Enhanced Blackbody Sensors for the Quench Module Insert

Experiment Modules (EM) such as the Quench Module Insert (QMI) must be comprised of robust components to minimize the need for recalibration and refurbishment/replacement on the International Space Station. A critical aspect for proper operation of the QMI is thermal performance monitoring by blackbody sensors (BBS). Significant improvements in the ability of the sensor to monitor thermal performance can be realized by improving the joint quality between BBS rings and tantalum sheathed thermocouples. Modification of the sensor rings' surface properties to increase emissivity benefits thermal performance. In Phase I, novel laser brazing techniques have been developed for the production of robust joints between tantalum sheathed thermocouples and BBS rings. Additionally, an ultra high temperature tantalum carbide emissivity coating has been developed for use with tantalum sensor rings for improved radiative heat transfer properties. Thermal cycle testing demonstrated excellent joint quality of the enhanced BBS and the bond between TaC emissivity coatings and tantalum sensor rings. During Phase II, the techniques will be optimized such that enhanced flight quality BBS will be fabricated for testing in QMI furnaces at Marshall Space Flight Center.