Fig. 1. The location of the HEWA on FMG
Fig. 2. Composition of the HEWA
Fig. 3. Coatings of the window glasses
Fig. 4. Transmittance curve of M1
Fig. 5. Transmittance curve of M2
Fig. 6. Thermal design of the HEWA
Fig. 7. Solar radiation transmission from the HEWA to the AOS
Fig. 8. Schematic of the operational modes of FMG
Fig. 9. Schematic of thermal balance test with KFTA
Fig. 10. The HEWA of FMG in KFTA
Fig. 11. Spectral irradiance of the sun and the solar simulator
Fig. 12. Temperature curve of M1 and M2 in three cases
Fig. 13. 3M tape on the +X surface of M1
Fig. 14. Temperature distribution of M1 without/with 3M tape pasted
| Coating | Solar transmittance | Solar absorptivity | Solar reflectance |
|---|
| UV shield | 0.023 | 0.55 | 0.427 | | Narrow-band filter | 0.023 | 0.55 | 0.427 | | IR blocker | 0.028 5 | 0.287 | 0.684 5 |
|
Table 1. The equivalent solar radiation parameters of each coating
| Item | Case 1 | Case 2 | Case 3 |
|---|
| Cold case | Hot case | Calibration case |
|---|
| Simulation date | Summer solstice | Winter solstice | Winter solstice | | Solar irradiance | 1 300 W/m2 | 1 450 W/m2 | 1 450 W/m2 | | Satellite attitude | Sun oriented | Sun oriented | Deviating maneuver | | Simulation orbit periods | 20 | 20 | 20 | | Initial temperature | 18℃ | 18℃ | 18℃ | | Surface radiation characteristics | BOL | EOL | EOL | | Outer surface of the mounting board | -50℃ | -10℃ | -10℃ | | Outer surface of the satellite heat-shield | -90℃ | -60℃ | -60℃ | | Radiation interface of other payloads | -60℃ | -10℃ | -10℃ | | Optic box | 20℃ | 24℃ | 24℃ |
|
Table 2. Parameters of each analysis case
| Materials | αs | εh | ρ/ （kg·m-3） | C/ （J·kg-1·K-1） | λ/ （W·m-1·K-1） |
|---|
| F46 | 0.13（BOL） 0.30（EOL） | 0.73 | / | / | / | | S781 | 0.20（BOL） 0.40（EOL） | 0.86 | / | / | / | | LY12 | 0.88 | 0.88 | 2 710 | 946 | 117.2 | | TC4 | 0.88 | 0.88 | 4 450 | 678 | 5.44 | | Fused SILICA | / | / | 2 205 | 766 | 1.31 | | Glass fiber reinforced plastic | / | / | 1 400 | 1 110 | 0.342 |
|
Table 3. Thermo-physical parameters of materials and radiation characteristics of coatings
| Case | Baffle | UV shield | Narrow-band filter | IR blocker 1 | IR blocker 2 | Primary mirror |
|---|
Theoretical calculation（only primary reflection and transmission are considered） | / | 0.607 W | 0.334 W | 0.218 W | 0.066 W | 0.041 5 W | | Case 1（100% mirror reflection） | 4.64 W | 0.812 W | 0.572 W | 0.470 W | 0.199 W | 0.101 W | | Case 1（80% mirror reflection） | 6.39 W | 0.763 W | 0.534 W | 0.427 W | 0.159 W | 0.073 5 W | | Case 2（100% mirror reflection） | 8.51 W | 1.01 W | 0.754 W | 0.616 W | 0.258 W | 0.134 W | | Solar | 4.81 W | 0.95 W | 0.75 W | 0.616 W | 0.258 W | 0.134 W | | Albedo | 0.53 W | 0.000 4 W | 0.000 26 W | 0.000 18 W | 0.000 067 5 W | 0.000 023 9W | | Planet | 3.16 W | 0.0527 W | 0 | 0 | 0 | 0 | | Case 2（80% mirror reflection） | 10.89 W | 0.939 W | 0.709 W | 0.562 W | 0.209 W | 0.113 W | | Case 3（100% mirror reflection） | 22.2 W | 0.33 W | 0.165 W | 0.108 W | 0.029 9 W | 0.010 W | | Case 3（80% mirror reflection） | 21.85 W | 0.329 W | 0.164 W | 0.111 W | 0.032 8 W | 0.001 W |
