G10 collar epoxied into Big Ben. Note that the outer part of the G10 collar has had another later of epoxy applied to cover the ends of the fiberglass revealed when the collar was machined to proper dimensions.
Cryostat stainless steel shell flange after turning on lathe.
Forward thermal shield and LN2 ring, in preparation for welding them into the cold bulkhead shown. The forward thermal shield encloses the collimator and extends to support the slit/decker plate at the telescope focal plane.