NASA - Marshall Space Flight Center

NASA MSFC contracted HEXTEK to fabricate an ultra lightweight borosilicate Gas-Fusion demonstration substrate to be tested cryogencially to 35°K for future space flight capability. NASA MSFC is interested in borosilicate glass because it has almost a near zero cte at 35°K, outperforming Zerodur®, fused silica and ULE®. While NASA will finish the blank to an areal density of 15kg/m², this blank has the potential to be polished to below 8 kg/m².