Organizations: Key Laboratory for Satellite Digitalization Technology, Innovation Academy for Microsatellites, Chinese Academy of Sciences, Shanghai, China · School of Aeronautics and Astronautics, Shanghai Jiao Tong University, Shanghai, China
Spacecraft thermal design requires repeated evaluation of how variations in the number and spatial arrangement of heat-generating components and in thermal boundary conditions affect the temperature field. High-fidelity numerical simulations are computationally expensive and therefore difficult to use for large-scale design screening. Although surrogate models can accelerate temperature-field prediction, existing approaches generally encode each complete configuration as a whole and do not explicitly exploit the reusability of local physical constituents across configurations, which limits their accuracy for component counts and combinations not covered during training. To address this issue, we propose the Tree-Structured Factor Composition Network (TFCN), which decomposes complex spacecraft thermal configurations into reusable local physical factors and employs a tree-structured composition module to learn the global temperature-field response associated with different factor combinations. TFCN is evaluated on two-dimensional steady-state spacecraft thermal-analysis cases with prescribed-temperature and radiative-flux boundary conditions. The model is trained exclusively on configurations containing no more than 15 heat-generating components and evaluated on unseen configurations containing 16-25 components. For the prescribed-temperature and radiative-flux cases, TFCN achieves component-count out-of-distribution RMSE values of 4.21 K and 18.62 K, respectively, representing reductions of 65.6% and 33.6% relative to the strongest baseline. These results demonstrate that TFCN improves the reliability of temperature-field prediction under variations in component count and provides an efficient surrogate for rapid spacecraft thermal-design evaluation and large-scale configuration screening.
Figures & tables
Category
Method
Phys. loss constraint
Variable-count feature input
Object/subblock encoding
Shared recursive composition
Physical consistency constraints
PINN (2019) [ 11 ]
✓
×
×
×
PI-ML (2023) [ 7 ]
✓
×
×
×
PI-DeepONet (2024) [ 12 ]
✓
×
×
×
DSSL (2026) [ 8 ]
✓
×
×
×
Spatial/set representation
DeepSets (2017) [ 13 ]
×
✓
✓
×
GINO (2023) [ 14 ]
×
✓
✓
×
Table 1: Literature-level feature matrix for related physical-field surrogate methods.
Figure 1: From a componentized spacecraft layout to the two-dimensional HSL-TFP problem. The underlying problem follows the general heat-source-layout benchmark of Chen et al. [ 21 ] , and its spacecraft-oriented extension follows our previous work [ 8 ] .
Figure 2: Automated data-generation pipeline inherited from our previous work [ 8 ] .
Figure 3: Data construction and evaluation splits.
Figure 4: Overall TFCN framework.
Figure 5: Multi-path latent-space composition.
Dataset
Method
K -ID
K -OOD
RMSE
MAE
RMSE
MAE
Temp-BC
UNet
9.99±0.27
6.83±0.10
46.91±1.56
33.52±1.22
DeepONet
12.94±0.24
9.18±0.12
38.95±1.19
29.13±0.68
GINO
3.09±0.15
2.06±0.04
12.23±0.55
5.42±0.32
TFCN-SP
4.88±0.76
2.97±0.42
15.66±2.00
9.12±2.37
TFCN-TP
1.45±0.13
0.95±0.07
4.21±0.15
2.56±0.09
Table 2: Interpolation and high-component-count extrapolation performance. Values are reported as mean ± standard deviation over five independent runs.
Figure 6: Per- K extrapolation error.
Figure 7: Training coverage and composition depth.
Dataset
Method
K -ID
K -OOD
OOD/ID
RMSE
MAE
RMSE
MAE
Temp-BC
TFCN-SP
4.88
2.97
15.66
9.12
3.209
w/o Locality
4.35
2.53
18.49
10.29
4.254
w/o Composition
18.62
11.58
54.03
40.11
2.902
RadFlux-BC
TFCN-SP
10.53
7.32
23.06
15.45
2.190
w/o Locality
10.00
7.12
25.29
15.70
2.529
Table 3: Structural ablation results.
Figure 8: PHATE diagnostic of intermediate-representation geometry.
Figure 9: MMD diagnostic of the ID/OOD latent-distribution discrepancy.
Figure 10: Single-sample intermediate-representation diagnostic during factor composition. Intermediate panels are decoder projections; only the fully composed 15/15 panel is the final full-system temperature prediction and uses the Kelvin scale.
Appendix figures & tables12 assets
Supplementary material from the paper’s appendix.
Appendix
Symbol
Meaning
Ωh
Discrete grid
G
Coordinate condition
C
Heat-source components
B
Boundary segments
F
Factors
fi
Factor representation
Appendix
Table 1: Summary of principal notation used in TFCN.