Thermal Modeling in Space: Simulating Satellite Temperatures
By: Tanmay Shidhore
As part of World Space Week, I wanted to share a brief but insightful simulation I ran using Ansys Thermal Desktop — all from my laptop, and in just a few minutes! It demonstrates how a satellite’s temperature changes due to radiative heat transfer as it orbits Earth.
Why Thermal Modeling in Space Matters
In orbit, satellites experience extreme thermal environments. When exposed to direct sunlight, they heat up rapidly. When they pass into Earth’s shadow, they cool just as quickly. These fluctuations can affect performance, longevity, and even structural integrity.
Understanding this thermal behavior is critical in satellite design — and that’s where simulation tools like Thermal Desktop come into play.
The Simulation: Orbit, Radiation, and Temperature
The simulation tracks a satellite as it moves through orbit, with changing thermal inputs depending on its position relative to the Sun and Earth. The video shows an animated visualization of:
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Surface and internal temperature changes over time
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Orbital position vs. thermal response
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Heat loads and radiative fluxes on satellite surfaces
It’s all powered by a Monte Carlo radiation model, which brings us to the real science behind the scenes.
Monte Carlo Radiation Model: A Photon-Based Approach
In space, radiation is the dominant mode of heat transfer. The Monte Carlo model used in this simulation treats the radiation field as a photon gas. Instead of using traditional grid-based methods, this statistical approach traces individual photon paths and interactions.
In essence, it works like this:
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A large number of photons are "launched" into the system.
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Their paths are traced as they reflect, absorb, or scatter.
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The distance traveled, absorption, and scattering coefficients are tallied to calculate:
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Mean radiation intensity
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Absorbed and scattered intensity in each region
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Radiative fluxes on surfaces
Unlike some methods, Monte Carlo doesn’t need to discretize the spectrum. It can handle complex geometries and radiation interactions — making it especially suited for space thermal models.
What Makes This Cool?
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Fast & Local: The whole simulation ran on my laptop in just a few minutes.
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Visual Insight: The animation provides a clear look into how orbital dynamics affect heat distribution.
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Real Physics: The Monte Carlo model provides a physically meaningful way to understand radiation without heavy approximations.
Final Thoughts
Space is harsh, but with the right tools and models, we can design spacecraft that thrive in those extreme conditions. Thermal Desktop + the Monte Carlo model let us simulate, visualize, and understand how satellites behave thermally as they orbit Earth.
Want to see it in action? Check out the video above.
Happy World Space Week!
