipedia.org/wiki/Indicated_air_speed]
-#Command button in [[Surface MFD]] to set the speed tape to IAS
+;IDS:[[instrument docking system]]
-;IDS:[[IDS|instrument docking system]], used in [[Docking MFD]]
 ;ILS:
 #[[instrument landing system]]
-#also used in [[Horizontal Situation Indicator MFD]] to indicate which runway at which Spaceport is selected by the NAV system
 #'''I'''nternational '''l'''aunch '''s'''ervices, a US-russian joint venture marketing [[Atlas]] and [[Proton]] launches
-;Inc: [[Inclination]], angular difference between one orbit with respect to another, usually the ecliptic, equatorial, body orbit, or target orbit, displayed in [[Align MFD]], [[Orbit MFD]]
+;Inc:Inclination (http://en.wikipedia.org/wiki/Inclination)
-;INV: Inverse, command button in [[RCS attitude MFD]] to change the programmed attitude to the inverse (retrograde, orbit antinormal, perpendicular out, radial up)
 ;ISP:[[specific impulse]]
 ;ISS:[[International Space Station]]
@@ Line 221: / Line 177: @@
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 =L=
-;LAN:
+;LAN:longitude of [[ascending node]] or local-area network
-#Longitude of the [[ascending node]], used in [[Align MFD]], [[Orbit MFD]]
-#local-area network
 ;LCC:
 #'''l'''aunch '''c'''ontrol '''c'''enter
 #'''l'''ife '''c'''ycle '''c'''ost
 ;LDEF:[[Long Duration Exposure Facility]]
-;LEN: List Length
-#Command button in [[Sync MFD]] to select number of orbits to display (lines 0-18)
 ;LEO:[[Low earth orbit]]
 ;LH2:Liquid Hydrogen
 ;LOCV: Loss of crew and vehicle
 ;LOX:Liquid Oxygen
-;LPe:longitude of [[periapsis]], displayed in [[Orbit MFD]]
+;LPe:longitude of [[periapsis]]
-;L/R:'''L'''eft/'''R'''ight, used in [[Horizontal Situation Indicator MFD]] to switch MFD mode focus to the left or right graphic display
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 =M=
 ;m:metre
-;M:
+;M:Mega (SI prefix for 10<sup>6</sup>). Occasionally mass or [[mach]] number
-#Mega (SI prefix for 10<sup>6</sup>).
-#Mass, given in kg
-#[[mach]] number or multiples of speed of sound in a given medium
-##Used in [[Surface MFD]] ship's speed is given in mach number as well as m/s
 ;MCC:
 #'''m'''id '''c'''ourse '''c'''orrection
@@ Line 254: / Line 201: @@
 ;MET:'''M'''ission '''E'''lapsed '''T'''ime. See [[w:Mission Elapsed Time|Mission Elapsed Time on Wikipedia]].
 ;MFD:'''M'''ulti'''f'''unctional '''D'''isplay, see [[MFD]]
-;MHz: '''M'''ega'''H'''er'''z''', same as the old term megacycles/second, radio and transponder frequency, used in [[COMNAV MFD]]
 ;MJD:[[modified Julian date]]
 ;MLP:[[Mobile Launcher Platform]]
 ;MMOD:'''M'''icro'''m'''eteorites and '''o'''rbital '''d'''ebris
 ;MMU:'''m'''anned '''m'''aneuvering '''u'''nit, see [[MMU]]
-;MnA:[[mean anomaly]], displayed in [[Orbit MFD]]
+;MnA:[[mean anomaly]]
-;MnL:[[mean longitude]], displayed in [[Orbit MFD]]
+;MnL:[[mean longitude]]
-;MOD: used in [[Orbit MFD]] and [[Sync MFD]] to cycle the display between parameters only, orbital display only, or both
 ;m/s:meters per second, the SI base unit of [[velocity]]
 ;MSx:Mission Specialist x
@@ Line 270: / Line 215: @@
 =N=
 ;NAV:
-#Navigatonal receiver,
-##in [[COMNAV MFD]] it is used to identify up to four receivers in the stack
-##in [[Horizontal Situation Indicator MFD]], it is used to select which receiver an HSI display is tuned to
-##in [[RCS attitude MFD]] command button in Docking mode to slave one of the Nav receivers to this MFD
 #navigation
 #[[navigation aid]]
-;NT: '''N'''o '''t'''arget, used in [[Orbit MFD]] to deselect the target
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 =O=
-;OAT:outside air temperature, displayed in [[Surface MFD]] given in Kelvins (K)
+;OAT:outside air temperature
-;Ob:
+;Ob:obliquity of ecliptic (tilt of axis of rotation against plane of ecliptic)
-#Obliquity of ecliptic (tilt of axis of rotation against plane of ecliptic)
-#Orbit, displayed in [[Sync MFD]] indicates how many orbits remaining until rendezvous
-;OB+ and OB-: '''O'''mni'''B'''earing, used to change the offset of the course arrow to left or right of the beam
 ;OBS:[[omni bearing selector]]
 ;OBT:[[orbit]], as seen on the [[orbit MFD]]
@@ Line 290: / Line 227: @@
 ;[[OMP]]:'''O'''rbiter '''M'''ultiplayer '''P'''roject, an ongoing program to create a multiplayer server in Orbiter.
