Automating the Solar Panel Tool in STK

  • Jul 16, 2020
  • Blog Post

Power is critical to any satellite system, providing the lifeblood for all systems onboard. Understanding the amount of power that a satellite's solar panels can produce is necessary to both the engineering design and mission operations of the satellite.

When you consider the mission of the satellite, it can be difficult to calculate the effective area of its solar panels that are exposed to the Sun. You could take a simple approach and calculate a best-case scenario, a worst case scenario, and apply a safety factor based on the anticipated mission profile. But for effective design and operations, you need to model and operate your satellite in a physics-based simulation environment that effectively mimics reality. This is where STK and the Solar Panel tool come into play.

With STK, you can define a precise model of your satellite and its mission, including solar panel arrays, mission profile, attitude profiles, orbital mechanics, and environmental factors such as lighting and drag. Once your mission is defined, right-click on your satellite object to open the Solar Panel tool. In the tool, choose your time frame and select compute.

To compute the electrical power captured by the solar panels at a given point in time, the System Tool Kit (STK) Solar Panel tool applies the following Basic Power Equation:

Power = Efficiency X Solar Intensity X Effective Area X Solar Irradiance

  • Efficiency is specified for the solar panel in the vehicle model file and ranges between 0 and 100 (%).
  • Solar Intensity ranges from umbra (0) through penumbra (0  <   i  <   1) to full sunlight (1).
  • Effective Area is the cross-sectional area defined above.

Sure you could just read the neatly typed text above, but isn't the light board way cooler?

But I did mention automation ...

Yes, the best part is that you can automate the Solar Panel tool with STK Integration to run trade studies during the engineering design phase. In operations, automation can help you manage an upcoming pass or schedule that has different attitude profiles and power requirements.

Check out this video, which demonstrates a completed code example of automating the Solar Panel tool and provides an explanation of how this patented tool uses GPU processing to calculate the effective area of your solar panels throughout your mission:


You can download this code example on the STK FAQ page, and you can view the code on the AGI GitHub page.


Jeff Baxter