JWST Overview and Successful Operation of the Cryo-Vac Test at NASA JSC During Hurricane Harvey

The JWST Optical Telescope Element (OTE) assembly is the largest optically stable infrared-optimized telescope. The primary mirrors, secondary mirror, and the Aft Optics Sub-systems (AOS) are designed to be passively cooled and operate at near 45K. This paper describes the JWST cryogenic test program, focusing on the series of integrated `Pathfinder' cryogenic vacuum tests and finally performing the cryo-vac test of the Flight Optical Telescope Element mated with the Science Instruments as an integrated assembly (OTIS). The JWST OTIS cryo-vac was carefully planned, designed to safely manage numerous challenging risks, and executed in a highly-orchestrated operation. Although the OTIS test was operated and on-schedule as planned, the mother-nature provided an extreme challenge in the form of Harvey, a Category-4 Hurricane. Presented in this paper is an overview of the in-situ test operations and innovative solutions developed in real time to maintain the flight hardware safety with dwindling supplies of consumable materials, such as Liquid Nitrogen, while continuing with the cryo-vac test in the midst of one of the largest natural disaster.