1Second Safety Council Meeting• Tucson, AZ• April 10-11, 2014Name of Meeting • Location • Date - Change in Slide Master

The Dome ProjectBill GresslerTelescope & Site Manager

April 10, 2014

Second Safety Council MeetingApril 10-11, 2014 | LSST Project Office N550

2Second Safety Council Meeting• Tucson, AZ• April 10-11, 2014Second Safety Council Meeting• Tucson, AZ• April 10-11, 2014 2

The Telescope and Site Team has developed an Observatory System to perform the LSST Mission

1,380m2 Service and Maintenance Facility

Summit Facility Controls Survey Captures Light Calibrates Conditions

Control Room

Camera Clean Room

Coating Chamber

1.2-m Atmospheric Telescope

30-m Dome

350-ton Telescope

Base Facility Operations Support Data Access Center

WBS Name04C Telescope and Site Construction 04C.00 T&S Level 2 Milestones 04C.01 Telescope System Management 04C.02 Telescope System Engineering 04C.03 Summit Facilities and Infrastructure 04C.04 Dome 04C.05 Telescope Mount 04C.06 Mirror Systems 04C.07 Wavefront and Alignment Systems 04C.08 Calibration System 04C.09 Reflective Coating System 04C.10 Observatory Control System 04C.11 Telescope Control System 04C.12 Utilities and Support Equipment 04C.13 Base Facility and Infrastructure 04C.14 Telescope Integration and Test

3Second Safety Council Meeting• Tucson, AZ• April 10-11, 2014Second Safety Council Meeting• Tucson, AZ• April 10-11, 2014 3

The Dome System

04C.04 Dome - Scope of Subsystem

The Dome is the upper rotating portion of the Telescope Building. It provides the environmental protection of the telescope from the elements during the day.

It has an observing aperture that operates to allow the telescope to view the night sky, rotating and maneuvering to keep the aperture in line with the telescope pointing, while shielding the telescope from stray light and excessive wind.

The Dome includes the structural and sealing elements, the vents for natural flow of air through the telescope enclosure at night and the drive and control systems to provide the necessary motions.

4Second Safety Council Meeting• Tucson, AZ• April 10-11, 2014Second Safety Council Meeting• Tucson, AZ• April 10-11, 2014 4

Numerous design shapes analyzed during the development cycle

− Roll-off/retracting design rejected due to stray light− Rectangular too inefficient; Calotte deemed too risky− Final comparison of carousel vs. spherical− Carousel design chosen after analysis

– Simplified fabrication/erection & cost effective– Better dome ventilation

5Second Safety Council Meeting• Tucson, AZ• April 10-11, 2014Second Safety Council Meeting• Tucson, AZ• April 10-11, 2014 5

Baseline design sized to safely support all handling operations via 20-ton crane

Overhead crane is required to remove & install M1M3 mirror cover for transport to & from coating chamber.

M1M3 Mirror Cell on Cart with cover above

6Second Safety Council Meeting• Tucson, AZ• April 10-11, 2014Second Safety Council Meeting• Tucson, AZ• April 10-11, 2014 6

Design improvements included after discussions with potential vendors

− Camera removal similar to VISTA instrument procedure− Remove through back doors to maintain aperture integrity

7Second Safety Council Meeting• Tucson, AZ• April 10-11, 2014Second Safety Council Meeting• Tucson, AZ• April 10-11, 2014 7

Dome system to be procured via fixed price design/build contract

− Design review May 20-21− RFP in July− Award in late 2014− Design review cycles in SOW− Performance specification− Merge contract into PMCS shedule