Description
The SRP Area is the incident cross sectional area to the Sun-Earth line. It is used in the calculation of the force on the spacecraft due to solar radiation pressure.
If the Spacecraft's ForceModel.SRPForceGeometry is set to use a PlateModel, then this property will reflect the incident SRP area of the PlateModel, and an error will be reported if you try to assign a value to this property.
The formula used to calculate the acceleration due to solar radiation pressure is:
|
(1) |
Where:
•aSRP ≡ Acceleration due to solar radiation pressure •S ≡ Mean solar flux at one astronomical unit (AU), defined as 1,358.0 W/m2(1) •AU ≡ Astronomical Unit (the distance from the Earth to the Sun), defined as 149,597,870.0 km •CR ≡ Coefficient of Reflectivity of the Spacecraft •ASRP ≡ SRP Area (the cross-sectional area incident to the Sun-Earth line) •m ≡ Mass of the Spacecraft •R ≡ Distance from the Spacecraft to the Sun •c ≡ Speed of light, defined as 299,792.458 km/s •U ≡ Unit vector from the Spacecraft to the Sun •ν ≡ Eclipse factor, where: oν = 0 if the Spacecraft is in shadow (umbra) oν = 1 if the Spacecraft is in sunlight o0 < ν < 1 if the Spacecraft is in penumbra(2) |
(1) Larson, W. J. and Wertz, J. R. Space Mission Analysis and Design (2nd Ed.), Microcosm Press, El Segundo, CA
(2) Equation 3-59, Page 76 of Wertz, James R., Spacecraft Attitude Determination and Control, Kluwer Academic Publishers, Boston, MA
Timing Precision Mode
This page describes functionality in millisecond timing precision mode. Millisecond timing precision mode is deprecated and will be removed in a future release. We recommend that you migrate your Mission Plans to nanosecond timing precision mode.
Click here to see the documentation for this object in nanosecond timing precision mode.
Attributes
Type: |
number |
Access: |
read/write |
Units: |
m2 |
Default Value: |
1.0 |
Valid Range: |
Spacecraft.SRPArea ≥ 0 |
Syntax
myVariable1 = mySpacecraft1.SRPArea;
mySpacecraft1.SRPArea = myVariable1; |
See also
Coverage and Contact Analysis Guide