Thruster Object

Signatures

Description

Thruster()

Create a Thruster.

Thruster(Tank fuelTank)

Create a Thruster with a specified FuelTank.

Name

Description

Attributes

AveragePreInletPress

Average Tank pressure prior to Thruster inlet. This is a weighted average (based on mix ratio) of the Tank.TankPressure property of all attached Tanks with open valves. This property is used in the calculation of the Thruster.ThrusterInletPressure along with the Thruster pressure drop coefficients.

Type:   Variable

Access: Read-Only

Units:   kPa

AveragePreInletRefTemp

Average Tank reference temperature prior to Thruster inlet. This is a weighted average (based on mix ratio) of the Tank.TankRefTemperature property of all attached Tanks with open valves. This property is used in the calculation of Thrust and Isp along with the AveragePreInletTemp, ThrusterInletPressure, and Thruster coefficients.

Type:   Variable

Access: Read-Only

Units:   Deg C

AveragePreInletTemp

Average Tank temperature prior to Thruster inlet. This is a weighted average (based on mix ratio) of the Tank.TankTemperature property of all attached Tanks with open valves. This property is used in the calculation of Thrust and Isp along with the AveragePreInletRefTemp, ThrusterInletPressure, and Thruster coefficients.

Type:   Variable

Access: Read-Only

Units:   Deg C

DeclaredName

The name of the object as declared.

Type:   String

Access: Read-Only

DutyCycle

The percentage of on-time of the thruster during a burn. This property scales the mass depletion and the acceleration due to thrust.

Type:   Variable

Access: Read/Write

ForceTankConsistency

Determines whether the temperature and/or pressure of the attached Tanks are equalized post-burn. The equalized temperature and/or pressure are computed as a weighted average of all attached Tanks, based on their mix ratios.

Type:   Variable

Access: Read/Write

IspScaleFactor

Scale factor applied to the Isp that is used in determining mass flow.

Type:   Variable

Access: Read/Write

MaxPressureDiff

The maximum pressure difference that is allowed between Tanks attached to this Thruster, if consistency checking is enabled by setting TestTankConsistency to 1.

Type:   Variable

Access: Read/Write

Units:   kPa

MaxTempDiff

Maximum temperature difference that is allowed between Tanks attached to this Thruster, if consistency checking is enabled by setting TestTankConsistency to 1.

Type:   Variable

Access: Read/Write

Units:   Deg C

Name

The name displayed for this object in output windows such as views, plots, and reports.

Type:   String

Access: Read/Write

ObjectId

The unique identifier for the object.

Type:   Variable

Access: Read-Only

ObjectType

The type of the object.

Type:   String

Access: Read-Only

Orientation

Dimensionless unit vector representing pointing direction of the applied acceleration in the Spacecraft body coordinate frame. This is only used to determine the direction of applied acceleration when a Finite Burn using the "Attitude" system is used to maneuver the Spacecraft. Otherwise, the FiniteBurn or ImpulsiveBurn object specifies the direction of the maneuver.

Type:   Array

Access: Read/Write

Units:   m

Position

The vector representing the dry vehicle center of mass (i.e. no attached Tanks are included in this property) referenced from the origin of the Spacecraft's body fixed frame. This property is used in calculating the CenterOfMass, which includes all attached Tanks in its calculation.

Type:   Array

Access: Read/Write

Units:   m

ScaleFactor

A measure of the efficiency of the thruster. This property adjusts the acceleration due to thrust without changing the mass depletion.

Type:   Variable

Access: Read/Write

TankValve

Determines the state of a valve controlling mass flow from a set of tanks to the thruster. A value of 0 indicates no mass will flow and a value of 1 indicates mass will flow.

Type:   Array

Access: Read/Write

TestTankConsistency

Determines whether temperature and pressure consistency checks are performed when multiple Tanks simultaneously feed a Thruster.

Type:   Variable

Access: Read/Write

ThrusterC1

First coefficient of the thrust performance polynomial.

Type:   Variable

Access: Read/Write

Units:   N

ThrusterC10

Tenth coefficient of the thrust performance polynomial.

Type:   Variable

Access: Read/Write

Units:   N/kPa^C11

ThrusterC11

Eleventh coefficient of the thrust performance polynomial.

Type:   Variable

Access: Read/Write

ThrusterC12

Twelfth coefficient of the thrust performance polynomial.

Type:   Variable

Access: Read/Write

Units:   N

ThrusterC13

Thirteenth coefficient of the thrust performance polynomial.

Type:   Variable

Access: Read/Write

ThrusterC14

Fourteenth coefficient of the thrust performance polynomial.

