Thermal Modeling in Space: Simulating Satellite Temperatures

Simulate satellite thermal behavior in orbit. Explore how a Monte Carlo model demonstrates temperature changes as it moves through space.
Dec. 2, 2025
3 min read

Key Highlights

  • The simulation tracks a satellite's surface and internal temperature changes as it orbits Earth, considering varying thermal inputs from sunlight and Earth's shadow.
  • Monte Carlo radiation modeling treats space radiation as a photon gas, allowing for detailed and accurate heat transfer analysis in complex geometries.
  • The entire thermal simulation runs on a laptop in just a few minutes, providing quick insights into orbital thermal dynamics.

The attached video shares a brief, but insightful simulation using Ansys Thermal Desktop—all from a 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:

  • Surface and internal temperature changes over time
  • Orbital position vs. thermal response
  • 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.

READ MORE: Simpler, Smaller and Smarter: Simulation Tactics for Better Product Design

In essence, it works like this:

1. A large number of photons are “launched” into the system.

2. Their paths are traced as they reflect, absorb or scatter.

3. The distance traveled, absorption and scattering coefficients are tallied to calculate:

  • Mean radiation intensity
  • Absorbed and scattered intensity in each region
  • 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?

  • Fast and local. The whole simulation ran on my laptop in just a few minutes.
  • Visual insight. The animation provides a clear look into how orbital dynamics affect heat distribution.
  • Real physics. The Monte Carlo model provides a physically meaningful way to understand radiation without heavy approximations.

READ MORE: How Multiphysics Simulation Accelerates Innovation in Energy, Healthcare & Manufacturing

Final Thoughts

Space is harsh but with the right tools and models, we can design spacecraft that thrive in those extreme conditions. Thermal Desktop, combined with the Monte Carlo model, allows us to simulate, visualize and understand how satellites behave thermally as they orbit Earth.

Tanmay Shidhore submitted the simulation on behalf of Rand Simulation.

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