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MPB has developed advanced technologies based on smart radiator thin-film tiles (SRTs) employing V1−x−yMxNyOn, for the passive dynamic thermal control of space structures and payloads. The SRT has passed successfully the major ground tests and validated its performance for extended use in the harsh space environment, with a target of up to 15 years GEO, in preparation for a flight demonstration of this technology This paper describes the optimization of MPB's smart radiator and its validation of an efficient thermal control with the tuneability of thermo-optical properties. The thermal control of satellites is a critical subsystem that impacts on the performance and longevity of space payloads. MPB has developed advanced smart radiator devices (SRDs) for passive, dynamic thermal control of space structures and payload. The SRDs employ a nano-engineered, thin-film structure based on V1−x−yMxNyOn. Dopants, M and N, tailor the transition temperature of the IR emittance.

MPB has developed advanced technologies based on smart radiator devices with thin-film tiles (SRDs) employing V1-x-yMxNyOn, for the passive dynamic thermal control of space structures and payloads. M and N dopants tailor the transition temperature characteristics of the tuneable IR emittance. The SRD has successfully passed major ground tests and validated its performance for extended use in the harsh space environment, with a target of up to 15 years GEO, in preparation for a flight demonstration of the technology [1]. This paper describes the optimization and validation of the SRD as an efficient thermal control system with tuneable thermo-optical properties for a microsat mission. The optimization involves tailoring the transition temperature characteristics of the tuneable IR emittance to near room temperature by using Tungsten-doped Vanadium targets for the deposition of V1-xWxOn.

Infrared (IR) spectroscopy probes the characteristic vibrational and rotational modes of chemical bonds in molecules to provide direct information about both the chemical composition and the bonding configuration of a sample. The significant advantage of the IR spectral technique is that it can be used with minimal consumables to simultaneously detect a large variety of different chemical and biochemical species with high chemical specificity. Currently, various VIS/NIR grating spectrometers are employed to cover the spectral range between 0.3 and about 2.2 (μm. Bulk-optic Fourier Transform (FT)-IR spectrometers employing variations of the Michelson interferometer are generally used to provide spectral measurements above 2.5 (μm. The FT-IR systems tend to be mechanically complex, bulky (>15 kg), and require considerable processing, maintenance and recalibration. For space-based systems, the important drivers are reliability, power consumption, mass and simplicity of operation.

MPB has developed advanced smart radiator devices (SRDs) for passive, dynamic thermal control of space structures and payloads. The SRDs employ a nano-engineered, integrated thin-film structure based on V1-x-yMxNyOn. Dopants, M and N, tailor the transition temperature characteristics of the tuneable IR emittance. This paper describes the progress in MPB's smart thermal radiator towards its validation as an efficient thermal control device for space environment. A set of environmental tests were performed in order to validate the coating resistance and performance stability in space. The tests included random vibration, thermal shock, and accelerated aging. In addition, the thermo-optic characteristics after exposure to Atomic Oxygen (AO) in a simulated LEO environment were similar to the “as deposited” characteristics. Preliminary radiation tests, comparable to 3 years in a GEO environment, indicate very low change in emissivity and solar absorptance relative to the initial values.

This paper describes recent advances in MPB's approach to spacecraft thermal control based on a passive thin-film smart radiator tile (SRT) that employs a variable heat-transfer/emitter structure. This can be applied to Al thermal radiators as a direct replacement for the existing OSR (optical second-reflector) radiator tiles with a net added mass under 100 gm/m2. The SRT employs a smart, integrated thin-film structure based on the nano-engineering of V1-x-yMxNyOn that facilitates thermal control by dynamically modifying the net infrared emittance passively in response to the temperature of the space structure. Dopants, M and N, are employed to tailor the transition temperature characteristics of the tuneable IR emittance. This facilitates thermal emissivities below 0.3 to dark space at lower temperatures that enhance the self-heating of the spacecraft to reduce heater requirements.

This paper describes a new approach to spacecraft thermal control based on a passive thin-film smart radiator device (SRD) that employs a variable heat-transfer/emitter structure. The SRD employs an integrated thin-film structure based on V1-x-yMxNyOn that can be applied to existing Al thermal radiators. The SRD operates passively in response to changes in the temperature of the space structure. The V1-x-yMxNyOn exhibits a metal/insulator transition with temperature, varying from an IR transmissive insulating state at lower temperatures, to a semiconducting state at higher temperatures. Dopants, M and N, are employed to tailor the thermo-optic characteristics and the transition temperature of the passive SRD. The transition temperature can be preset over a wide range from below -30°C to above 68°C using suitable dopants. A proprietary SRD structure has been developed that facilitates emissivities below 0.2 to dark space at lower temperatures to reduce heater requirements.