Development of an Innovative System for Cryodeposit Mitigation and Redmediation

ABSTRACT: Physical Sciences Inc. (PSI) and the University of Tennessee Space Institute (UTSI) propose to develop an innovative system to measure and control the cryodeposit layer thickness that develops on cold surfaces in cryogenic radiometric calibration chambers. The system includes: 1) an in-situ, interferometric-based instrument to monitor the cryodeposit layer thickness, 2) a mitigation system to inhibit the growth of cryodeposits on key system components, and 3) a remediation system based upon a photodesorption process to remove the cryolayer before it substantially impacts the optical performance of key components of the calibration chamber. The goal of the Phase I program is to characterize the performance of both mitigation and remediation approaches. UTSI will measure the growth rate of water-ice films in a cryogenic vacuum chamber to characterize the effectiveness of a controlled electric field-based mitigation technology. PSI will measure the water-ice desorption rate from cryogenic surfaces as a function of ultraviolet and infrared illumination source characteristics. These results will be compared to quantitative performance metrics developed with the Air Force to design the Phase II prototype system. The prototype cryodeposit mitigation/remediation system will be further refined and the system will be tested in the laboratory during the Phase II program. BENEFIT: The proposed cryodeposit mitigation/remediation system will provide the aerospace industry with a new, innovative tool that will substantially increase the productivity of cryogenic radiometric calibration chambers by reducing maintenance activities currently required to ameliorate the effects of cryodeposit layers that form on optical surfaces during cryogenic calibration activities. The proposed cryodeposit mitigation/remediation system will therefore substantially reduce both the duration and cost of cryogenic radiometric calibration chamber test activities.