The Eclipse infrared electro-chromic device (IR-ECD) is an all-solid-state monolithic vacuum deposited
thin film system functioning as an electrically controlled dimmable mirror in the IR region. The maximum
reflectance corresponding to the bleached condition of the system is around 90% (low-e condition, e=0.1).
The minimum reflectance reaches nearly zero in the colored condition of the system (high emmittance,
e=1). It is a variable emittance electro-chromic device (VE-ECD). The average emissivity modulation of
the Eclipse VE-ECD is 0.7 in the 8-12 micron region, and at 9.7 micron (room temperature) it reaches a
value of 0.9. Half and full emissivity modulations occur within 2 and 10 minutes, respectively. Because of
its low mass (5 g/m2), low voltage requirement (±1 V), extremely good emissivity control properties (from
0 to 0.9 at 300 K), and highly repeatable deposition process, the VE-ECD technology is very attractive for
satellite thermal control applications. The Eclipse VE-ECD has been under evaluation in a real space
environment since March 8, 2007. This paper presents recent developments on Eclipse's VE-ECD
including space test results.