Parts¶

The following classes allow interaction with a vessels individual parts.

Parts¶

class Parts

Instances of this class are used to interact with the parts of a vessel. An instance can be obtained by calling Vessel.parts.

all

A list of all of the vessels parts.

Attribute: Read-only, cannot be set list(Part) All
root

The vessels root part.

Attribute: Read-only, cannot be set Part All

Note

See the discussion on Trees of Parts.

controlling

The part from which the vessel is controlled.

Attribute: Can be read or written Part All
with_name(name)

A list of parts whose Part.name is name.

Parameters: name (str) – list(Part) All
with_title(title)

A list of all parts whose Part.title is title.

Parameters: title (str) – list(Part) All
with_tag(tag)

A list of all parts whose Part.tag is tag.

Parameters: tag (str) – list(Part) All
with_module(module_name)

A list of all parts that contain a Module whose Module.name is module_name.

Parameters: module_name (str) – list(Part) All
in_stage(stage)

A list of all parts that are activated in the given stage.

Parameters: stage (int) – list(Part) All

Note

See the discussion on Staging.

in_decouple_stage(stage)

A list of all parts that are decoupled in the given stage.

Parameters: stage (int) – list(Part) All

Note

See the discussion on Staging.

modules_with_name(module_name)

A list of modules (combined across all parts in the vessel) whose Module.name is module_name.

Parameters: module_name (str) – list(Module) All
antennas

A list of all antennas in the vessel.

Attribute: Read-only, cannot be set list(Antenna) All
cargo_bays

A list of all cargo bays in the vessel.

Attribute: Read-only, cannot be set list(CargoBay) All
control_surfaces

A list of all control surfaces in the vessel.

Attribute: Read-only, cannot be set list(ControlSurface) All
decouplers

A list of all decouplers in the vessel.

Attribute: Read-only, cannot be set list(Decoupler) All
docking_ports

A list of all docking ports in the vessel.

Attribute: Read-only, cannot be set list(DockingPort) All
engines

A list of all engines in the vessel.

Attribute: Read-only, cannot be set list(Engine) All

Note

This includes any part that generates thrust. This covers many different types of engine, including liquid fuel rockets, solid rocket boosters, jet engines and RCS thrusters.

experiments

A list of all science experiments in the vessel.

Attribute: Read-only, cannot be set list(Experiment) All
fairings

A list of all fairings in the vessel.

Attribute: Read-only, cannot be set list(Fairing) All
intakes

A list of all intakes in the vessel.

Attribute: Read-only, cannot be set list(Intake) All
legs

A list of all landing legs attached to the vessel.

Attribute: Read-only, cannot be set list(Leg) All
launch_clamps

A list of all launch clamps attached to the vessel.

Attribute: Read-only, cannot be set list(LaunchClamp) All
lights

A list of all lights in the vessel.

Attribute: Read-only, cannot be set list(Light) All
parachutes

A list of all parachutes in the vessel.

Attribute: Read-only, cannot be set list(Parachute) All
radiators

A list of all radiators in the vessel.

Attribute: Read-only, cannot be set list(Radiator) All
rcs

A list of all RCS blocks/thrusters in the vessel.

Attribute: Read-only, cannot be set list(RCS) All
reaction_wheels

A list of all reaction wheels in the vessel.

Attribute: Read-only, cannot be set list(ReactionWheel) All
resource_converters

A list of all resource converters in the vessel.

Attribute: Read-only, cannot be set list(ResourceConverter) All
resource_harvesters

A list of all resource harvesters in the vessel.

Attribute: Read-only, cannot be set list(ResourceHarvester) All
sensors

A list of all sensors in the vessel.

Attribute: Read-only, cannot be set list(Sensor) All
solar_panels

A list of all solar panels in the vessel.

Attribute: Read-only, cannot be set list(SolarPanel) All
wheels

A list of all wheels in the vessel.

Attribute: Read-only, cannot be set list(Wheel) All

Part¶

class Part

Represents an individual part. Vessels are made up of multiple parts. Instances of this class can be obtained by several methods in Parts.

name

Internal name of the part, as used in part cfg files. For example “Mark1-2Pod”.

Attribute: Read-only, cannot be set str All
title

Title of the part, as shown when the part is right clicked in-game. For example “Mk1-2 Command Pod”.

Attribute: Read-only, cannot be set str All
tag

The name tag for the part. Can be set to a custom string using the in-game user interface.

Attribute: Can be read or written str All

Note

This string is shared with kOS if it is installed.

highlighted

Whether the part is highlighted.

Attribute: Can be read or written bool All
highlight_color

The color used to highlight the part, as an RGB triple.

Attribute: Can be read or written tuple(double, double, double) All
cost

The cost of the part, in units of funds.

Attribute: Read-only, cannot be set double All
vessel

The vessel that contains this part.

Attribute: Read-only, cannot be set Vessel All
parent

The parts parent. Returns None if the part does not have a parent. This, in combination with Part.children, can be used to traverse the vessels parts tree.

Attribute: Read-only, cannot be set Part All

Note

See the discussion on Trees of Parts.

children

The parts children. Returns an empty list if the part has no children. This, in combination with Part.parent, can be used to traverse the vessels parts tree.

Attribute: Read-only, cannot be set list(Part) All

Note

See the discussion on Trees of Parts.

axially_attached

Whether the part is axially attached to its parent, i.e. on the top or bottom of its parent. If the part has no parent, returns False.

Attribute: Read-only, cannot be set bool All

Note

See the discussion on Attachment Modes.

radially_attached

Whether the part is radially attached to its parent, i.e. on the side of its parent. If the part has no parent, returns False.

Attribute: Read-only, cannot be set bool All

Note

See the discussion on Attachment Modes.

stage

The stage in which this part will be activated. Returns -1 if the part is not activated by staging.

Attribute: Read-only, cannot be set int All

Note

See the discussion on Staging.

decouple_stage

The stage in which this part will be decoupled. Returns -1 if the part is never decoupled from the vessel.

Attribute: Read-only, cannot be set int All

Note

See the discussion on Staging.

massless

Whether the part is massless.

Attribute: Read-only, cannot be set bool All
mass

The current mass of the part, including resources it contains, in kilograms. Returns zero if the part is massless.

Attribute: Read-only, cannot be set double All
dry_mass

The mass of the part, not including any resources it contains, in kilograms. Returns zero if the part is massless.

Attribute: Read-only, cannot be set double All
shielded

Whether the part is shielded from the exterior of the vessel, for example by a fairing.

Attribute: Read-only, cannot be set bool All
dynamic_pressure

The dynamic pressure acting on the part, in Pascals.

Attribute: Read-only, cannot be set float All
impact_tolerance

The impact tolerance of the part, in meters per second.

Attribute: Read-only, cannot be set double All
temperature

Temperature of the part, in Kelvin.

Attribute: Read-only, cannot be set double All
skin_temperature

Temperature of the skin of the part, in Kelvin.

Attribute: Read-only, cannot be set double All
max_temperature

Maximum temperature that the part can survive, in Kelvin.

Attribute: Read-only, cannot be set double All
max_skin_temperature

Maximum temperature that the skin of the part can survive, in Kelvin.

Attribute: Read-only, cannot be set double All
thermal_mass

A measure of how much energy it takes to increase the internal temperature of the part, in Joules per Kelvin.

Attribute: Read-only, cannot be set float All
thermal_skin_mass

A measure of how much energy it takes to increase the skin temperature of the part, in Joules per Kelvin.

