Project Title:

A Variable Transmittance Electrochromic Space Suit Visor

12.01-9450
A Variable Transmittance Electrochromic Space
	Suit Visor
EIC Laboratories, Inc.
111 Downey Street
Norwood, MA 02062
Stuart F. Cogan  (617-769-9450)
JSC -- NAS9-17939

Abstract:

	 An astronaut in a space suit will experience sharp changes in direct and indirect
solar flux which can result in visual impairment. Present helmet assemblies are equipped
with a fixed transmittance sun-visor and opaque fiberglass eye shades that are manipulated
manually by the astronaut. The proposed innovation is a variable transmittance sun-visor
based on electro-chromic optical switching. The sun-visor would have a laminated,
thin-film structure that could be integrated into the protective visor of a spacesuit
helmet assembly. The visor would have an optical transmittance  variable between
10 and 70 percent controlled by the astronaut or an automatic sensor. Selective modulation
of prescribed locations on the helmet is possible, allowing built-in peripheral eye
shading. 
	The Phase I program demonstrated electro-chromic switching in polycarbonate laminates
and near-neutral density optical modulation. Electro-chromic devices on glass substrates
have been tested for 20,000 full switching cycles without degradation, with typical
switching ranges between 15 and 65 percent transmittance (400-700 nm). Thus far the
program has emphasized an electro-chromic system based on thin films of amorphous
tungsten trioxide and amorphous iridium oxide which color and bleach synchronously
in a laminated structure.

Potential Commercial Application:

Potential Commercial Application: Aerospace applications include sun-visors, space
vehicle windows, optical scientific equipment, and thermal management/glare control
coatings in aircraft transparencies. Terrestrial commercial opportunities include
eye-wear, automobile sunroofs, variable reflectance mirrors, optical equipment, and
some building window applications.