Back to Chapter 3
Last Updated on July 13, 1998
The telescope is a Ritchey-Chretien configuration with a primary and secondary mirror and baffles. Both the tube-like central baffle and the outer housing have a series of annular baffles for stray light control. The telescope structure is constructed using a graphite-epoxy laminate, which has a very low coefficient of thermal expansion and thus eliminates problems due to thermal expansion. However, the graphite-epoxy laminate is hygroscopic and can change dimensions due to moisture absorption. Care was exercised during integration and test to minimize moisture absorption and to maintain knowledge of the telescope's condition. The central baffle is made from aluminum. The telescope's characteristics are summarized in Table 3.2.
| Table 3.2 | |
|---|---|
| Primary mirror clear aperture outer diameter | 16.0 in (40.64 cm) |
| Primary mirror clear aperture inner diameter | 6.56 in (16.66 cm) |
| Telescope effective clear aperture | 1020 square cm |
| Effective focal length | 96 in (243.8 cm) |
| f/# | 6.0 |
| Mirror material | Ultra-low expansion (ULE) glass |
| Mirror coating | enhanced silver |