Attribute: Read-only, cannot be set float All
thermal_resource_mass

A measure of how much energy it takes to increase the temperature of the resources contained in the part, in Joules per Kelvin.

Attribute: Read-only, cannot be set float All
thermal_conduction_flux

The rate at which heat energy is conducting into or out of the part via contact with other parts. Measured in energy per unit time, or power, in Watts. A positive value means the part is gaining heat energy, and negative means it is losing heat energy.

Attribute: Read-only, cannot be set float All
thermal_convection_flux

The rate at which heat energy is convecting into or out of the part from the surrounding atmosphere. Measured in energy per unit time, or power, in Watts. A positive value means the part is gaining heat energy, and negative means it is losing heat energy.

Attribute: Read-only, cannot be set float All
thermal_radiation_flux

The rate at which heat energy is radiating into or out of the part from the surrounding environment. Measured in energy per unit time, or power, in Watts. A positive value means the part is gaining heat energy, and negative means it is losing heat energy.

Attribute: Read-only, cannot be set float All
thermal_internal_flux

The rate at which heat energy is begin generated by the part. For example, some engines generate heat by combusting fuel. Measured in energy per unit time, or power, in Watts. A positive value means the part is gaining heat energy, and negative means it is losing heat energy.

Attribute: Read-only, cannot be set float All
thermal_skin_to_internal_flux

The rate at which heat energy is transferring between the part’s skin and its internals. Measured in energy per unit time, or power, in Watts. A positive value means the part’s internals are gaining heat energy, and negative means its skin is gaining heat energy.

Attribute: Read-only, cannot be set float All
resources

A Resources object for the part.

Attribute: Read-only, cannot be set Resources All
crossfeed

Whether this part is crossfeed capable.

Attribute: Read-only, cannot be set bool All
is_fuel_line

Whether this part is a fuel line.

Attribute: Read-only, cannot be set bool All
fuel_lines_from

The parts that are connected to this part via fuel lines, where the direction of the fuel line is into this part.

Attribute: Read-only, cannot be set list(Part) All

Note

See the discussion on Fuel Lines.

fuel_lines_to

The parts that are connected to this part via fuel lines, where the direction of the fuel line is out of this part.

Attribute: Read-only, cannot be set list(Part) All

Note

See the discussion on Fuel Lines.

modules

The modules for this part.

Attribute: Read-only, cannot be set list(Module) All
antenna

A Antenna if the part is an antenna, otherwise None.

Attribute: Read-only, cannot be set Antenna All
cargo_bay

A CargoBay if the part is a cargo bay, otherwise None.

Attribute: Read-only, cannot be set CargoBay All
control_surface

A ControlSurface if the part is an aerodynamic control surface, otherwise None.

Attribute: Read-only, cannot be set ControlSurface All
decoupler

A Decoupler if the part is a decoupler, otherwise None.

Attribute: Read-only, cannot be set Decoupler All
docking_port

A DockingPort if the part is a docking port, otherwise None.

Attribute: Read-only, cannot be set DockingPort All
engine

An Engine if the part is an engine, otherwise None.

Attribute: Read-only, cannot be set Engine All
experiment

An Experiment if the part is a science experiment, otherwise None.

Attribute: Read-only, cannot be set Experiment All
fairing

A Fairing if the part is a fairing, otherwise None.

Attribute: Read-only, cannot be set Fairing All
intake

An Intake if the part is an intake, otherwise None.

Attribute: Read-only, cannot be set Intake All

Note

This includes any part that generates thrust. This covers many different types of engine, including liquid fuel rockets, solid rocket boosters and jet engines. For RCS thrusters see RCS.

leg

A Leg if the part is a landing leg, otherwise None.

Attribute: Read-only, cannot be set Leg All
launch_clamp

A LaunchClamp if the part is a launch clamp, otherwise None.

Attribute: Read-only, cannot be set LaunchClamp All
light

A Light if the part is a light, otherwise None.

Attribute: Read-only, cannot be set Light All
parachute

A Parachute if the part is a parachute, otherwise None.

Attribute: Read-only, cannot be set Parachute All
radiator

A Radiator if the part is a radiator, otherwise None.

Attribute: Read-only, cannot be set Radiator All
rcs

A RCS if the part is an RCS block/thruster, otherwise None.

Attribute: Read-only, cannot be set RCS All
reaction_wheel

A ReactionWheel if the part is a reaction wheel, otherwise None.

Attribute: Read-only, cannot be set ReactionWheel All
resource_converter

A ResourceConverter if the part is a resource converter, otherwise None.

Attribute: Read-only, cannot be set ResourceConverter All
resource_harvester

A ResourceHarvester if the part is a resource harvester, otherwise None.

Attribute: Read-only, cannot be set ResourceHarvester All
sensor

A Sensor if the part is a sensor, otherwise None.

Attribute: Read-only, cannot be set Sensor All
solar_panel

A SolarPanel if the part is a solar panel, otherwise None.

Attribute: Read-only, cannot be set SolarPanel All
wheel

A Wheel if the part is a wheel, otherwise None.

Attribute: Read-only, cannot be set Wheel All
position(reference_frame)

The position of the part in the given reference frame.

Parameters: reference_frame (ReferenceFrame) – The reference frame that the returned position vector is in. The position as a vector. tuple(double, double, double) All

Note

This is a fixed position in the part, defined by the parts model. It s not necessarily the same as the parts center of mass. Use Part.center_of_mass() to get the parts center of mass.

center_of_mass(reference_frame)

The position of the parts center of mass in the given reference frame. If the part is physicsless, this is equivalent to Part.position().

Parameters: reference_frame (ReferenceFrame) – The reference frame that the returned position vector is in. The position as a vector. tuple(double, double, double) All
bounding_box(reference_frame)

The axis-aligned bounding box of the part in the given reference frame.

Parameters: reference_frame (ReferenceFrame) – The reference frame that the returned position vectors are in. The positions of the minimum and maximum vertices of the box, as position vectors. tuple(tuple(double, double, double), tuple(double, double, double)) All

Note

This is computed from the collision mesh of the part. If the part is not collidable, the box has zero volume and is centered on the Part.position() of the part.

direction(reference_frame)

The direction the part points in, in the given reference frame.

Parameters: reference_frame (ReferenceFrame) – The reference frame that the returned direction is in. The direction as a unit vector. tuple(double, double, double) All
velocity(reference_frame)

The linear velocity of the part in the given reference frame.

Parameters: reference_frame (ReferenceFrame) – The reference frame that the returned velocity vector is in. The velocity as a vector. The vector points in the direction of travel, and its magnitude is the speed of the body in meters per second. tuple(double, double, double) All
rotation(reference_frame)

The rotation of the part, in the given reference frame.

Parameters: reference_frame (ReferenceFrame) – The reference frame that the returned rotation is in. The rotation as a quaternion of the form $$(x, y, z, w)$$. tuple(double, double, double, double) All
moment_of_inertia

The moment of inertia of the part in $$kg.m^2$$ around its center of mass in the parts reference frame (ReferenceFrame).

Attribute: Read-only, cannot be set tuple(double, double, double) All
inertia_tensor

The inertia tensor of the part in the parts reference frame (ReferenceFrame). Returns the 3x3 matrix as a list of elements, in row-major order.

Attribute: Read-only, cannot be set list(double) All
reference_frame

The reference frame that is fixed relative to this part, and centered on a fixed position within the part, defined by the parts model.

