  The James Webb Space Telescope (JWST) Optical Simulation Testbed (JOST) is a
hardware simulator for wavefront sensing and control designed to produce
JWST-like images. A model of the JWST three mirror anas- tigmat is realized
with three lenses in the form of a Cooke triplet, which provides JWST-like
optical quality over a field equivalent to a NIRCam module. An Iris AO
hexagonally segmented mirror stands in for the JWST primary. This setup
successfully produces images extremely similar to expected JWST in-flight point
spread functions (PSFs), and NIRCam images from cryotesting, in terms of the
PSF morphology and sampling relative to the diffraction limit. The segmentation
of the primary mirror into subapertures introduces complexity into wavefront
sensing and control (WFS&C) of large space based telescopes like JWST. JOST
provides a platform for independent analysis of WFS&C scenarios for both
commissioning and maintenance activities on such ob- servatories. We present an
update of the current status of the testbed including both single field and
wide-field alignment results. We assess the optical quality of JOST over a wide
field of view to inform the future imple- mentation of different wavefront
sensing algorithms including the currently implemented Linearized Algorithm for
Phase Diversity (LAPD). JOST complements other work at the Makidon Laboratory
at the Space Telescope Science Institute, including the High-contrast imager
for Complex Aperture Telescopes (HiCAT) testbed, that investigates coronagraphy
for segmented aperture telescopes. Beyond JWST we intend to use JOST for WFS&C
studies for future large segmented space telescopes such as LUVOIR.

Instrumentation and Methods for Astrophysics