Smart and Flexible Optical Solar Reflectors for Passive Radiative Cooling Regulation in Space Using a W:VO₂...

Area of Science:

• Materials Science
• Aerospace Engineering
• Nanotechnology

Background:

• Passive thermal management is crucial for spacecraft.
• Smart optical solar reflectors (OSRs) with adaptive emission are needed for efficient thermal control.
• Existing OSRs face challenges in performance and integration.

Purpose of the Study:

• To develop a flexible, smart metasurface-based OSR (meta-OSR) for passive spacecraft thermal management.
• To demonstrate a meta-OSR with temperature-adaptive radiative emission around room temperature.
• To assess the performance and space-readiness of the fabricated meta-OSR.

Main Methods:

• Fabrication of a W:VO2-based metasurface integrated with a low emissivity solar reflector.
• Utilizing nanoimprint lithography and a low-temperature W:VO2 process.
• Testing the meta-OSR's optical properties, transition temperature, and performance under space qualification conditions.

Main Results:

• The smart meta-OSR exhibits a solar absorption of 0.22 and high-temperature emissivity of 0.8.
• Achieved an infrared emissivity contrast of 0.33 and a transition temperature (T_MIT) of 30°C.
• Demonstrated large-area (10x10 cm2) fabrication on polyimide, passing rigorous space qualification tests with negligible degradation.

Conclusions:

• The developed smart meta-OSR offers significant weight reduction and easy integration for spacecraft.
• The device is production-ready and demonstrates robust performance under space environmental conditions.
• This technology represents a next-generation thermal control solution for ultralight spacecraft and small satellites.