• The origin is at the position of the part, as returned by Part.position().
• The axes rotate with the part.
• The x, y and z axis directions depend on the design of the part.
Attribute: Read-only, cannot be set ReferenceFrame All

Note

For docking port parts, this reference frame is not necessarily equivalent to the reference frame for the docking port, returned by DockingPort.reference_frame.

Mk1 Command Pod reference frame origin and axes

center_of_mass_reference_frame

The reference frame that is fixed relative to this part, and centered on its center of mass.

• The origin is at the center of mass of the part, as returned by Part.center_of_mass().
• The axes rotate with the part.
• The x, y and z axis directions depend on the design of the part.
Attribute: Read-only, cannot be set ReferenceFrame All

Note

For docking port parts, this reference frame is not necessarily equivalent to the reference frame for the docking port, returned by DockingPort.reference_frame.

add_force(force, position, reference_frame)

Exert a constant force on the part, acting at the given position.

Parameters: force (tuple) – A vector pointing in the direction that the force acts, with its magnitude equal to the strength of the force in Newtons. position (tuple) – The position at which the force acts, as a vector. reference_frame (ReferenceFrame) – The reference frame that the force and position are in. An object that can be used to remove or modify the force. Force All
instantaneous_force(force, position, reference_frame)

Exert an instantaneous force on the part, acting at the given position.

Parameters: force (tuple) – A vector pointing in the direction that the force acts, with its magnitude equal to the strength of the force in Newtons. position (tuple) – The position at which the force acts, as a vector. reference_frame (ReferenceFrame) – The reference frame that the force and position are in. All

Note

The force is applied instantaneously in a single physics update.

class Force

Obtained by calling Part.add_force().

part

The part that this force is applied to.

Attribute: Read-only, cannot be set Part All
force_vector

The force vector, in Newtons.

Attribute: Can be read or written A vector pointing in the direction that the force acts, with its magnitude equal to the strength of the force in Newtons. tuple(double, double, double) All
position

The position at which the force acts, in reference frame ReferenceFrame.

Attribute: Can be read or written The position as a vector. tuple(double, double, double) All
reference_frame

The reference frame of the force vector and position.

Attribute: Can be read or written ReferenceFrame All
remove()

Remove the force.

Game Scenes: All

Module¶

class Module

This can be used to interact with a specific part module. This includes part modules in stock KSP, and those added by mods.

In KSP, each part has zero or more PartModules associated with it. Each one contains some of the functionality of the part. For example, an engine has a “ModuleEngines” part module that contains all the functionality of an engine.

name

Name of the PartModule. For example, “ModuleEngines”.

Attribute: Read-only, cannot be set str All
part

The part that contains this module.

Attribute: Read-only, cannot be set Part All
fields

The modules field names and their associated values, as a dictionary. These are the values visible in the right-click menu of the part.

Attribute: Read-only, cannot be set dict(str, str) All
has_field(name)

Returns True if the module has a field with the given name.

Parameters: name (str) – Name of the field. bool All
get_field(name)

Returns the value of a field.

Parameters: name (str) – Name of the field. str All
set_field_int(name, value)

Set the value of a field to the given integer number.

Parameters: name (str) – Name of the field. value (int) – Value to set. All
set_field_float(name, value)

Set the value of a field to the given floating point number.

Parameters: name (str) – Name of the field. value (float) – Value to set. All
set_field_string(name, value)

Set the value of a field to the given string.

Parameters: name (str) – Name of the field. value (str) – Value to set. All
reset_field(name)

Set the value of a field to its original value.

Parameters: name (str) – Name of the field. All
events

A list of the names of all of the modules events. Events are the clickable buttons visible in the right-click menu of the part.

Attribute: Read-only, cannot be set list(str) All
has_event(name)

True if the module has an event with the given name.

Parameters: name (str) – bool All
trigger_event(name)

Trigger the named event. Equivalent to clicking the button in the right-click menu of the part.

Parameters: name (str) – All
actions

A list of all the names of the modules actions. These are the parts actions that can be assigned to action groups in the in-game editor.

Attribute: Read-only, cannot be set list(str) All
has_action(name)

True if the part has an action with the given name.

Parameters: name (str) – bool All
set_action(name[, value = True])

Set the value of an action with the given name.

Parameters: name (str) – value (bool) – All

Specific Types of Part¶

The following classes provide functionality for specific types of part.

Antenna¶

class Antenna

An antenna. Obtained by calling Part.antenna.

part

The part object for this antenna.

Attribute: Read-only, cannot be set Part All
state

The current state of the antenna.

Attribute: Read-only, cannot be set AntennaState All
deployable

Whether the antenna is deployable.

Attribute: Read-only, cannot be set bool All
deployed

Whether the antenna is deployed.

Attribute: Can be read or written bool All

Note

Fixed antennas are always deployed. Returns an error if you try to deploy a fixed antenna.

can_transmit

Whether data can be transmitted by this antenna.

Attribute: Read-only, cannot be set bool All
transmit()

Transmit data.

Game Scenes: All
cancel()

Cancel current transmission of data.

Game Scenes: All
allow_partial

Whether partial data transmission is permitted.

Attribute: Can be read or written bool All
power

The power of the antenna.

Attribute: Read-only, cannot be set double All
combinable

Whether the antenna can be combined with other antennae on the vessel to boost the power.

Attribute: Read-only, cannot be set bool All
combinable_exponent

Exponent used to calculate the combined power of multiple antennae on a vessel.

Attribute: Read-only, cannot be set double All
packet_interval

Interval between sending packets in seconds.

Attribute: Read-only, cannot be set float All
packet_size

Amount of data sent per packet in Mits.

Attribute: Read-only, cannot be set float All
packet_resource_cost

Units of electric charge consumed per packet sent.

Attribute: Read-only, cannot be set double All
class AntennaState

The state of an antenna. See Antenna.state.

deployed

Antenna is fully deployed.

retracted

Antenna is fully retracted.

deploying

Antenna is being deployed.

retracting

Antenna is being retracted.

broken

Antenna is broken.

Cargo Bay¶

class CargoBay

A cargo bay. Obtained by calling Part.cargo_bay.

part

The part object for this cargo bay.

Attribute: Read-only, cannot be set Part All
state

The state of the cargo bay.

Attribute: Read-only, cannot be set CargoBayState All
open

Whether the cargo bay is open.

Attribute: Can be read or written bool All
class CargoBayState

The state of a cargo bay. See CargoBay.state.

open

Cargo bay is fully open.

closed

Cargo bay closed and locked.

opening

Cargo bay is opening.

closing

Cargo bay is closing.

Control Surface¶

class ControlSurface

An aerodynamic control surface. Obtained by calling Part.control_surface.

part

The part object for this control surface.

Attribute: Read-only, cannot be set Part All
pitch_enabled

Whether the control surface has pitch control enabled.

Attribute: Can be read or written bool All
yaw_enabled

Whether the control surface has yaw control enabled.

Attribute: Can be read or written bool All
roll_enabled

Whether the control surface has roll control enabled.

Attribute: Can be read or written bool All
authority_limiter

The authority limiter for the control surface, which controls how far the control surface will move.

Attribute: Can be read or written float All
inverted

Whether the control surface movement is inverted.

Attribute: Can be read or written bool All
deployed

Whether the control surface has been fully deployed.

Attribute: Can be read or written bool All
surface_area

Surface area of the control surface in $$m^2$$.

Attribute: Read-only, cannot be set float All
available_torque

The available torque, in Newton meters, that can be produced by this control surface, in the positive and negative pitch, roll and yaw axes of the vessel. These axes correspond to the coordinate axes of the Vessel.reference_frame.