 ;OMS:'''O'''rbital '''M'''aneuvering '''S'''ystem, the 'main engines' of the [[space shuttle]] orbiter
-;OS:[[w:Orbital speed|Orbital speed]]
+;OS:[[orbital speed]]
-#Command button in [[Surface MFD]] to set the speed tape to OS
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@@ Line 302: / Line 238: @@
 ;PDR:'''p'''reliminary '''d'''esign '''r'''eview
 ;PDRS:'''P'''ayload '''D'''eployment and '''R'''etrieval '''S'''ystem, the official name of the robot arm of the Space Shuttle
-;PeA:[[periapsis]] altitude. Altitude of periapsis above the surface of the orbited body, used in [[Orbit MFD]]
+;PeA:[[periapsis]] altitude. Altitude of periapsis above the surface of the orbited body
 ;PeD:[[periapsis]] distance. See PeR.
-;PeR:[[periapsis]] radius. Distance of periapsis from the center of the orbited body, used in [[Orbit MFD]]
+;PeR:[[periapsis]] radius. Distance of periapsis from the center of the orbited body
-;PeT:time to [[periapsis]] in seconds, displayed in [[Orbit MFD]]
+;PeT:time to [[periapsis]] in seconds.
-;PG:
+;PG:[[prograde]]
-#Page, switching displayed pages in an MFD mode, used in [[Align MFD]] and [[Ascent profile MFD]]
-#[[prograde]]
 ;PLT:Pilot
 ;PMI:'''P'''rincipal '''m'''oments of '''i'''nertia, see [[PMI]]
 ;Pos:position
-;PRJ: Projection, used in the [[Orbit MFD]] to switch orbital display between Ecliptic, Equatorial, Ship's orbit, Target orbit
+;PRJ:[[projection]], as seen on the [[orbit MFD]]
 ;PRR:'''p'''reliminary '''r'''equirements '''r'''eview
 ;PSx:Payload Specialist x
@@ Line 326: / Line 260: @@
 #mean radius
 #specific gas constant
-;+R and -R:
-#Command buttons in [[RCS attitude MFD]] (R+) to add a line (pitch, yaw, roll) to the programmed attitude, or R- to remove the last line
-#Command buttons in [[Sync MFD]] to rotate intersection points
 ;r0:atmospheric density at sea level
 ;Rad:
-#Displayed in [[Orbit MFD]] when Radius mode is selected to indicate distance from the center of the body in meters
 #radial distance
 #angular unit ''radians''
-;RAnm:[[true anomaly]] of reference axis, displayed in [[synchronise orbit MFD]]
+;RAnm:[[true anomaly]] of reference axis, as seen on the [[synchronise orbit MFD]]
-;Rate: How fast the current orbital plane is changing, degrees per second, used in [[Align MFD]]
 ;RCS:[[reaction control system]], spacebourne orientation rocket system.
 ;R&D:'''r'''esearch and '''d'''evelopment
 ;RDT&E:'''r'''esearch, '''d'''evelopment, '''t'''esting and '''e'''valuation
-;REF: '''Reference'''
+;REF: '''Reference''', used in Align MFD to select a reference body.
-#used in [[Align MFD]], [[Map MFD]], [[Orbit MFD]] to select a reference body.
