Catalog of Bound Variable Names¶
This is the list of special reserved keyword variable names that kOS will interpret to mean something special. If they are used as normal variable names by your kOS script program they may not work. Understanding them and their meaning is crucial to creating effective kOS scripts.
NAMED VESSELS AND BODIES¶
SHIP:
TARGET:
Alias shortcuts for SHIP fields¶
The following are all alias shortcuts for accessing the fields of the SHIP vessel. To see their definition, please consult the Vessel page, as they are all just instances of the standard vessel suffixes.
| Variable | Same as |
|---|---|
| HEADING | Same as SHIP:HEADING |
| PROGRADE | Same as SHIP:PROGRADE |
| RETROGRADE | Same as SHIP:RETROGRADE |
| FACING | Same as SHIP:FACING |
| MAXTHRUST | Same as SHIP:MAXTHRUST |
| VELOCITY | Same as SHIP:VELOCITY |
| GEOPOSITION | Same as SHIP:GEOPOSITION |
| LATITUDE | Same as SHIP:LATITUDE |
| LONGITUDE | Same as SHIP:LONGITUDE |
| UP | Same as SHIP:UP |
| NORTH | Same as SHIP:NORTH |
| BODY | Same as SHIP:BODY |
| ANGULARMOMENTUM | Same as SHIP:ANGULARMOMENTUM |
| ANGULARVEL | Same as SHIP:ANGULARVEL |
| ANGULARVELOCITY | Same as SHIP:ANGULARVEL |
| COMMRANGE | Same as SHIP:COMMRANGE |
| MASS | Same as SHIP:MASS |
| VERTICALSPEED | Same as SHIP:VERTICALSPEED |
| GROUNDSPEED | Same as SHIP:GROUNDSPEED |
| SURFACESPEED | This has been obsoleted as of kOS 0.18.0. Replace it with GROUNDSPEED. |
| AIRSPEED | Same as SHIP:AIRSPEED |
| VESSELNAME | Same as SHIP:VESSELNAME |
| ALTITUDE | Same as SHIP:ALTITUDE |
| APOAPSIS | Same as SHIP:APOAPSIS |
| PERIAPSIS | Same as SHIP:PERIAPSIS |
| SENSORS | Same as SHIP:SENSORS |
| SRFPROGRADE | Same as SHIP:SRFPROGRADE |
| SRFREROGRADE | Same as SHIP:SRFREROGRADE |
| OBT | Same as SHIP:OBT |
| STATUS | Same as SHIP:STATUS |
| SHIPNAME | Same as SHIP:NAME |
Constants (pi, e, etc)¶
Get-only.
The variable constant provides a way to access a few
basic math and physics constants, such as Pi, Euler’s
number, and so on.
Example:
print "Kerbin's circumference: " + (2*constant:pi*Kerbin:radius) + "meters.".
The full list is here: constants page.
Terminal¶
Get-only. terminal returns a terminal structure describing
the attributes of the current terminal screen associated with the
CPU this script is running on.
Stage¶
Get-only. stage returns a stage structure used to count resources
in the current stage. Not to be confused with the COMMAND stage
which triggers the next stage.
NextNode¶
Get-only. nextnode returns the next planned manuever node in the SHIP’s flight plan. Bombs out if no such node exists.
Resource Types¶
Any time there is a resource on the ship it can be queried. The
resources are the values that appear when you click on the upper-right
corner of the screen in the KSP window. 
LIQUIDFUEL
OXIDIZER
ELECTRICCHARGE
MONOPROPELLANT
INTAKEAIR
SOLIDFUEL
All of the above resources can be queried using either the prefix SHIP or STAGE, depending on whether you are trying to query how much is left in the current stage or the entire ship:
How much liquid fuel is left in the entire ship:
PRINT "There is " + SHIP:LIQUIDFUEL + " liquid fuel on the ship.".
How much liquid fuel is left in just the current stage:
PRINT "There is " + STAGE:LIQUIDFUEL + " liquid fuel in this stage.".