Attribute: Read-only, cannot be set tuple(tuple(double, double, double), tuple(double, double, double)) All

Decoupler¶

class Decoupler

A decoupler. Obtained by calling Part.decoupler

part

The part object for this decoupler.

Attribute: Read-only, cannot be set Part All
decouple()

Fires the decoupler. Returns the new vessel created when the decoupler fires. Throws an exception if the decoupler has already fired.

Return type: Vessel All

Note

When called, the active vessel may change. It is therefore possible that, after calling this function, the object(s) returned by previous call(s) to active_vessel no longer refer to the active vessel.

decoupled

Whether the decoupler has fired.

Attribute: Read-only, cannot be set bool All
staged

Whether the decoupler is enabled in the staging sequence.

Attribute: Read-only, cannot be set bool All
impulse

The impulse that the decoupler imparts when it is fired, in Newton seconds.

Attribute: Read-only, cannot be set float All

Docking Port¶

class DockingPort

A docking port. Obtained by calling Part.docking_port

part

The part object for this docking port.

Attribute: Read-only, cannot be set Part All
state

The current state of the docking port.

Attribute: Read-only, cannot be set DockingPortState All
docked_part

The part that this docking port is docked to. Returns None if this docking port is not docked to anything.

Attribute: Read-only, cannot be set Part All
undock()

Undocks the docking port and returns the new Vessel that is created. This method can be called for either docking port in a docked pair. Throws an exception if the docking port is not docked to anything.

Return type: Vessel All

Note

When called, the active vessel may change. It is therefore possible that, after calling this function, the object(s) returned by previous call(s) to active_vessel no longer refer to the active vessel.

reengage_distance

The distance a docking port must move away when it undocks before it becomes ready to dock with another port, in meters.

Attribute: Read-only, cannot be set float All
has_shield

Whether the docking port has a shield.

Attribute: Read-only, cannot be set bool All
shielded

The state of the docking ports shield, if it has one.

Returns True if the docking port has a shield, and the shield is closed. Otherwise returns False. When set to True, the shield is closed, and when set to False the shield is opened. If the docking port does not have a shield, setting this attribute has no effect.

Attribute: Can be read or written bool All
position(reference_frame)

The position of the docking port, in the given reference frame.

Parameters: reference_frame (ReferenceFrame) – The reference frame that the returned position vector is in. The position as a vector. tuple(double, double, double) All
direction(reference_frame)

The direction that docking port points in, in the given reference frame.

Parameters: reference_frame (ReferenceFrame) – The reference frame that the returned direction is in. The direction as a unit vector. tuple(double, double, double) All
rotation(reference_frame)

The rotation of the docking port, in the given reference frame.

Parameters: reference_frame (ReferenceFrame) – The reference frame that the returned rotation is in. The rotation as a quaternion of the form $$(x, y, z, w)$$. tuple(double, double, double, double) All
reference_frame

The reference frame that is fixed relative to this docking port, and oriented with the port.

• The origin is at the position of the docking port.
• The axes rotate with the docking port.
• The x-axis points out to the right side of the docking port.
• The y-axis points in the direction the docking port is facing.
• The z-axis points out of the bottom off the docking port.
Attribute: Read-only, cannot be set ReferenceFrame All

Note

This reference frame is not necessarily equivalent to the reference frame for the part, returned by Part.reference_frame.

Docking port reference frame origin and axes

Inline docking port reference frame origin and axes

class DockingPortState

The state of a docking port. See DockingPort.state.

ready

The docking port is ready to dock to another docking port.

docked

The docking port is docked to another docking port, or docked to another part (from the VAB/SPH).

docking

The docking port is very close to another docking port, but has not docked. It is using magnetic force to acquire a solid dock.

undocking

The docking port has just been undocked from another docking port, and is disabled until it moves away by a sufficient distance (DockingPort.reengage_distance).

shielded

The docking port has a shield, and the shield is closed.

moving

The docking ports shield is currently opening/closing.

Engine¶

class Engine

An engine, including ones of various types. For example liquid fuelled gimballed engines, solid rocket boosters and jet engines. Obtained by calling Part.engine.

Note

For RCS thrusters Part.rcs.

part

The part object for this engine.

Attribute: Read-only, cannot be set Part All
active

Whether the engine is active. Setting this attribute may have no effect, depending on Engine.can_shutdown and Engine.can_restart.

Attribute: Can be read or written bool All
thrust

The current amount of thrust being produced by the engine, in Newtons.

Attribute: Read-only, cannot be set float All
available_thrust

The amount of thrust, in Newtons, that would be produced by the engine when activated and with its throttle set to 100%. Returns zero if the engine does not have any fuel. Takes the engine’s current Engine.thrust_limit and atmospheric conditions into account.

Attribute: Read-only, cannot be set float All
max_thrust

The amount of thrust, in Newtons, that would be produced by the engine when activated and fueled, with its throttle and throttle limiter set to 100%.

Attribute: Read-only, cannot be set float All
max_vacuum_thrust

The maximum amount of thrust that can be produced by the engine in a vacuum, in Newtons. This is the amount of thrust produced by the engine when activated, Engine.thrust_limit is set to 100%, the main vessel’s throttle is set to 100% and the engine is in a vacuum.

Attribute: Read-only, cannot be set float All
thrust_limit

The thrust limiter of the engine. A value between 0 and 1. Setting this attribute may have no effect, for example the thrust limit for a solid rocket booster cannot be changed in flight.

Attribute: Can be read or written float All
thrusters

The components of the engine that generate thrust.

Attribute: Read-only, cannot be set list(Thruster) All

Note

For example, this corresponds to the rocket nozzel on a solid rocket booster, or the individual nozzels on a RAPIER engine. The overall thrust produced by the engine, as reported by Engine.available_thrust, Engine.max_thrust and others, is the sum of the thrust generated by each thruster.

specific_impulse

The current specific impulse of the engine, in seconds. Returns zero if the engine is not active.

Attribute: Read-only, cannot be set float All
vacuum_specific_impulse

The vacuum specific impulse of the engine, in seconds.

Attribute: Read-only, cannot be set float All
kerbin_sea_level_specific_impulse

The specific impulse of the engine at sea level on Kerbin, in seconds.

Attribute: Read-only, cannot be set float All
propellant_names

The names of the propellants that the engine consumes.

Attribute: Read-only, cannot be set list(str) All
propellant_ratios

The ratio of resources that the engine consumes. A dictionary mapping resource names to the ratio at which they are consumed by the engine.

Attribute: Read-only, cannot be set dict(str, float) All

Note

For example, if the ratios are 0.6 for LiquidFuel and 0.4 for Oxidizer, then for every 0.6 units of LiquidFuel that the engine burns, it will burn 0.4 units of Oxidizer.

propellants

The propellants that the engine consumes.

Attribute: Read-only, cannot be set list(Propellant) All
has_fuel

Whether the engine has any fuel available.

Attribute: Read-only, cannot be set bool All

Note

The engine must be activated for this property to update correctly.

throttle

The current throttle setting for the engine. A value between 0 and 1. This is not necessarily the same as the vessel’s main throttle setting, as some engines take time to adjust their throttle (such as jet engines).

Attribute: Read-only, cannot be set float All
throttle_locked

Whether the Control.throttle affects the engine. For example, this is True for liquid fueled rockets, and False for solid rocket boosters.

