The integration and test program of the James Webb Space Telescope

The James Webb Space Telescope (JWST) project has entered into a comprehensive integration and test (I and T) program that over the coming years will assemble and test the various elements of the observatory and verify the readiness of the integrated system for launch. Highlights of the I and T program include a sequence of cryo-vacuum tests of the Integrated Science Instrument Module (ISHvf), to be carried out at NASA's Goddard Space Flight Center (GSFC) and an end-to- end cryo-vacuum optical and thermal test - of unprecedented scale - of the telescope plus instruments at NASA's Johnson Space Center (JSC). The I and T program, as replanned for a 2018 launch readiness date, contains a number of risk-reduction features intended to maximize the prospects for success of the critical tests, leading to reduced cost and schedule risk for those activities. For the JSC test, these include enhancement of the precursor Pathfinder program, the addition of a second cryo-vacuum thermal test of the observatory's Core region, and enhancement of the subsystem level testing program for the cryo-cooler for the Mid-InfraRed Instrument (MlRl). We report here on the I and T program for JWST, focusing on the I and T path for the instruments and telescope, and on the status of the hardware and plans that support it.