SDSS 2.5-m Telescope

The SDSS 2.5-m telescope viewed from the monitor telescope dome. The wind baffle fits closely about the telescope. It is supported by the building and protects the telescope from the wind and stray light.

With the wind baffle removed, the secondary truss and interior light baffles are visible. The interior light baffles consist of the secondary, conical and primary baffles (top to bottom). The primary baffle is constructed of a series of annuli terminated by a short truncated cone. The secondary baffle is similar.

A sheet of Tyvek™ covers the primary mirror. Only half of the primary baffle is visible above the Tyvek. The conical baffle is suspended by 1 mm diameter wires from a light-weight frame that is attached to the secondary truss elements.

The edge of the circular floor panel can be seen below the telescope. Mounted to the building structure, it supports the wind baffle. Independent altitude and azimuth drive systems coordinate wind baffle motions with those of the telescope.

The conical baffle (center) blocks stray light paths that would otherwise have to be intercepted by the primary and secondary baffles. This would require larger primary and secondary baffles and would lead to unacceptable blockage of the telescope aperture. The secondary mirror and baffle and the interior of the wind baffle are visible in the background. The primary baffle tip is in the left foreground.