How much liquid fuel is left in the target vessel:
PRINT "There is " + TARGET:LIQUIDFUEL + " liquid fuel in the target ship.".
Any other resources that you have added using other mods should be query-able this way, provided that you spell the term exactly as it appears in the resources window.
You can also get a list of all resources, either in SHIP: or STAGE: with the :RESOURCES suffix.
ALT ALIAS¶
The special variable ALT gives you access to a few altitude predictions:
ALT:APOAPSIS
ALT:PERIAPSIS
ALT:RADAR
Further details are found on the ALT page .
ETA ALIAS¶
The special variable ETA gives you access to a few time predictions:
ETA:APOAPSIS
ETA:PERIAPSIS
ETA:TRANSITION
Further details are found on the ETA page .
ENCOUNTER¶
The orbit patch describing the next encounter with a body the current
vessel will enter. If there is no such encounter coming, it will return
the special string “None”. If there is an encounter coming, it will
return an object of type Orbit. (i.e. to obtain the name
of the planet the encounter is with, you can do:
print ENCOUNTER:BODY:NAME., for example.).
BOOLEAN TOGGLE FIELDS:¶
These are variables that behave like boolean flags. They can be True or False, and can be set or toggled using the “ON” and “OFF” and “TOGGLE” commands. Many of these are for action group flags. NOTE ABOUT ACTION GROUP FLAGS: If the boolean flag is for an action group, be aware that each time the user presses the action group keypress, it toggles the action group, so you might need to check for both the change in state from false to true AND the change in state from true to false to see if the key was hit.
| Variable Name | Can Read | Can Set | Description |
|---|---|---|---|
| SAS | yes | yes | (Same as “SAS” indicator on the navball.) |
| RCS | yes | yes | (Same as “RCS” indicator on the navball.) |
| GEAR | yes | yes | Is the GEAR enabled right now? (Note, KSP does some strange things with this flag, like needing to hit it twice the first time). |
| LEGS | yes | yes | Are the landing LEGS extended? (as opposed to GEAR which is for the wheels of a plane.) |
| CHUTES | yes | yes | Are the parachutes extended? (Treats all parachutes as one single unit. Does not activate them individually.) |
| LIGHTS | yes | yes | Are the lights on? (like the “U” key in manual flight.) |
| PANELS | yes | yes | Are the solar panels extended? (Treats all solar panels as one single unit. Does not activate them individually.) |
| BRAKES | yes | yes | Are the brakes on? |
| ABORT | yes | yes | Abort Action Group. |
| AG1 | yes | yes | Action Group 1. |
| AG2 | yes | yes | Action Group 2. |
| AG3 | yes | yes | Action Group 3. |
| AG4 | yes | yes | Action Group 4. |
| AG5 | yes | yes | Action Group 5. |
| AG6 | yes | yes | Action Group 6. |
| AG7 | yes | yes | Action Group 7. |
| AG8 | yes | yes | Action Group 8. |
| AG9 | yes | yes | Action Group 9. |
| AG10 | yes | yes | Action Group 10. |
| AGn | yes | yes | If you have the Action Groups Extended mod installed, you can access its groups the same way, i.e. AG11, AG12, AG13, etc. |
Flight Control¶
There are bound variables used in controlling the flight of a ship, which can be found at the following links:
If you want to let kOS do a lot of the work of aligning to a desired heading for you, use Cooked Control.
If you want your script to manipulate the controls directly (as in “set yaw axis halfway left for a few seconds (using the ‘A’ key)”, then use Raw Control.
If you want to be able to READ what the player is attempting to do while your script is running, and perhaps respond to it, then use Reading the Pilot’s Control settings (i.e reading what the manual input is attempting) (By default your script will override manual piloting attempts, but you can read what the pilot’s controls are set at and make your autopilot take them under advisement - sort of like how a fly-by-wire plane works.)