Attribute: Read-only, cannot be set bool All
can_restart

Whether the engine can be restarted once shutdown. If the engine cannot be shutdown, returns False. For example, this is True for liquid fueled rockets and False for solid rocket boosters.

Attribute: Read-only, cannot be set bool All
can_shutdown

Whether the engine can be shutdown once activated. For example, this is True for liquid fueled rockets and False for solid rocket boosters.

Attribute: Read-only, cannot be set bool All
has_modes

Whether the engine has multiple modes of operation.

Attribute: Read-only, cannot be set bool All
mode

The name of the current engine mode.

Attribute: Can be read or written str All
modes

The available modes for the engine. A dictionary mapping mode names to Engine objects.

Attribute: Read-only, cannot be set dict(str, Engine) All
toggle_mode()

Toggle the current engine mode.

Game Scenes: All
auto_mode_switch

Whether the engine will automatically switch modes.

Attribute: Can be read or written bool All
gimballed

Whether the engine is gimballed.

Attribute: Read-only, cannot be set bool All
gimbal_range

The range over which the gimbal can move, in degrees. Returns 0 if the engine is not gimballed.

Attribute: Read-only, cannot be set float All
gimbal_locked

Whether the engines gimbal is locked in place. Setting this attribute has no effect if the engine is not gimballed.

Attribute: Can be read or written bool All
gimbal_limit

The gimbal limiter of the engine. A value between 0 and 1. Returns 0 if the gimbal is locked.

Attribute: Can be read or written float All
available_torque

The available torque, in Newton meters, that can be produced by this engine, in the positive and negative pitch, roll and yaw axes of the vessel. These axes correspond to the coordinate axes of the Vessel.reference_frame. Returns zero if the engine is inactive, or not gimballed.

Attribute: Read-only, cannot be set tuple(tuple(double, double, double), tuple(double, double, double)) All
class Propellant

A propellant for an engine. Obtains by calling Engine.propellants.

name

The name of the propellant.

Attribute: Read-only, cannot be set str All
current_amount

The current amount of propellant.

Attribute: Read-only, cannot be set double All
current_requirement

The required amount of propellant.

Attribute: Read-only, cannot be set double All
total_resource_available

The total amount of the underlying resource currently reachable given resource flow rules.

Attribute: Read-only, cannot be set double All
total_resource_capacity

The total vehicle capacity for the underlying propellant resource, restricted by resource flow rules.

Attribute: Read-only, cannot be set double All
ignore_for_isp

If this propellant should be ignored when calculating required mass flow given specific impulse.

Attribute: Read-only, cannot be set bool All
ignore_for_thrust_curve

If this propellant should be ignored for thrust curve calculations.

Attribute: Read-only, cannot be set bool All
draw_stack_gauge

If this propellant has a stack gauge or not.

Attribute: Read-only, cannot be set bool All
is_deprived

If this propellant is deprived.

Attribute: Read-only, cannot be set bool All
ratio

The propellant ratio.

Attribute: Read-only, cannot be set float All

Experiment¶

class Experiment

Obtained by calling Part.experiment.

part

The part object for this experiment.

Attribute: Read-only, cannot be set Part All
run()

Run the experiment.

Game Scenes: All
transmit()

Transmit all experimental data contained by this part.

Game Scenes: All
dump()

Dump the experimental data contained by the experiment.

Game Scenes: All
reset()

Reset the experiment.

Game Scenes: All
deployed

Whether the experiment has been deployed.

Attribute: Read-only, cannot be set bool All
rerunnable

Whether the experiment can be re-run.

Attribute: Read-only, cannot be set bool All
inoperable

Whether the experiment is inoperable.

Attribute: Read-only, cannot be set bool All
has_data

Whether the experiment contains data.

Attribute: Read-only, cannot be set bool All
data

The data contained in this experiment.

Attribute: Read-only, cannot be set list(ScienceData) All
biome

The name of the biome the experiment is currently in.

Attribute: Read-only, cannot be set str All
available

Determines if the experiment is available given the current conditions.

Attribute: Read-only, cannot be set bool All
science_subject

Containing information on the corresponding specific science result for the current conditions. Returns None if the experiment is unavailable.

Attribute: Read-only, cannot be set ScienceSubject All
class ScienceData

Obtained by calling Experiment.data.

data_amount

Data amount.

Attribute: Read-only, cannot be set float All
science_value

Science value.

Attribute: Read-only, cannot be set float All
transmit_value

Transmit value.

Attribute: Read-only, cannot be set float All
class ScienceSubject

Obtained by calling Experiment.science_subject.

title

Title of science subject, displayed in science archives

Attribute: Read-only, cannot be set str All
is_complete

Whether the experiment has been completed.

Attribute: Read-only, cannot be set bool All
science

Amount of science already earned from this subject, not updated until after transmission/recovery.

Attribute: Read-only, cannot be set float All
science_cap

Total science allowable for this subject.

Attribute: Read-only, cannot be set float All
data_scale

Multiply science value by this to determine data amount in mits.

Attribute: Read-only, cannot be set float All
subject_value

Multiplier for specific Celestial Body/Experiment Situation combination.

Attribute: Read-only, cannot be set float All
scientific_value

Diminishing value multiplier for decreasing the science value returned from repeated experiments.

Attribute: Read-only, cannot be set float All

Fairing¶

class Fairing

A fairing. Obtained by calling Part.fairing.

part

The part object for this fairing.

Attribute: Read-only, cannot be set Part All
jettison()

Jettison the fairing. Has no effect if it has already been jettisoned.

Game Scenes: All
jettisoned

Whether the fairing has been jettisoned.

Attribute: Read-only, cannot be set bool All

Intake¶

class Intake

An air intake. Obtained by calling Part.intake.

part

The part object for this intake.

Attribute: Read-only, cannot be set Part All
open

Whether the intake is open.

Attribute: Can be read or written bool All
speed

Speed of the flow into the intake, in $$m/s$$.

Attribute: Read-only, cannot be set float All
flow

The rate of flow into the intake, in units of resource per second.

Attribute: Read-only, cannot be set float All
area

The area of the intake’s opening, in square meters.

Attribute: Read-only, cannot be set float All

Leg¶

class Leg

A landing leg. Obtained by calling Part.leg.

part

The part object for this landing leg.

Attribute: Read-only, cannot be set Part All
state

The current state of the landing leg.

Attribute: Read-only, cannot be set LegState All
deployable

Whether the leg is deployable.

Attribute: Read-only, cannot be set bool All
deployed

Whether the landing leg is deployed.

Attribute: Can be read or written bool All

Note

Fixed landing legs are always deployed. Returns an error if you try to deploy fixed landing gear.

is_grounded

Returns whether the leg is touching the ground.

Attribute: Read-only, cannot be set bool All
class LegState

The state of a landing leg. See Leg.state.

deployed

Landing leg is fully deployed.

retracted

Landing leg is fully retracted.

deploying

Landing leg is being deployed.

retracting

Landing leg is being retracted.

broken

Landing leg is broken.

Launch Clamp¶

class LaunchClamp

A launch clamp. Obtained by calling Part.launch_clamp.

part

The part object for this launch clamp.

Attribute: Read-only, cannot be set Part All
release()

Releases the docking clamp. Has no effect if the clamp has already been released.

Game Scenes: All

Light¶

class Light

A light. Obtained by calling Part.light.

part

The part object for this light.

Attribute: Read-only, cannot be set Part All
active

Whether the light is switched on.

Attribute: Can be read or written bool All
color

The color of the light, as an RGB triple.

