Architecting a revised optical test approach for JWST

Abstract

It is imperative that we have high confidence that the optical performance capability of JWST is well-understood before launch. With the telescope operating at cryogenic temperatures and sporting a 6.6 meter primary mirror diameter, the optical metrology equipment required to measure the optical performance can be quite complex. The JWST Test team undertook an effort to greatly simplify the optical metrology approach, while retaining the key measurements and verification methodology. The result is a cryogenic optical test configuration and implementation using Chamber A at NASA's Johnson Space Center that uses the science instruments to help understand JWST's optical performance.