Description
The Coefficient of Reflectivity is a property that is a function of the properties of the spacecraft's area incident to the Sun-Earth line. It is used in the calculation of the force on the spacecraft due to solar radiation pressure.
Note that this value is only used when ForceModel.SRPForceGeometry is set to spherical. If using a plate model, the coefficients of reflectivity should be set for each individual plate.
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 nanosecond timing precision mode.
Click here to see the documentation for this object in millisecond timing precision mode.
Attributes
Type: |
number |
Access: |
read/write |
Default Value: |
1.4 |
Syntax
myVariable1 = mySpacecraft1.Cr;
mySpacecraft1.Cr = myVariable1; |
See also
Coverage and Contact Analysis Guide