Attribute: Can be read or written tuple(float, float, float) All
power_usage

The current power usage, in units of charge per second.

Attribute: Read-only, cannot be set float All

Parachute¶

class Parachute

A parachute. Obtained by calling Part.parachute.

part

The part object for this parachute.

Attribute: Read-only, cannot be set Part All
deploy()

Deploys the parachute. This has no effect if the parachute has already been deployed.

Game Scenes: All
deployed

Whether the parachute has been deployed.

Attribute: Read-only, cannot be set bool All
arm()

Deploys the parachute. This has no effect if the parachute has already been armed or deployed. Only applicable to RealChutes parachutes.

Game Scenes: All
armed

Whether the parachute has been armed or deployed. Only applicable to RealChutes parachutes.

Attribute: Read-only, cannot be set bool All
state

The current state of the parachute.

Attribute: Read-only, cannot be set ParachuteState All
deploy_altitude

The altitude at which the parachute will full deploy, in meters. Only applicable to stock parachutes.

Attribute: Can be read or written float All
deploy_min_pressure

The minimum pressure at which the parachute will semi-deploy, in atmospheres. Only applicable to stock parachutes.

Attribute: Can be read or written float All
class ParachuteState

The state of a parachute. See Parachute.state.

stowed

The parachute is safely tucked away inside its housing.

armed

The parachute is armed for deployment. (RealChutes only)

active

The parachute is still stowed, but ready to semi-deploy. (Stock parachutes only)

semi_deployed

The parachute has been deployed and is providing some drag, but is not fully deployed yet. (Stock parachutes only)

deployed

The parachute is fully deployed.

cut

The parachute has been cut.

class Radiator

A radiator. Obtained by calling Part.radiator.

part

The part object for this radiator.

Attribute: Read-only, cannot be set Part All
deployable

Attribute: Read-only, cannot be set bool All
deployed

For a deployable radiator, True if the radiator is extended. If the radiator is not deployable, this is always True.

Attribute: Can be read or written bool All
state

The current state of the radiator.

Attribute: Read-only, cannot be set RadiatorState All

Note

A fixed radiator is always RadiatorState.extended.

class RadiatorState

The state of a radiator. RadiatorState

extended

retracted

extending

retracting

broken

Resource Converter¶

class ResourceConverter

A resource converter. Obtained by calling Part.resource_converter.

part

The part object for this converter.

Attribute: Read-only, cannot be set Part All
count

The number of converters in the part.

Attribute: Read-only, cannot be set int All
name(index)

The name of the specified converter.

Parameters: index (int) – Index of the converter. str All
active(index)

True if the specified converter is active.

Parameters: index (int) – Index of the converter. bool All
start(index)

Start the specified converter.

Parameters: index (int) – Index of the converter. All
stop(index)

Stop the specified converter.

Parameters: index (int) – Index of the converter. All
state(index)

The state of the specified converter.

Parameters: index (int) – Index of the converter. ResourceConverterState All
status_info(index)

Status information for the specified converter. This is the full status message shown in the in-game UI.

Parameters: index (int) – Index of the converter. str All
inputs(index)

List of the names of resources consumed by the specified converter.

Parameters: index (int) – Index of the converter. list(str) All
outputs(index)

List of the names of resources produced by the specified converter.

Parameters: index (int) – Index of the converter. list(str) All
optimum_core_temperature

The core temperature at which the converter will operate with peak efficiency, in Kelvin.

Attribute: Read-only, cannot be set float All
core_temperature

The core temperature of the converter, in Kelvin.

Attribute: Read-only, cannot be set float All
thermal_efficiency

The thermal efficiency of the converter, as a percentage of its maximum.

Attribute: Read-only, cannot be set float All
class ResourceConverterState

The state of a resource converter. See ResourceConverter.state().

running

Converter is running.

idle

Converter is idle.

missing_resource

Converter is missing a required resource.

storage_full

No available storage for output resource.

capacity

At preset resource capacity.

unknown

Unknown state. Possible with modified resource converters. In this case, check ResourceConverter.status_info() for more information.

Resource Harvester¶

class ResourceHarvester

A resource harvester (drill). Obtained by calling Part.resource_harvester.

part

The part object for this harvester.

Attribute: Read-only, cannot be set Part All
state

The state of the harvester.

Attribute: Read-only, cannot be set ResourceHarvesterState All
deployed

Whether the harvester is deployed.

Attribute: Can be read or written bool All
active

Whether the harvester is actively drilling.

Attribute: Can be read or written bool All
extraction_rate

The rate at which the drill is extracting ore, in units per second.

Attribute: Read-only, cannot be set float All
thermal_efficiency

The thermal efficiency of the drill, as a percentage of its maximum.

Attribute: Read-only, cannot be set float All
core_temperature

The core temperature of the drill, in Kelvin.

Attribute: Read-only, cannot be set float All
optimum_core_temperature

The core temperature at which the drill will operate with peak efficiency, in Kelvin.

Attribute: Read-only, cannot be set float All
class ResourceHarvesterState

The state of a resource harvester. See ResourceHarvester.state.

deploying

The drill is deploying.

deployed

The drill is deployed and ready.

retracting

The drill is retracting.

retracted

The drill is retracted.

active

The drill is running.

Reaction Wheel¶

class ReactionWheel

A reaction wheel. Obtained by calling Part.reaction_wheel.

part

The part object for this reaction wheel.

Attribute: Read-only, cannot be set Part All
active

Whether the reaction wheel is active.

Attribute: Can be read or written bool All
broken

Whether the reaction wheel is broken.

Attribute: Read-only, cannot be set bool All
available_torque

The available torque, in Newton meters, that can be produced by this reaction wheel, in the positive and negative pitch, roll and yaw axes of the vessel. These axes correspond to the coordinate axes of the Vessel.reference_frame. Returns zero if the reaction wheel is inactive or broken.

Attribute: Read-only, cannot be set tuple(tuple(double, double, double), tuple(double, double, double)) All
max_torque

The maximum torque, in Newton meters, that can be produced by this reaction wheel, when it is active, in the positive and negative pitch, roll and yaw axes of the vessel. These axes correspond to the coordinate axes of the Vessel.reference_frame.

Attribute: Read-only, cannot be set tuple(tuple(double, double, double), tuple(double, double, double)) All

RCS¶

class RCS

An RCS block or thruster. Obtained by calling Part.rcs.

part

The part object for this RCS.

Attribute: Read-only, cannot be set Part All
active

Whether the RCS thrusters are active. An RCS thruster is inactive if the RCS action group is disabled (Control.rcs), the RCS thruster itself is not enabled (RCS.enabled) or it is covered by a fairing (Part.shielded).

Attribute: Read-only, cannot be set bool All
enabled

Whether the RCS thrusters are enabled.

Attribute: Can be read or written bool All
pitch_enabled

Whether the RCS thruster will fire when pitch control input is given.

Attribute: Can be read or written bool All
yaw_enabled

Whether the RCS thruster will fire when yaw control input is given.

Attribute: Can be read or written bool All
roll_enabled

Whether the RCS thruster will fire when roll control input is given.

Attribute: Can be read or written bool All
forward_enabled

Whether the RCS thruster will fire when pitch control input is given.

Attribute: Can be read or written bool All
up_enabled

Whether the RCS thruster will fire when yaw control input is given.

Attribute: Can be read or written bool All
right_enabled

Whether the RCS thruster will fire when roll control input is given.