Type:   Variable

Access: Read/Write

Units:   1/kPa

ThrusterC15

Fifteenth coefficient of the thrust performance polynomial.

Type:   Variable

Access: Read/Write

ThrusterC16

Sixteenth coefficient of the thrust performance polynomial.

Type:   Variable

Access: Read/Write

Units:   1/kPa

ThrusterC2

Second coefficient of the thrust performance polynomial.

Type:   Variable

Access: Read/Write

Units:   N/kPa

ThrusterC3

Third coefficient of the thrust performance polynomial.

Type:   Variable

Access: Read/Write

Units:   N

ThrusterC4

Fourth coefficient of the thrust performance polynomial.

Type:   Variable

Access: Read/Write

Units:   N/kPa

ThrusterC5

Fifth coefficient of the thrust performance polynomial.

Type:   Variable

Access: Read/Write

Units:   N/kPa^2

ThrusterC6

Sixth coefficient of the thrust performance polynomial.

Type:   Variable

Access: Read/Write

Units:   N/kPa^C7

ThrusterC7

Seventh coefficient of the thrust performance polynomial.

Type:   Variable

Access: Read/Write

ThrusterC8

Eighth coefficient of the thrust performance polynomial.

Type:   Variable

Access: Read/Write

Units:   N/kPa^C9

ThrusterC9

Ninth coefficient of the thrust performance polynomial.

Type:   Variable

Access: Read/Write

ThrusterGravityConst

The value of the gravitational acceleration at the surface of the Earth. Used in the conversion of specific impulse (Isp) between English and MKS units. The default value is 9.81 m/s^2 but can be adjusted to the value adopted by the thruster manufacturer. Used for mass depletion.

Type:   Variable

Access: Read/Write

Units:   m/s^2

ThrusterInletPressure

Pressure at the Thruster inlet. This is calculated based on the Thruster.AveragePreInletPressure property and the pressure drop coefficients, Thruster.PC1-6. This property is used in the calculation of Thrust and Isp along with the AveragePreInletTemp, AveragePreInletRefTemp, and Thruster coefficients.

Type:   Variable

Access: Read-Only

ThrusterK1

First coefficient of the specific impulse (Isp) performance polynomial.

Type:   Variable

Access: Read/Write

Units:   s

ThrusterK10

Tenth coefficient of the specific impulse (Isp) performance polynomial.

Type:   Variable

Access: Read/Write

Units:   s/kPa^K11

ThrusterK11

Eleventh coefficient of the specific impulse (Isp) performance polynomial.

Type:   Variable

Access: Read/Write

ThrusterK12

Twelfth coefficient of the specific impulse (Isp) performance polynomial.

Type:   Variable

Access: Read/Write

Units:   s

ThrusterK13

Thirteenth coefficient of the specific impulse (Isp) performance polynomial.

Type:   Variable

Access: Read/Write

ThrusterK14

Fourteenth coefficient of the specific impulse (Isp) performance polynomial.

Type:   Variable

Access: Read/Write

Units:   1/kPa

ThrusterK15

Fifteenth coefficient of the specific impulse (Isp) performance polynomial.

Type:   Variable

Access: Read/Write

ThrusterK16

Sixteenth coefficient of the specific impulse (Isp) performance polynomial.

Type:   Variable

Access: Read/Write

Units:   1/kPa

ThrusterK2

Second coefficient of the specific impulse (Isp) performance polynomial.

Type:   Variable

Access: Read/Write

Units:   s/kPa

ThrusterK3

Third coefficient of the specific impulse (Isp) performance polynomial.

Type:   Variable

Access: Read/Write

Units:   s

ThrusterK4

Fourth coefficient of the specific impulse (Isp) performance polynomial.

Type:   Variable

Access: Read/Write

Units:   s/kPa

ThrusterK5

Fifth coefficient of the specific impulse (Isp) performance polynomial.

Type:   Variable

Access: Read/Write

Units:   s/kPa^2

ThrusterK6

Sixth coefficient of the specific impulse (Isp) performance polynomial.

Type:   Variable

Access: Read/Write

Units:   s/kPa^K7

ThrusterK7

Seventh coefficient of the specific impulse (Isp) performance polynomial.

Type:   Variable

Access: Read/Write

ThrusterK8

Eighth coefficient of the specific impulse (Isp) performance polynomial.

Type:   Variable

Access: Read/Write

Units:   s/kPa^K9

ThrusterK9

Ninth coefficient of the specific impulse (Isp) performance polynomial.

Type:   Variable

Access: Read/Write

ThrusterOn

Determines whether a thruster is on or off. Individual valves connected to a Thruster can also be opened or closed using the Valve.State property.

