In an Initial State, Follow, or Launch segment, you can use these attributes to define the Spacecraft and Fuel Tank physical properties that are used by the segment in the Mission Control Sequence (MCS).
Astrogator <Satellite Object Path> SetValue <Astrogator Object Path>.{PhysicalProperty} <Value> <Unit>
The following abbreviations are used:
All of the other properties are named the same in Connect as they are in the Astrogator user interface but without spaces between words.
The Spacecraft Parameters are defined in the following table:
| Field | Description |
|---|---|
| Dry Mass | The mass of the spacecraft exclusive of propellant. Enter a value in the selected mass unit (e.g., kg). |
| Drag Area | The cross-sectional area of the spacecraft assumed perpendicular to the direction of motion, used for atmospheric drag calculations. Enter a value in the selected distance unit squared. |
| Drag Coefficient (Cd) | The dimensionless drag coefficient associated with the drag area. |
| Solar Radiation Pressure (Spherical) Area | The cross-sectional area of the spacecraft assumed perpendicular to the direction of solar radiation, used for solar radiation calculations. Enter a value in the selected distance unit squared. |
| Solar Radiation Pressure (Spherical) Coefficient (Cr) | The reflectivity of the spacecraft used for solar radiation pressure calculations, where 2.0 is fully reflective and 1.0 is not reflective at all. |
| Radiation Pressure (Albedo/Thermal) Area | The cross-sectional area of the spacecraft assumed perpendicular to the direction of central body radiation, used for central body radiation (albedo / thermal pressure) calculations. Enter a value in the selected distance unit squared. |
| Radiation Pressure (Albedo/Thermal) Coefficient (Ck) | The reflectivity of the spacecraft used for central body radiation pressure (albedo / thermal pressure) calculations, where 2.0 is fully reflective and 1.0 is not reflective at all. |
| GPS Solar Radiation Pressure K1 | If you are using a non-spherical SRP model, this field defines the model's K1 (scale) value. |
| GPS Solar Radiation Pressure K2 | If you are using a non-spherical SRP model, this field defines the model's K2 (Y bias) value. |
The Fuel Tank Parameters are defined in the following table:
| Field | Description |
|---|---|
| Tank Pressure | The fuel tank pressure. Enter a value in the selected pressure unit (e.g., Pa). |
| Tank Temperature | The temperature of the fuel tank. Enter a value in the selected temperature unit. |
| Fuel Density | The density of the fuel. Enter a value in the selected mass unit per the selected distance unit cubed (e.g., kg/m^3). |
| Fuel Mass | The mass of the spacecraft propellant. Enter a value in the selected mass unit (e.g., kg). |
Note: The Tank Volume and Maximum Fuel Mass parameters are related to the actual satellite object, and are not state values. Therefore, they do not appear in this Fuel Tank Parameters table; they remain set to their default values and can only be modified within the MCS. See MaxFuelMass and TankVolume.
Astrogator */Satellite/Satellite1 SetValue MainSequence.SegmentList.Initial_State.InitialState.TankTemperature 300 K
Astrogator */Satellite/Satellite1 SetValue MainSequence.SegmentList.Launch.InitialState.TankTemperature 300 K
Astrogator */Satellite/Satellite1 SetValue MainSequence.SegmentList.Follow.InitialState.FuelMass 200 kg
STK Programming Interface 11.0.1