Name

Description

Attributes

Ap

The dimensionless planetary index (Ap) used by the JacchiaRoberts and MSIS atmospheric density models at the Spacecraft's current epoch. This property is only valid when the AtmosphericDensityModel property is set to a JacchiaRoberts or MSIS density model.

Type: Variable
Access: ReadOnly

AtmosphericDensityModel

Determines the type of Atmospheric Density Model to be used when Drag or Lift forces are selected.

Type: Variable
Access: Read/Write

CelestialObjects

The array of gravitational bodies in the force model.

Type: Array of CelestialObject
Access: ReadOnly

DeclaredName

The name of the object as declared.

Type: String
Access: ReadOnly

DisplayName

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

Type: String
Access: Read/Write

Drag

Determines whether Atmospheric Drag force modeling is used during propagation.

Type: Variable
Access: Read/Write

Earth

Specifies whether gravitational forces from the Earth will be used to calculate applied accelerations during propagation. The planetary ephemeris file is used as an input source. The ForceModel.PlanetFieldType array is used to determine whether gravitational effects are modeled as a point mass or a nonspherical gravitational field.

Type: Variable
Access: Read/Write

F107Index

The F10.7 index value that is used by the JacchiaRoberts and MSIS atmospheric density models to calculate the exospheric temperature at the Spacecraft's current epoch. These models use the F10.7 index value from 1 day previous to the Spacecraft's current epoch in calculating exospheric temperature, due to the time it takes for solar fluctuations to affect Earth's atmosphere. Therefore, the value reported by this property corresponds to the F10.7 index value 1 day previous to the Spacecraft's current epoch. Solar flux units (sfu) are 1x1022 W/m^2/Hz. Note that you can not report F10.7 with files containing Tc/Kp data.

Type: Variable
Access: ReadOnly
Units: sfu

F107IndexAverage

The 81 day average F10.7 index value used by the JacchiaRoberts and MSIS atmospheric density models to calculate exospheric temperature. Solar flux units (sfu) are 1x1022 W/m^2/Hz.

Type: Variable
Access: ReadOnly
Units: sfu

HarrisPriesterDensityFilename

Specifies the HarrisPriester density model data file's path and name to be used when the DragType is set to HarrisPriester atmospheric density modeling. If no file is specified ("DEFAULT"), then the file specified in Project Preferences for HarrisPriester Atmosphere Model File will be used.

Type: String
Access: Read/Write

HarrisPriesterF107Index

Specifies the F10.7 cm Solar Flux level that is to be used when DragType is set to HarrisPriester atmospheric density modeling. Solar flux units are 1x1022 W/m^2/Hz.

Type: Variable
Access: Read/Write

Jupiter

Specifies whether gravitational forces from Jupiter will be used to calculate applied accelerations during propagation. The planetary ephemeris file is used as an input source. The ForceModel.PlanetFieldType array is used to determine whether gravitational effects are modeled as a point mass or a nonspherical gravitational field.

Type: Variable
Access: Read/Write

Kp

The dimensionless geomagnetic index (Kp) used by the JacchiaRoberts and MSIS atmospheric density models at the Spacecraft's current epoch. These indices are stored in the JacchiaRoberts file in threehour increments. This property is only valid when the AtmosphericDensityModel property is set to a JacchiaRoberts or MSIS density model.

Type: Variable
Access: ReadOnly

Lift

Determines whether Atmospheric Lift force modeling is used during propagation.

Type: Variable
Access: Read/Write

Mars

Specifies whether gravitational forces from Mars will be used to calculate applied accelerations during propagation. The planetary ephemeris file is used as an input source. The ForceModel.PlanetFieldType array is used to determine whether gravitational effects are modeled as a point mass or a nonspherical gravitational field.

Type: Variable
Access: Read/Write

Mercury

Specifies whether gravitational forces from Mercury will be used to calculate applied accelerations during propagation. The planetary ephemeris file is used as an input source. The ForceModel.PlanetFieldType array is used to determine whether gravitational effects are modeled as a point mass or a nonspherical gravitational field.

Type: Variable
Access: Read/Write

Moon

Specifies whether gravitational forces from the Moon will be used to calculate applied accelerations during propagation. The planetary ephemeris file is used as an input source. The ForceModel.PlanetFieldType array is used to determine whether gravitational effects are modeled as a point mass or a nonspherical gravitational field.

Type: Variable
Access: Read/Write

Neptune

Specifies whether gravitational forces from Neptune will be used to calculate applied accelerations during propagation. The planetary ephemeris file is used as an input source. The ForceModel.PlanetFieldType array is used to determine whether gravitational effects are modeled as a point mass or a nonspherical gravitational field.

Type: Variable
Access: Read/Write

ObjectId

The unique identifier for the object.

Type: Variable
Access: ReadOnly

ObjectType

The type of the object.

Type: String
Access: ReadOnly

OtherAccelerations

The unmodeled acceleration vector.

Type: Array
Access: Read/Write
Units: km/s^2

OtherAccelerationsRate

The rate of change of the unmodeled acceleration vector.

Type: Array
Access: Read/Write
Units: km/s^3

PlanetFieldDegree

Specifies the number of Zonal harmonic terms that are to be used when modeling a nonspherical, nonhomogenous gravity field.

Type: Array
Access: Read/Write

PlanetFieldOrder

Specifies the number of Tesseral harmonic terms that are to be used when modeling a nonspherical, nonhomogenous gravity field. The FieldOrder must be a value no greater than that specified by the FieldDegree.

