At the core of the Large Synoptic Survey Telescope (LSST) three-mirror optical design is the primary/tertiary (M1M3) mirror that combines these two large mirrors onto one monolithic substrate. The M1M3 mirror was spin cast and polished at the Steward Observatory Mirror Lab at The University of Arizona (formerly SOML, now the Richard F. Caris Mirror Lab at the University of Arizona (RFCML)). Final acceptance of the mirror occurred during the year 2015 and the mirror is now in storage while the mirror cell assembly is being fabricated. The M1M3 mirror will be tested at RFCML after integration with its mirror cell before being shipped to Chile.
The Richard F. Caris Mirror Lab is in the process of fabricating 8.4 meter mirror segments for the Giant Magellan Telescope. Seven of the segments are off-axis with 14 mm of aspheric departure. In order to successfully fabricate these mirrors we are constantly taking steps towards faster, more deterministic methods, from diamond generating to stressed lap polishing. The Large Optical Generator (LOG) is celebrating its 30-year anniversary at the University of Arizona with a complement of technological updates and enhancements. This paper shows how some of these upgrades will aid in the manufacture of the GMT segments.
The Large Optical Test and Integration Site (LOTIS) at the Lockheed Martin Space Systems Company in Sunnyvale,
CA is designed for the verification and testing of optical systems. The facility consists of a large, temperature
stabilized vacuum chamber that also functions as a class 10k cleanroom. Within this chamber and atop an advanced
vibration-isolation bench are the 6.5 meter diameter LOTIS Collimator and Scene Generator, LOTIS alignment and
support equipment. The optical payloads are also placed on the vibration bench in the chamber for testing. The Scene
Generator is attached to the Collimator forming the Scene Projection System (SPS) and this system is designed to
operate in both air and vacuum, providing test imagery in an adaptable suite of visible/near infrared (VNIR) and
midwave infrared (MWIR) point sources, and combined bandwidth visible-through-MWIR point sources, for testing
of large aperture optical payloads. The heart of the SPS is the LOTIS Collimator, a 6.5m f/15 telescope, which projects
scenes with wavefront errors <85 nm rms out to a ±0.75 mrad field of view (FOV). Using field lenses, performance
can be extended to a maximum field of view of ±3.2 mrad. The LOTIS Collimator incorporates an extensive integrated
wavefront sensing and control system to verify the performance of the system, and to optimize its actively controlled
primary mirror surface and overall alignment. Using these optical test assets allows both integrated component and
system level optical testing of electro-optical (EO) devices by providing realistic scene content. LOTIS is scheduled to
achieve initial operational capability in 2008.