|
Table 4. Absorbed heat flux of different components of HEWA in the three analysis cases
| Components | Index /℃ | Case 1 | Case 2 | Case 3 |
|---|
| 100% mirror reflection /℃ | 80% mirror reflection /℃ | 100% mirror reflection /℃ | 80% mirror reflection /℃ | 100% mirror reflection /℃ | 80% mirror reflection /℃ |
|---|
| Baffle | / | -9.0~-1.2 | -7.2~-0.5 | -4.2~2.0 | -3.0~2.8 | 11.5~26.5 | 11.0~26.0 | | Window frame | 0~50 | 4.5~5.5 | 4.7~5.8 | 4.7~5.8 | 5.1~6.0 | 14.7~27.0 | 14.0~26.0 | | M1 | 0~50 | 4.5~7.2 | 4.6~7.2 | 6.4~8.2 | 6.0~7.8 | 15.0~24.0 | 14.6~23.4 | | M2 | 0~50 | 7.0~9.3 | 7.0~9.4 | 8.0~9.9 | 7.6~9.7 | 17.0~24.4 | 17.6~24.0 | | Primary mirror | 22±2 | 21.1~22.2 | 21.1~22.1 | 21.3~22.2 | 21.4~22.2 | 21.8~22.4 | 21.6~22.2 |
|
Table 5. Thermal analysis results of the HEWA
| Components | Index /℃ | Case 1 | Case 2 | Case 3 |
|---|
| Test results/℃ | Analysis results /℃ | Test results/℃ | Analysis results /℃ | Test results/℃ | Analysis results /℃ |
|---|
| Baffle | / | -20.3~-19.0 | -9.0~-1.2 | -12.7~-10.5 | -4.2~2.0 | 7.2~23.3 | 11.5~26.5 | | Window frame | 0~50 | 0.1~5.1 | 4.5~5.5 | 0.9~5.3 | 4.7~5.8 | 14.7~26.5 | 14.7~27.0 | | M1 | 0~50 | 7.2~8.4 | 4.5~7.2 | 10.4~11.7 | 6.4~8.2 | 14.9~32.8 | 15.0~24.0 | | M2 | 0~50 | 8.3~10.5 | 7.0~9.3 | 9.2~11.1 | 8.0~9.9 | 18.7~22.8 | 17.0~24.4 | | Primary mirror | 22±2 | 21.7~21.8 | 21.1~22.2 | 21.7~21.9 | 21.3~22.2 | 21.8~22.3 | 21.8~22.4 |
|
Table 6. Thermal balance test results of the HEWA
| Components | Index /℃ | Case 1 | Case 2 | Case 3 |
|---|
Modified analysis results/℃ | Test results/℃ | Modified analysis results/℃ | Test results/℃ | Modified analysis results/℃ | Test results/℃ |
|---|
| Baffle | / | -22.0~-15.0 | -20.3~-19.0 | -15.5~-8.2 | -12.7~-10.5 | 5.4~24.1 | 7.2~23.3 | | Window frame | 0~50 | -0.2~5.2 | 0.1~5.1 | 0.6~5.2 | 0.9~5.3 | 11.5~26.8 | 14.7~26.5 | | M1 | 0~50 | 7.0~8.6 | 7.2~8.4 | 8.5~11.3 | 10.4~11.7 | 14.8~32.6 | 14.9~32.8 | | M2 | 0~50 | 8.5~10.5 | 8.3~10.5 | 10.0~11.5 | 9.2~11.1 | 18.0~23.3 | 18.7~22.8 | | Primary mirror | 22±2 | 21.7~22.3 | 21.7~21.8 | 22.0~23.0 | 21.7~21.9 | 21.8~23.5 | 21.8~22.3 |
|
Table 7. Comparison of the modified analysis results and the test results
| Components | Index/℃ | Case 1/℃ | Case 2/℃ | Case 3/℃ |
|---|
| Baffle | / | -18.0~-10.0 | -8.5~-1.0 | 7.1~26.2 | | Window frame | 0~50 | 4.4~5.3 | 4.5~5.5 | 12.7~28.2 | | M1 | 0~50 | 6.2~7.4 | 7.5~8.8 | 16.5~26.3 | | M2 | 0~50 | 8.5~10.5 | 10.0~11.5 | 18.5~23.5 | | Primary mirror | 22±2 | 21.7~22.3 | 22.0~23.0 | 21.5~23.0 |
|
Table 8. Prediction of the temperature distribution of the HEWA on orbit
