The LSST Summit Facility will be located on the Cerro Pachón ridge in north-central Chilé. The entire Cerro Pachón area, including the proposed LSST site and the existing Gemini-south and SOAR telescopes, is within a tract of land owned by AURA Inc. The telescope sites are inland and approximately 100 km by road from the support town of La Serena, where the LSST Base Facility is proposed to be located.
The proximity of the Gemini and SOAR telescopes allows for significant
savings in the sharing of infrastructure services and utilities.
The LSST Summit Support Facility includes:
the telescope pier; a 30m-diameter lower enclosure that will support a rotating dome (contracted separately); a service and operations building of approximately 3000 m2 attached to the lower enclosure; and a separate enclosure for a calibration telescope. Design requirements have been established for all these building structures. Preliminary plans have been developed to establish their basic layout and to allow initial in-house and contracted cost estimates. LSST Summit Facility design takes advantage of the natural topography of the El Peñón ridge. The main telescope enclosure occupies the highest and largest peak with the attached service and operations building stepping down into a saddle area to the southeast. The calibration telescope is
on a smaller peak farther to the east.
Extensive site weather testing and computational
fluid dynamic analysis have been conducted to
verify that this general site arrangement will maintain a beneficial seeing environment for the telescope. Further CFD analysis and layout studies will be performed to help refine the final site and building design.
Preliminary geotechnical study has been conducted to assess the quality of the natural rock on site and to allow initial foundation design. The rock strata at the anticipated level of the telescope foundation is shown to be of very high competency with stiffness values well above that of concrete.
Design and specification of initial site leveling work has been completed and construction documents are ready for contracting. The primary excavation method is expected to be a horizontal drilling and blasting technique that preserves the structural competency of the remaining rock strata below. The result of that initial excavation will be level platforms for construction of the the two telescopes and suitable access roads.
A longitudinal section through the telescope enclosure and the service & operations building illustrates the stepped-down arrangement of the interior facilities of the service and operations building. This provides a contiguous protected environment for transporting and maintaining the camera and mirrors while still creating beneficial separation between the telescope and the conditioned spaces of the observatory facility. The heated operations spaces are below the service level with the heat generating equipment located below that and farthest from the telescope. An 80-ton platform lift will convey mirrors and camera to and from the telescope.
Equipment that will be accommodated in the Support Facility includes a camera servicing facility equipped with clean room spaces for working inside the cryostat that protects and cools the CCD detectors. The on-site service building also includes a dedicated cleaning and coating facility to be used for both the 8.4m primary/tertiary mirror and the 4m secondary mirror. The mirrors and camera are not expected to leave the mountain, receiving all necessary service at the summit facility during their entire operational life.
A scope of work and schedule for the LSST Summit Support Facility architectural services has been developed. The early design phase beginning in 2010 will include further development of the preliminary design and preparation of work package for initial site utility installation. The target for completion of construction documents for the entire LSST Summit Facility design is the beginning of fiscal year 2012.