Controls that must be used with LOCK¶
THROTTLE // Lock to a decimal value between 0 and 1.
STEERING // Lock to a direction, either a Vector or a Direction.
WHEELTHROTTLE // Separate throttle for wheels
WHEELSTEERING // Separate steering system for wheels
Time¶
Time is the simulated amount of time that passed since the beginning of the game’s universe epoch. (A brand new campaign that just started begins at TIME zero.)
TIME is a useful system variable for calculating the passage of time between taking physical measurements (i.e. to calculate how fast a phenomenon is changing in a loop). It returns the KSP simulated time, rather than the actual realtime sitting in the chair playing the game. If everything is running smoothly on a fast computer, one second of simulated time will match one second of real time, but if anything is causing the game to stutter or lag a bit, then the simulated time will be a bit slower than the real time. For any script program trying to calculate physical properties of the KSP universe, the time that matters is the simulated time, which is what TIME returns.
It’s important to be aware of the frozen update nature of the kOS computer when reading TIME.
System Variables¶
This section is about variables that describe the things that are slightly outside the simulated universe of the game and are more about the game’s user interface or the kOS mod itself. They represent things that slightly “break the fourth wall” and let your script access something entirely outside the in-character experience.
PRINT VERSION. // Returns operating system version number. e.g. 0.8.6
PRINT VERSION:MAJOR. // Returns major version number. e.g. 0
PRINT VERSION:MINOR. // Returns minor version number. e.g. 8
PRINT VERSION:BUILD. // Returns build version number. e.g. 6
PRINT SESSIONTIME. // Returns amount of time, in seconds, from vessel load.
NOTE the following important difference:
SESSIONTIME is the time since the last time this vessel was loaded from on-rails into full physics.
TIME is the time since the entire saved game campaign started, in the kerbal universe’s time. i.e. TIME = 0 means a brand new campaign was just started.
Config¶
CONFIG is a special variable name that refers to the configuration settings for the kOS mod, and can be used to set or get various options.
CONFIG has its own page for further details.
MAPVIEW¶
A boolean that is both gettable and settable.
If you query MAPVIEW, it’s true if on the map screen, and false if on the flight view screen. If you SET MAPVIEW, you can cause the game to switch between mapview and flight view or visa versa.
LOADDISTANCE¶
LOADDISTANCE sets the distance from the active vessel at which vessels get removed from the full physics engine and put on-rails, or visa versa. Note that as of KSP 1.0 the stock game supports multiple different load distance settings for different situations such that the value changes depending on where you are. But kOS does not support this at the moment so in kOS if you set the LOADDISTANCE, you are setting it to the same value universally for all situations.
SOLARPRIMEVECTOR¶
Gives the Prime Meridian Vector for the Solar System itself, in
current Ship-Raw XYZ coordinates.
Both the Orbit:LONGITUDEOFASCENDINGNODE orbit suffix and the
Body:ROTATIONANGLE body suffix are expressed in terms of
degree offsets from this Prime Meridian Reference Vector.
What is the Solar Prime Reference Vector?¶
The solar prime vector is an arbitrary vector in space used to measure some orbital parameters that are supposed to remain fixed to space regardless of how the planets underneath the orbit rotate, or where the Sun is. In a sense it can be thought of as the celestial “prime meridian” of the entire solar system, rather than the “prime meridian” of any one particular rotating planet or moon.
In a hypothetical Earthling’s solar system our Kerbal scientists have hypothesized may exist in a galaxy far away, Earthbound astronomers use a reference they called the First Point of Aries, for this purpose.
For Kerbals, it refers to a more arbitrary line in space, pointing at a fixed point in the firmament, also known as the “skybox”.
Addons¶
Get-only. addons is a special variable used to access various extensions
to kOS that are designed to support the features introduced by some other mods. More info can be found on the addons page.
Colors¶
There are several bound variables associated with hardcoded colors such as WHITE, BLACK, RED, etc. See the linked page for the full list.