Power Source Components

Internal Power | Processed Power | Solar Array

Astrogator makes the following power sources available for use in configuring engine models:

Power Source Description
Internal Power Power generated internally.
Processed Power Power available from a power processing unit (PPU).
Solar Array Power Power generated by a solar array.

Internal Power Source

For an internal power source, set the following parameters:

Internal Power Source User-Definable Attributes

Attribute Description
GeneratedPower Power generated by the spacecraft from internal sources.
PercentDegradationPerYear Degradation factor is (1 - x%/yr)timeSinceRefEpoch
ReferenceEpoch Date and time used as a reference epoch for degradation.

Processed Power Source

For a processed power source, set the following parameters:

Processed Power Source User-Definable Attributes

Attribute Description
Efficiency Efficiency of the PPU unit.
InputPowerSource Source of power available to the PPU.
Load Power diverted from the power source and unavailable to the PPU.

Solar Array Power Source

The Solar Array Power Source calculates one parameter, Power:

Where Fth is the Thermal Model Factor described below, D is the degradation factor described below (measured from the reference epoch), CE% is CellEfficiencyPct, AE% is ArrayEfficiencyPct, and ISL is the angle InclinationToSunLine. Flux is defined as:

where Fau is the solar flux at 1 au (from the central body file), and Rs is the apparent distance to the sun.

Solar Array Power Source User-Definable Attributes

Attribute Description
Area Solar array panel area.
Concentration Solar array concentration factor.
CellEfficiencyPct Cell efficiency in producing output power from incident sunlight.
ArrayEfficiencyPct Array efficiency in producing output power from a collection of cells.
PercentDegradationPerYear The degradation factor is (1 - x)n, where n is the time since epoch in years, and x is the percent degradation per year.
ReferenceEpoch Date and time used as a reference epoch for degradation.
InclinationToSunLine Angle from the panel normal vector to the apparent sun line.

Thermal Model Attributes

The Thermal factor can be calculated as a function of the distance (in AU) to the Sun:

where r is the magnitude of the radius vector in AU.

Thermal Model Coefficients

Coefficient Description
ThermalModel.C0 C0 coefficient.
ThermalModel.C1 C1 coefficient.
ThermalModel.C2 C2 coefficient.
ThermalModel.C3 C3 coefficient.
ThermalModel.C4 C4 coefficient.