Optical coating considerations for cryogenic mirrors used in AEDC's 7V and 10V space sensor test chambers*

Abstract

The ground testing of a sensor system under flight conditions is fundamental to characterizing its performance. It should be accomplished early and often in order to manage operational uncertainty and reduce system life-cycle cost. As a DoD Major Range Test Facility Base (MRTFB), the Arnold Engineering Development Center (AEDC) provides a comprehensive capability that strives to ensure system performance evaluations that are not limited by test infrastructure. For over 30 years, the space chambers at AEDC have performed space-sensor characterization, calibration, and mission simulation testing on space-based, interceptor, and airborne sensors. In partnership with Missile Defense Agency (MDA), capability upgrades are continuously pursued to keep pace with evolving sensor technologies. A critical aspect of these chambers is the quality of the mirror coatings used to project simulated target scenes to the unit under test in low-background cryogenic conditions. This paper discusses the recent effort at AEDC to refurbish and/or replace the mirror collimating systems in their 7V and 10V Aerospace Chambers and the coating choices that have been considered.