In 2014, the Optical Ground Support Equipment was integrated into the large cryo vacuum chamber at Johnson Space Center (JSC) and an initial Chamber Commissioning Test was completed. This insured that the support equipment was ready for the three Pathfinder telescope cryo tests. The Pathfinder telescope which consists of two primary mirror segment assemblies and the secondary mirror was delivered to JSC in February 2015 in support of this critical risk reduction test program prior to the flight hardware. This paper will detail the Chamber Commissioning and first optical test of the JWST Pathfinder telescope.
The gas cloud imager (GCI) is a passive uncooled multispectral camera capable of unprecedented sensitivity for
analyzing hydrocarbon gas mixtures in a scene. The GCI is currently finishing its final stages of development,
and promises to obtain a 220×220 image of gas concentrations at 30 frames/sec, allowing for real-time display in
a compact instrument without moving parts. We summarize measurement approach and discuss the advantages
of the GCI instrument design against conventional instruments.