|
Programs
|
Lunar Laser Ranging Program
|
Optical
|
Primary Mirror
|
diameter:
|
72.6cm (30") paraboloid
|
focal length:
|
228.6m (90")
|
f-ratio:
|
3.0
|
Cassegrain System
|
2ndary mirror:
|
20.0cm (7.87") hyperboloid
|
focal length:
|
10.67m (420")
|
f-ratio:
|
14.0
|
field angle:
|
36 arcmin
|
plate scale:
|
19.33 arcsec/mm
|
Coudé System
3 cm afocal lens collimates f/14 beam for 2.74m travel path to beam-expanding and beam-splitting
optics before entering laser and photo multiplier housings.
|
Coatings
Coudé path optics coated to maximize transmission of green (532nm) light. Beam-splitter directs wavelengths
< 555nm to coudé and wavelengths > 555nm to Cassegrain.
|
Mechanical
|
Primary Mirror
|
weight:
|
116kg (256 lbs)
|
thickness:
|
12.7cm (5")
|
material:
|
ULE fused silica
|
Telescope Tube
|
diameter:
|
85.95cm (33.84")
|
length:
|
153.90cm (60.59")
|
Telescope
|
mount:
|
alt-alt; horseshoe yoke
|
drive:
|
roller bearings; DC torque motors; 21-bit absolute encoders
|
tracking:
|
IBM PC compatible computer running LinuxOS; CAMAC interface
|
guiding:
|
Computer-controlled absolute pointing; Vidicon system at Cassegrain focus
|
housing:
|
40-foot semi-transportable carrier, expandable sides; swing-off roof
|
Historical
|
Construction
|
started:
|
1979
|
funding:
|
NASA Contract
NASW-3296
|
Contractor
|
telescope:
|
Victoria Machine Works
|
Milestones
|
Aug 1981:
|
first LAGEOS acquisition
|
Aug 1983:
|
first lunar acquisition
|
|
|