Attribute: Can be read or written bool All
available_torque

The available torque, in Newton meters, that can be produced by this RCS, in the positive and negative pitch, roll and yaw axes of the vessel. These axes correspond to the coordinate axes of the Vessel.reference_frame. Returns zero if RCS is disable.

Attribute: Read-only, cannot be set tuple(tuple(double, double, double), tuple(double, double, double)) All
max_thrust

The maximum amount of thrust that can be produced by the RCS thrusters when active, in Newtons.

Attribute: Read-only, cannot be set float All
max_vacuum_thrust

The maximum amount of thrust that can be produced by the RCS thrusters when active in a vacuum, in Newtons.

Attribute: Read-only, cannot be set float All
thrusters

A list of thrusters, one of each nozzel in the RCS part.

Attribute: Read-only, cannot be set list(Thruster) All
specific_impulse

The current specific impulse of the RCS, in seconds. Returns zero if the RCS is not active.

Attribute: Read-only, cannot be set float All
vacuum_specific_impulse

The vacuum specific impulse of the RCS, in seconds.

Attribute: Read-only, cannot be set float All
kerbin_sea_level_specific_impulse

The specific impulse of the RCS at sea level on Kerbin, in seconds.

Attribute: Read-only, cannot be set float All
propellants

The names of resources that the RCS consumes.

Attribute: Read-only, cannot be set list(str) All
propellant_ratios

The ratios of resources that the RCS consumes. A dictionary mapping resource names to the ratios at which they are consumed by the RCS.

Attribute: Read-only, cannot be set dict(str, float) All
has_fuel

Whether the RCS has fuel available.

Attribute: Read-only, cannot be set bool All

Note

The RCS thruster must be activated for this property to update correctly.

Sensor¶

class Sensor

A sensor, such as a thermometer. Obtained by calling Part.sensor.

part

The part object for this sensor.

Attribute: Read-only, cannot be set Part All
active

Whether the sensor is active.

Attribute: Can be read or written bool All
value

The current value of the sensor.

Attribute: Read-only, cannot be set str All

Solar Panel¶

class SolarPanel

A solar panel. Obtained by calling Part.solar_panel.

part

The part object for this solar panel.

Attribute: Read-only, cannot be set Part All
deployable

Whether the solar panel is deployable.

Attribute: Read-only, cannot be set bool All
deployed

Whether the solar panel is extended.

Attribute: Can be read or written bool All
state

The current state of the solar panel.

Attribute: Read-only, cannot be set SolarPanelState All
energy_flow

The current amount of energy being generated by the solar panel, in units of charge per second.

Attribute: Read-only, cannot be set float All
sun_exposure

The current amount of sunlight that is incident on the solar panel, as a percentage. A value between 0 and 1.

Attribute: Read-only, cannot be set float All
class SolarPanelState

The state of a solar panel. See SolarPanel.state.

extended

Solar panel is fully extended.

retracted

Solar panel is fully retracted.

extending

Solar panel is being extended.

retracting

Solar panel is being retracted.

broken

Solar panel is broken.

Thruster¶

class Thruster

The component of an Engine or RCS part that generates thrust. Can obtained by calling Engine.thrusters or RCS.thrusters.

Note

Engines can consist of multiple thrusters. For example, the S3 KS-25x4 “Mammoth” has four rocket nozzels, and so consists of four thrusters.

part

The Part that contains this thruster.

Attribute: Read-only, cannot be set Part All
thrust_position(reference_frame)

The position at which the thruster generates thrust, in the given reference frame. For gimballed engines, this takes into account the current rotation of the gimbal.

Parameters: reference_frame (ReferenceFrame) – The reference frame that the returned position vector is in. The position as a vector. tuple(double, double, double) All
thrust_direction(reference_frame)

The direction of the force generated by the thruster, in the given reference frame. This is opposite to the direction in which the thruster expels propellant. For gimballed engines, this takes into account the current rotation of the gimbal.

Parameters: reference_frame (ReferenceFrame) – The reference frame that the returned direction is in. The direction as a unit vector. tuple(double, double, double) All
thrust_reference_frame

A reference frame that is fixed relative to the thruster and orientated with its thrust direction (Thruster.thrust_direction()). For gimballed engines, this takes into account the current rotation of the gimbal.

• The origin is at the position of thrust for this thruster (Thruster.thrust_position()).
• The axes rotate with the thrust direction. This is the direction in which the thruster expels propellant, including any gimballing.
• The y-axis points along the thrust direction.
• The x-axis and z-axis are perpendicular to the thrust direction.
Attribute: Read-only, cannot be set ReferenceFrame All
gimballed

Whether the thruster is gimballed.

Attribute: Read-only, cannot be set bool All
gimbal_position(reference_frame)

Position around which the gimbal pivots.

Parameters: reference_frame (ReferenceFrame) – The reference frame that the returned position vector is in. The position as a vector. tuple(double, double, double) All
gimbal_angle

The current gimbal angle in the pitch, roll and yaw axes, in degrees.

Attribute: Read-only, cannot be set tuple(double, double, double) All
initial_thrust_position(reference_frame)

The position at which the thruster generates thrust, when the engine is in its initial position (no gimballing), in the given reference frame.

Parameters: reference_frame (ReferenceFrame) – The reference frame that the returned position vector is in. The position as a vector. tuple(double, double, double) All

Note

This position can move when the gimbal rotates. This is because the thrust position and gimbal position are not necessarily the same.

initial_thrust_direction(reference_frame)

The direction of the force generated by the thruster, when the engine is in its initial position (no gimballing), in the given reference frame. This is opposite to the direction in which the thruster expels propellant.

Parameters: reference_frame (ReferenceFrame) – The reference frame that the returned direction is in. The direction as a unit vector. tuple(double, double, double) All

Wheel¶

class Wheel

A wheel. Includes landing gear and rover wheels. Obtained by calling Part.wheel. Can be used to control the motors, steering and deployment of wheels, among other things.

part

The part object for this wheel.

Attribute: Read-only, cannot be set Part All
state

The current state of the wheel.

Attribute: Read-only, cannot be set WheelState All
radius

Radius of the wheel, in meters.

Attribute: Read-only, cannot be set float All
grounded

Whether the wheel is touching the ground.

Attribute: Read-only, cannot be set bool All
has_brakes

Whether the wheel has brakes.

Attribute: Read-only, cannot be set bool All
brakes

The braking force, as a percentage of maximum, when the brakes are applied.

Attribute: Can be read or written float All
auto_friction_control

Whether automatic friction control is enabled.

Attribute: Can be read or written bool All
manual_friction_control

Manual friction control value. Only has an effect if automatic friction control is disabled. A value between 0 and 5 inclusive.

Attribute: Can be read or written float All
deployable

Whether the wheel is deployable.

Attribute: Read-only, cannot be set bool All
deployed

Whether the wheel is deployed.

Attribute: Can be read or written bool All
powered

Attribute: Read-only, cannot be set bool All
motor_enabled

Whether the motor is enabled.

Attribute: Can be read or written bool All
motor_inverted

Whether the direction of the motor is inverted.

Attribute: Can be read or written bool All
motor_state

Whether the direction of the motor is inverted.

Attribute: Read-only, cannot be set MotorState All
motor_output

The output of the motor. This is the torque currently being generated, in Newton meters.

Attribute: Read-only, cannot be set float All
traction_control_enabled

Whether automatic traction control is enabled. A wheel only has traction control if it is powered.

Attribute: Can be read or written bool All
traction_control

Setting for the traction control. Only takes effect if the wheel has automatic traction control enabled. A value between 0 and 5 inclusive.

