Satellite Spin About the Sun Vector
- Aug 15, 2016
- Systems Tool Kit (STK)
STK has many built-in features that allow you to easily set specific parameters and features depending on your simulation and analysis needs. One commonly used property for satellites is defining their attitude profile as they fly around a central body. STK provides basic and advanced predefined profiles, not only for satellites, but for other objects like aircraft and missiles. The ‘Spin about Sun vector’ profile can be very helpful when evaluating satellite missions, but STK’s predefined profile automatically aligns the satellite’s body z-axis with the Sun vector.
What if I want to spin about the Sun vector, but I have a preset satellite attitude? You can do this with a few extra steps using the ‘Spinning’ predefined attitude profile. The ‘Spinning’ profile properties page contains extra fields for a more customizable attitude definition.
The ‘Body’ axes define the initial rotation of the satellite and the ‘Inertial’ axes are referenced off the central body's inertial axes and define the vector that the satellite will rotate about. You can set these values using Cartesian or spherical coordinates, Euler angles, or pitch/roll angles. For the exact steps to walk through this process and set your satellite’s attitude to spin about the Sun vector, please refer to this Knowledge article.