Stabilization of Phased Focus Array Using Electrochromic Technology

Significant modulation of solar reflectance, solar absorption, and IR emissivity can be achieved with electrochromic devices operating at very low voltages. They use very little energy and can maintain their state of reflectance, absorption, and emissivityfor some time after the potential has been removed. Devices fabricated as a monolithic stack of solid state inorganic materials can withstand the harsh space environment. These kinds of Variable Electrochromic Devices (VEDs), with no moving parts, are wellsuited for active thermal control of spacecraft and deployable aerospace membrane structures.The Phase I effort will produce 100cm2 VEDs on thin polyimid films with an areal density of 7g/m2 and modulations of emittance from 0.1 to 0.5 and solar absorptance from 0.2 to 0.8. The optical, thermal, and electrical performance of these devices will becharacterized. A detailed calculation will be performed to predict thermal performance of these electrochromic coatings.In Phase II of this effort, samples of the electrochromic devices will be tested to determine their tolerance to high vacuum, UV light, and bombardment with energetic oxygen ions. The design will be optimized to improve performance, reliability, anddurability in the space environment.AEROSPACE¿ Standardized VEM thermal management devices will be developed for use in a variety of spacecraft. They will be deposited on flexible polyimide substrates suited for application to both flat and curved surfaces.¿ Very large area ultra-thin VEM devices will be developed for solar sail applications.¿ Special variable solar thrust panels will be developed to dampen vibrations within large gossamer space structures.VEM thermal management systems will be developed for dimensional stabilization of gossamer and rigid aerospace structures.ARCHITECTURAL GLAZING¿ VEMs will be integrated into insulated glass units to improve the energy efficiency in architectural applications.¿ Vems will be embedded in translucent fiberglass panes to improve the energy efficiency in industrial and commercial applications.8.3 AUTOMOTIVE GLAZING¿ VEMs will be applied to the inside of automotive windows and sun roofs to improve the security and energy efficiency of the vehicles.