Attribute: Can be read or written float All
drive_limiter

Manual setting for the motor limiter. Only takes effect if the wheel has automatic traction control disabled. A value between 0 and 100 inclusive.

Attribute: Can be read or written float All
steerable

Whether the wheel has steering.

Attribute: Read-only, cannot be set bool All
steering_enabled

Whether the wheel steering is enabled.

Attribute: Can be read or written bool All
steering_inverted

Whether the wheel steering is inverted.

Attribute: Can be read or written bool All
has_suspension

Whether the wheel has suspension.

Attribute: Read-only, cannot be set bool All
suspension_spring_strength

Suspension spring strength, as set in the editor.

Attribute: Read-only, cannot be set float All
suspension_damper_strength

Suspension damper strength, as set in the editor.

Attribute: Read-only, cannot be set float All
broken

Whether the wheel is broken.

Attribute: Read-only, cannot be set bool All
repairable

Whether the wheel is repairable.

Attribute: Read-only, cannot be set bool All
stress

Current stress on the wheel.

Attribute: Read-only, cannot be set float All
stress_tolerance

Stress tolerance of the wheel.

Attribute: Read-only, cannot be set float All
stress_percentage

Current stress on the wheel as a percentage of its stress tolerance.

Attribute: Read-only, cannot be set float All
deflection

Current deflection of the wheel.

Attribute: Read-only, cannot be set float All
slip

Current slip of the wheel.

Attribute: Read-only, cannot be set float All
class WheelState

The state of a wheel. See Wheel.state.

deployed

Wheel is fully deployed.

retracted

Wheel is fully retracted.

deploying

Wheel is being deployed.

retracting

Wheel is being retracted.

broken

Wheel is broken.

class MotorState

The state of the motor on a powered wheel. See Wheel.motor_state.

idle

The motor is idle.

running

The motor is running.

disabled

The motor is disabled.

inoperable

The motor is inoperable.

not_enough_resources

The motor does not have enough resources to run.

Trees of Parts¶

Vessels in KSP are comprised of a number of parts, connected to one another in a tree structure. An example vessel is shown in Figure 1, and the corresponding tree of parts in Figure 2. The craft file for this example can also be downloaded here.

Figure 1 – Example parts making up a vessel.

Figure 2 – Tree of parts for the vessel in Figure 1. Arrows point from the parent part to the child part.

Traversing the Tree¶

The tree of parts can be traversed using the attributes Parts.root, Part.parent and Part.children.

The root of the tree is the same as the vessels root part (part number 1 in the example above) and can be obtained by calling Parts.root. A parts children can be obtained by calling Part.children. If the part does not have any children, Part.children returns an empty list. A parts parent can be obtained by calling Part.parent. If the part does not have a parent (as is the case for the root part), Part.parent returns None.

The following Python example uses these attributes to perform a depth-first traversal over all of the parts in a vessel:

import krpc
conn = krpc.connect()
vessel = conn.space_center.active_vessel

root = vessel.parts.root
stack = [(root, 0)]
while stack:
part, depth = stack.pop()
print(' '*depth, part.title)
for child in part.children:
stack.append((child, depth+1))


When this code is execute using the craft file for the example vessel pictured above, the following is printed out:

Command Pod Mk1
TR-18A Stack Decoupler
FL-T400 Fuel Tank
LV-909 Liquid Fuel Engine
TR-18A Stack Decoupler
FL-T800 Fuel Tank
LV-909 Liquid Fuel Engine
FL-T400 Fuel Tank
TT18-A Launch Stability Enhancer
FTX-2 External Fuel Duct
LV-909 Liquid Fuel Engine
Aerodynamic Nose Cone
FL-T400 Fuel Tank
TT18-A Launch Stability Enhancer
FTX-2 External Fuel Duct
LV-909 Liquid Fuel Engine
Aerodynamic Nose Cone
LT-1 Landing Struts
LT-1 Landing Struts
Mk16 Parachute


Attachment Modes¶

Parts can be attached to other parts either radially (on the side of the parent part) or axially (on the end of the parent part, to form a stack).

For example, in the vessel pictured above, the parachute (part 2) is axially connected to its parent (the command pod – part 1), and the landing leg (part 5) is radially connected to its parent (the fuel tank – part 4).

The root part of a vessel (for example the command pod – part 1) does not have a parent part, so does not have an attachment mode. However, the part is consider to be axially attached to nothing.

The following Python example does a depth-first traversal as before, but also prints out the attachment mode used by the part:

import krpc
conn = krpc.connect()
vessel = conn.space_center.active_vessel

root = vessel.parts.root
stack = [(root, 0)]
while stack:
part, depth = stack.pop()
if part.axially_attached:
attach_mode = 'axial'
print(' '*depth, part.title, '-', attach_mode)
for child in part.children:
stack.append((child, depth+1))


When this code is execute using the craft file for the example vessel pictured above, the following is printed out:

Command Pod Mk1 - axial
TR-18A Stack Decoupler - axial
FL-T400 Fuel Tank - axial
LV-909 Liquid Fuel Engine - axial
TR-18A Stack Decoupler - axial
FL-T800 Fuel Tank - axial
LV-909 Liquid Fuel Engine - axial
TT18-A Launch Stability Enhancer - radial
FTX-2 External Fuel Duct - radial
LV-909 Liquid Fuel Engine - axial
Aerodynamic Nose Cone - axial
TT18-A Launch Stability Enhancer - radial
FTX-2 External Fuel Duct - radial
LV-909 Liquid Fuel Engine - axial
Aerodynamic Nose Cone - axial
Mk16 Parachute - axial


Fuel Lines¶

Figure 5 – Fuel lines from the example in Figure 1. Fuel flows from the parts highlighted in green, into the part highlighted in blue.

Figure 4 – A subset of the parts tree from Figure 2 above.

Fuel lines are considered parts, and are included in the parts tree (for example, as pictured in Figure 4). However, the parts tree does not contain information about which parts fuel lines connect to. The parent part of a fuel line is the part from which it will take fuel (as shown in Figure 4) however the part that it will send fuel to is not represented in the parts tree.

Figure 5 shows the fuel lines from the example vessel pictured earlier. Fuel line part 15 (in red) takes fuel from a fuel tank (part 11 – in green) and feeds it into another fuel tank (part 9 – in blue). The fuel line is therefore a child of part 11, but its connection to part 9 is not represented in the tree.

The attributes Part.fuel_lines_from and Part.fuel_lines_to can be used to discover these connections. In the example in Figure 5, when Part.fuel_lines_to is called on fuel tank part 11, it will return a list of parts containing just fuel tank part 9 (the blue part). When Part.fuel_lines_from is called on fuel tank part 9, it will return a list containing fuel tank parts 11 and 17 (the parts colored green).

Staging¶

Figure 6 – Example vessel from Figure 1 with a staging sequence.

Each part has two staging numbers associated with it: the stage in which the part is activated and the stage in which the part is decoupled. These values can be obtained using Part.stage and Part.decouple_stage respectively. For parts that are not activated by staging, Part.stage returns -1. For parts that are never decoupled, Part.decouple_stage returns a value of -1.

Figure 6 shows an example staging sequence for a vessel. Figure 7 shows the stages in which each part of the vessel will be activated. Figure 8 shows the stages in which each part of the vessel will be decoupled.

Figure 7 – The stage in which each part is activated.

Figure 8 – The stage in which each part is decoupled.