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We update performance simulations and contrast predictions for JWST's coronagraphs based on the latest infor- mation on the as-built telescope and instrument properties, including both static and dynamic contributions to wavefront error. By combining optical modeling of the telescope, instruments and coronagraph optics along with STScI's rigorously-validated exposure time calculation engine, we develop updated contrast models including contributions from effects such as target acquisition residuals, stellar color differences, etc. We present assessments of the impact of wavefront error changes over time between science and PSF reference stars, using modeled wavefront drifts on various timescales based on available observatory structural/thermal/optical modeling and tested performance during the OTIS cryo test, extrapolated to on-orbit conditions. For NIRCam we explore tradeoffs between different occulting masks at a given wavelength. Between now and the start of Cycle 1 science, these and other updated simulations will enable the science community to prepare analysis tools and PSF subtraction software to hit the ground running with JWST coronagraphic observations.

Aligning and commissioning the James Webb Space Telescope's segmented mirrors after launch will last many months and involve the telescope itself, all science instruments, and all parts of the observatory ground system. In an effort to assess and demonstrate readiness of the complete end-to-end system - i.e. the flight optical telescope elements (OTE), the Integrated Science Instruments Module, the on-board operational scripts, and the ground processing infrastructure - we performed two operations tests during the JWST OTIS cryogenic campaign in 2017. They are the Wavefront Sensing and Control Demonstration activities at NASA Johnson Space Center (JSC), where we performed flight-like sensing and control using the flight software to command mirror moves and take measurements, and a "Shadow Mode test" at the Space Telescope Science Institute's Mission Operations Center (MOC), where we demonstrated processing of the JSC data through the entire ground system infrastructure. Overall, these tests demonstrated that the full system that will support OTE commissioning is soundly designed although still not fully mature. This paper focuses on the operations and systems testing aspects and some lessons learned. We also report on a series of Wavefront Rehearsals being held at the MOC that are providing additional opportunities to build team readiness in operating the ground system as a whole using high fidelity observatory simulators

A subset of the Wavefront Sensing and Controls (WFSC) operations for JWST were demonstrated during its recent cryo-vac testing using the flight telescope and instruments, and a functional simulation of the spacecraft and ground system. The demonstration had three goals: to confirm the operation of the flight data collection scripts, to check the WFSC optical components, and to verify the coordinates and influence functions that will be used for flight WFSC. In this paper, we present the results and lessons learned from this demonstration.