Spacecraft.Bstar Property

Top 

Description

This property has been Deprecated. Please use Spacecraft.SGP4.Bstar instead.

 

A special "drag" term associated with the Norad SGP4/SDP4 propagators. It measured in units of 1/earth radii and is related to the Spacecraft's Cd. It is obtained by having FreeFlyer import the NORAD Two-Line Element (TLE) state vector. It is also computed by FreeFlyer when a conversion from Cartesian elements to Norad element is invoked.

 

B* is calculated as follows:

 

 

Where:

ρ0 Norad Atmospheric Density, 2.461e-5 kg/m2/RE

CD Coefficient of drag

A Spacecraft drag area in m2

RE Norad Earth Radius, 6378.135 km

m Spacecraft mass in kg

 

 

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

Units:

er-1

Default Value:

0.0002

 

Syntax

myVariable1 = mySpacecraft1.Bstar;

 

mySpacecraft1.Bstar = myVariable1;

 

See also

Spacecraft Object

Spacecraft Propagation Guide

Coverage and Contact Analysis Guide