-#'''Ref''': Reference displayed in [[Sync MFD]] to switch Reference axis
 ;RG:[[retrograde]]
-;RInc:[[relative inclination]], relative inclination between the ship and target orbits, used in [[Align MFD]] and [[Sync MFD]]
+;RInc:[[relative inclination]], as seen on the [[align orbital plane MFD]]
 ;RKA:Russian Space Agency
 ;RMS:'''R'''emote '''M'''anipulator '''S'''ystem
@@ Line 350: / Line 277: @@
 ;RTFM:'''R'''ead '''t'''he '''f'''ine (or many other '''f'''-words) '''m'''anual, a typical forum answer for questions already answered extensivly in the manual.
 ;RTLS:'''R'''eturn '''t'''o '''l'''aunch '''s'''ite, a [[Space Shuttle]] abort mode.
-;RTN: Return, command button in [[RCS attitude MFD]] to return the display to the Active mode page
 ;RVel:relative [[velocity]]
-#Displayed in [[Sync MFD]], Relative speed between ship and target
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@@ Line 361: / Line 286: @@
 #'''S'''yntetic '''a'''perture '''r'''adar, a [[radar]] mode used for creating navigation maps or detect slowly moving ground vehicles.
 ;S/C: [[spacecraft|'''s'''pace'''c'''raft]]
-;SC< and SC>:'''SC'''an frequency up or down in the currently selected receiver, used in [[COMNAV MFD]]
 ;SDK:Software Development Kit [http://en.wikipedia.org/wiki/SDK]
 ;SDHLV:'''S'''huttle '''D'''erived '''H'''eavy '''L'''aunch '''V'''ehicle, see [[Ares V]]
@@ Line 368: / Line 292: @@
 #'''S'''econdary '''E'''ngine '''C'''ut'''o'''ff
 #'''S'''ustainer '''E'''ngine '''C'''ut'''o'''ff
-;SET: Set, used in [[RCS attitude MFD]] to set the desired attitude
-;SHP: Ship, used in [[Map MFD]] to indicate your ship's name, position, altitude, course of your ship
 ;Sim:
 #simulation time (in seconds), as seen in the [[general information display]]
 #a common abbreviation for "simulator"
+;SHP:[[ship]], as seen on the [[orbit MFD]]
 ;Sh-ToR:ship [[time-on-reference]], as seen on the [[synchronise orbit MFD]]
 ;SI unit: The metric system of measurement, the modern name, see [[SI unit]]
-;SL+ and SL-: '''S'''e'''l'''ect, change which receiver to next or previous receiver to adjust frequency, used in [[COMNAV MFD]]
 ;SLF:shuttle landing facility, see [[Cape Canaveral]]
-;SMa: [[semi-major axis]], used in [[Orbit MFD]]
+;SMa:[[semi-major axis]]
-;SMi:[[semi-minor axis]], used in [[Orbit MFD]]
+;SMi:[[semi-minor axis]]
 ;SRB:'''S'''olid '''R'''ocket '''B'''ooster [http://en.wikipedia.org/wiki/Solid_rocket_booster]
 ;SRTM:'''S'''huttle '''r'''adar '''t'''opography '''m'''ission, see [[SRTM]].
@@ Line 384: / Line 306: @@
 ;SSTO:[[Single_Stage_To_Orbit | Single Stage to Orbit]]
 ;STOVL:Short take-off, vertical landing. As performed by the DG on full fuel employing hover thrusters during takeoff.