Type: Array
Access: Read/Write

PlanetFieldType

Specifies the FieldTypes to be used in modeling the Bodies' gravitational potentials.
Value Potential Field Type
0 = Point Mass Gravity
1 = Zonal Potential Terms Only
2 = Zonal and Tesseral Terms
3 = Zonal and Tesseral Terms with Solid Tides.

Type: Array
Access: Read/Write

PlanetoPotentialFilename

Specifies the planetopotential data files' paths and names for modeling nonspherical, nonhomogenous gravity fields. If no file is specified for Earth ("DEFAULT"), then the file specified in Project Preferences for Geopotential File will be used.
The potential file used for each celestial body contains values for the physical properties of the body (Gravity Constant (mu), Body Radius, Reciprocal Flattening). These values are used when propagating the Spacecraft any time a potential file is used. For other calculations that depend on the physical properties of a celestial body, such as Spacecraft.Height or propagation of a Spacecraft with a point mass gravitational model, the celestial body physical properties are set using syntax such as "Earth.Mu".

Type: StringArray
Access: Read/Write

Pluto

Specifies whether gravitational forces from Pluto will be used to calculate applied accelerations during propagation. The DEplanetary ephemeris file is used as an input source. The ForceModel.PlanetFieldType array is used to determine whether gravitational effects are modeled as a point mass or a nonspherical gravitational field.

Type: Variable
Access: Read/Write

Rho1

The density scale factor. FreeFlyer computes an effective atmospheric density based on the following equation: Rho = Rho0(1 + Rho1), where Rho is the effective density, Rho0 is the nominal density, and Rho1 is the density scale factor.

Type: Variable
Access: Read/Write

Saturn

Specifies whether gravitational forces from Saturn will be used to calculate applied accelerations during propagation. The planetary ephemeris file is used as an input source. The ForceModel.PlanetFieldType array is used to determine whether gravitational effects are modeled as a point mass or a nonspherical gravitational field.

Type: Variable
Access: Read/Write

Sigma_Rho1

The uncertainty of the density scale factor. Note: This property is used by the OrbitDetermination object.

Type: Variable
Access: Read/Write

Sigma_Ux

The uncertainty of the unmodeled acceleration in the Xdirection. Note: This property is used by the OrbitDetermination object.

Type: Variable
Access: Read/Write
Units: km/s^2

Sigma_Uy

The uncertainty of the unmodeled acceleration in the Ydirection. Note: This property is used by the OrbitDetermination object.

Type: Variable
Access: Read/Write
Units: km/s^2

Sigma_Uz

The uncertainty of the unmodeled acceleration in the Zdirection. Note: This property is used by the OrbitDetermination object.

Type: Variable
Access: Read/Write
Units: km/s^2

SolarFluxFilename

Specifies the Solar Flux Predict data file's path and name to be used when the DragType is set to JacchiaRoberts or MSIS atmospheric density modeling. If no file is specified ("DEFAULT"), then the file specified in Project Preferences for the Solar Flux Predict file will be used.

Type: String
Access: Read/Write

SolidTideDegree

Specifies the number of Zonal harmonic terms that are to be used when modeling Solid Tides for the Central Body.

Type: Array
Access: Read/Write

SolidTideFilename

Specifies the Solid Tide Love Number data files' paths and names for modeling the solid tide effects on the gravity field. If no file is specified ("DEFAULT"), then the file specified in Project Preferences for Love Number File will be used.

Type: StringArray
Access: Read/Write

SolidTideOrder

Specifies the number of Tesseral harmonic terms that are to be used when modeling Solid Tides for the Central Body.

Type: Array
Access: Read/Write

SRP

Determines whether Solar Radiation Pressure (SRP) force modeling is used during propagation.

Type: Variable
Access: Read/Write

SRPForceGeometry

Determines the SRP calculation mode to use. A value of 0 corresponds to a spherical model. A value of 1 corresponds to an analytic plate model. The plate model must be configured through the Spacecraft.PlateModel settings. Note that this model does not include selfshadowing.

Type: Variable
Access: Read/Write

Sun

Specifies whether gravitational forces from the Sun will be used to calculate applied accelerations during propagation. The planetary ephemeris file is used as an input source. The ForceModel.PlanetFieldType array is used to determine whether gravitational effects are modeled as a point mass or a nonspherical gravitational field.

Type: Variable
Access: Read/Write

Tc

Represents the current value of the exospheric temperature used by the JacchiaRoberts and MSIS atmospheric density models to calculate atmospheric density at the Spacecraft's current epoch.

Type: Variable
Access: ReadOnly
Units: Deg K

Uranus

Specifies whether gravitational forces from Uranus will be used to calculate applied accelerations during propagation. The planetary ephemeris file is used as an input source. The ForceModel.PlanetFieldType array is used to determine whether gravitational effects are modeled as a point mass or a nonspherical gravitational field.

Type: Variable
Access: Read/Write

UseBodyForce

Flag array indicating whether to use each gravitational body. The UseBodyForce array flags the gravitational bodies in the order of the Planets, the Moon, and then the Sun. If there are custom CelestialObjects also included they will increase the size of your array in and by the order of the added CelestialObjects.

Type: Array
Access: Read/Write

UseOtherAcceleration

Determines whether the specified unmodeled accelerations are used during propagation.

Type: Variable
Access: Read/Write

UseZeroTideModel

Flag array indicating whether each body's gravitational field includes the permanent tide effects (ZeroTide).

Type: Array
Access: Read/Write

Venus

Specifies whether gravitational forces from Venus will be used to calculate applied accelerations during propagation. The planetary ephemeris file is used as an input source. The ForceModel.PlanetFieldType array is used to determine whether gravitational effects are modeled as a point mass or a nonspherical gravitational field.

Type: Variable
Access: Read/Write