Type:   Variable

Access: Read/Write

ThrusterPC1

First coefficient of the polynomial to model the pressure drop from Tank to Thruster

Type:   Variable

Access: Read/Write

Units:   kPa

ThrusterPC2

Second coefficient of the polynomial to model the pressure drop from Tank to Thruster

Type:   Variable

Access: Read/Write

ThrusterPC3

Third coefficient of the polynomial to model the pressure drop from Tank to Thruster

Type:   Variable

Access: Read/Write

ThrusterPC4

Fourth coefficient of the polynomial to model the pressure drop from Tank to Thruster

Type:   Variable

Access: Read/Write

ThrusterPC5

Fifth coefficient of the polynomial to model the pressure drop from Tank to Thruster

Type:   Variable

Access: Read/Write

ThrusterPC6

Sixth coefficient of the polynomial to model the pressure drop from Tank to Thruster

Type:   Variable

Access: Read/Write

Type

The type of thruster.

Type:   String

Access: Read/Write

UnboundedDutyCycle

The percentage of on-time of the thruster during a burn. This property offers the same functionality as the DutyCycle property, but doesn't have range restrictions. It is recomended that the primary DutyCycle property be used, but this property is supported to offer compatibility with previous versions of FreeFlyer. This property scales the mass depletion and the acceleration due to thrust.

Type:   Variable

Access: Read/Write

Valves

The Valves that connect the thruster to tanks.

Type:   Array of Valve

Access: Read-Only

Name

Description

AddTankToValve

Adds Tanks to an existing Valve of the Thruster.

ClearSavedStates

Clears previous saved states for this object.

GetFromFile

Load the object state from the specified FreeFlyer object file.

GetFromString

Load the object state from the specified string.

GetIsp

Returns the effective specific impulse (Isp) based on the propulsion model Isp polynomial evaluation, scaled by the IspScaleFactor. The Isp polynomial coefficients are specified by the Thruster.ThrusterK1-ThrusterK16 properties.

GetThrust

Returns the effective thrust based on the propulsion model thrust polynomial evaluation. The thrust polynomial coefficients are specified by the Thruster.ThrusterC1-ThrusterC16 properties. The Thruster Scale Factor and Duty Cycle are included in the calculation.

PutToFile

Convert the object state to FreeFlyer object xml and write to a file.

PutToString

Convert the object state to FreeFlyer object xml and return as a string.

ReferenceEquals

Returns 1 if the argument refers to the calling object and 0 otherwise.

Restore

Restore an object's state from a previously saved state.

Save

Save the object's state so that it can be restored later.

Name

Description

Attributes

ThrusterOrientX

X-component of the direction of the applied acceleration in the Spacecraft body coordinate frame. The pointing direction is always treated internally as a dimensionless unit-vector. This is only used to determine the direction of applied acceleration when a Finite Burn using the "Attitude" system is used to maneuver the Spacecraft. Otherwise, the FiniteBurn or ImpulsiveBurn object specifies the direction of the maneuver.

This property has been Deprecated. Please use Orientation instead.

Type:   Variable

Access: Read/Write

Units:   m

ThrusterOrientY

Y-component of the direction of the applied acceleration in the Spacecraft body coordinate frame. The pointing direction is always treated internally as a dimensionless unit-vector. This is only used to determine the direction of applied acceleration when a Finite Burn using the "Attitude" system is used to maneuver the Spacecraft. Otherwise, the FiniteBurn or ImpulsiveBurn object specifies the direction of the maneuver.

This property has been Deprecated. Please use Orientation instead.

Type:   Variable

Access: Read/Write

Units:   m

ThrusterOrientZ

Z-component of the direction of the applied acceleration in the Spacecraft body coordinate frame. The pointing direction is always treated internally as a dimensionless unit-vector. This is only used to determine the direction of applied acceleration when a Finite Burn using the "Attitude" system is used to maneuver the Spacecraft. Otherwise, the FiniteBurn or ImpulsiveBurn object specifies the direction of the maneuver.

This property has been Deprecated. Please use Orientation instead.

Type:   Variable

Access: Read/Write

Units:   m

ThrusterRefX

X component of the position of the Thruster in the Spacecraft body coordinate frame.

This property has been Deprecated. Please use Position instead.

Type:   Variable

Access: Read/Write

Units:   m

ThrusterRefY

Y component of the position of the Thruster in the Spacecraft body coordinate frame.

This property has been Deprecated. Please use Position instead.

Type:   Variable

Access: Read/Write

Units:   m

ThrusterRefZ

Z component of the position of the Thruster in the Spacecraft body coordinate frame.

This property has been Deprecated. Please use Position instead.

Type:   Variable

Access: Read/Write

Units:   m