-;STP:static [[pressure]], given in Pa
+;STP:static [[pressure]]
-#Displayed in [[Surface MFD]] to indicate atmospheric pressure
 ;STS:'''s'''pace '''t'''ransportation '''s'''ystem, AKA space shuttle, see [[space transportation system]]
-;SUS: command button in [[RCS attitude MFD]] to suspend programmed attitude temporarily
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@@ Line 393: / Line 313: @@
 =T=
-;T:orbit period, measured in seconds, displayed in [[Orbit MFD]]
+;T:orbit period, measured in seconds
 ;TAEM:Terminal Area Energy Management
-;TAS:true air speed [[w:True airspeed|True airspeed]]
+;TAS:true air speed [http://en.wikipedia.org/wiki/True_air_speed]
-#Command button in [[Surface MFD]] to set the speed tape to TAS
 ;TEI:'''T'''rans '''E'''arth '''I'''njection[http://en.wikipedia.org/wiki/Trans_Earth_Injection]
-;TGT:'''T'''ar'''G'''e'''T'''
+;Tgt:target, esp. in [[docking]] mode
-#command button used in [[Align MFD]], [[Docking MFD]], [[Map MFD]], [[Orbit MFD]], and [[Sync MFD]] to select a target
-#used in the [[Map MFD]] display to indicate target name, position, altitude of the target
 ;Tg-ToR:target [[time-on-reference]], as seen on the [[synchronise orbit MFD]]
 ;TKS:russian spacecraft for the Almaz program, see [[TKS]]
@@ Line 408: / Line 325: @@
 ;TLi:intercept longitude, as seen on the [[transfer MFD]]
 ;TLI:Trans Lunar Injection
-;Tn:'''T'''ime to '''n'''ode, used in [[Align MFD]]
+;Tn:time to node, as seen on the [[align orbital plane MFD]]
 ;TOFS:tangential offset [[docking MFD]]
-;ToR: time on reference axis, displayed in [[Sync MFD]] to indicate number of seconds until ship or target passes the intersection point
+;TrA:[[true anomaly]]
-;TrA:[[true anomaly]], displayed in [[Orbit MFD]]
+;TRK:Track ship, as displayed by [[map MFD]]
-;TRK:Track, used in [[map MFD]] to keep the ship centered in the map display
+;TrL:[[true longitude]]
-;TrL:[[true longitude]], displayed in [[Orbit MFD]]
 ;TRL:'''t'''echnology '''r'''eadiness '''l'''evel
 ;Ts:length of siderial day
-;TthA: Estimated thrust time at the ascending node to align planes, used in [[Align MFD]]
+;Tth:predicted thrust time, as seen on the [[align orbital plane MFD]]
-;TthD: Estimated thrust time at the descending node to align planes, used in [[Align MFD]]
 ;TVEL:tangential [[velocity]]
@@ Line 426: / Line 341: @@
 ;UNKS:unknown problems, you are aware of.
 ;UNK-UNKS:unknown problems, you are not aware of.
-;UP:
-#'''UP''', used in [[Map MFD]] when Track mode is off and map is zoomed in to scroll the map up to see farther North
-#Command button in [[RCS attitude MFD]] to change the selected modification up so you can edit it
 ;UT:'''u'''niversal '''t'''ime, GMT. Not to be confused with [[UTC]] (Universial Time Co-ordinated). The latter is based on atomic clocks not astronomy, hence the occasional ''leap-second'' to correct UTC to GMT.
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 =V=
-;+V and -V: Used in [[RCS attitude MFD]] to add or subtract one degree each click the programmed attitude mode
-;VACC: Vertical acceleration, used in [[Surface MFD]] how fast rate of ascent or descent is increasing or decreasing in m/s<sup>2</sup>
 ;VASI:'''V'''isual '''A'''pproach '''S'''lope '''I'''ndicator, the glideslope lighting system ajacent to runways to guide pilots onto the correct angle of glideslope (normally 3 degrees).
 ;VC:
 #virtual cockpit
 #Visual C++, an IDE and C++ compiler by Microsoft.
-;Vel:[[velocity]], displayed in [[Orbit MFD]]
+;Vel:[[velocity]]
-;VOR:
+;VOR:[[very high frequency omnidirectional radio]]
-#[[very high frequency omnidirectional radio]]
-# used in the [[Horizontal Situation Indicator MFD]] to indicate which VOR transmitter is selected by a NAV radio, if it's selected to a VOR transmitter
-;VRR: '''V'''elocity '''R'''adial '''R'''ange, used to manually set the range in the Radial Velocity graph in [[Ascent profile MFD]]
 ;VS:vertical speed
-#Used in [[Surface MFD]] to indicate rate of ascent or descent in meters per second
 ;VSA: [[Virtual Space Agency]]
-;VSI: Vertical Speed Indicator, used in [[Surface MFD]], the VS tape reading rate of ascent or descent, in m/s
 ;VTOL:'''V'''ertical '''T'''ake '''O'''ff and '''L'''anding
-;VTR: '''V'''elocity '''T'''angential '''R'''ange, used to manually set the range in the Tangential Velocity Range graph in [[Ascent profile MFD]]
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@@ Line 457: / Line 361: @@
 ;Wrp:time acceleration factor, seen in the [[general information display]]
 =X=
-;XPDR:[[transponder]], used in [[Docking MFD]]
+;XPDR:[[transponder]]
 =Y=
 ;YSC:Yokohama Science Center
 =Z=
-;ZM+ and ZM-: zoom,used in [[Map MFD]] to zoom the map display in and out
+;ZM:zoom, as seen on the [[map MFD]]
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