MRLS 76 cm (30") Laser Ranging System
Optical
|
Primary Mirror |
|
|
Diameter |
72.6 cm (30") paraboloid |
|
Focal length |
228.6 m (90") |
|
F-ratio |
3.0 |
|
Cassegrain System |
|
|
Secondary Mirror |
20.0 cm (7.87") hyperboloid |
|
Focal length |
10.67 m (420") |
|
F-ratio |
14.0 |
|
Field angle |
36 arcmin |
|
Plate scale |
19.33 arcsec/min |
|
Coudé System |
|
|
3 cm afocal lens collimates f/14 beam for 2.74 m 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 (532 nm) light. Beam-splitter directs wavelengths < 555 nm to coudé and wavelengths > 555 nm to Cassegrain. |
|
Mechanical
|
Primary Mirror |
|
|
Weight |
116 kg (256 lbs) |
|
Thickness |
12.7 cm (5") |
|
Material |
ULE fused silica |
|
Telescope Tube |
|
|
Diameter |
85.95 cm (33.84") |
|
Length |
153.90 cm (60.59") |
|
Telescope |
|
|
Mount |
alt-alt; horseshoe yoke |
|
Drive |
roller bearings; DC torque motors; 21-bit absolute encoders |
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Tracking |
IBM PC compatible computer running LinuxOS; CAMAC interface |
|
Guiding |
Computer-controlled absolute pointing; Vidicon system at Cassegrain focus |
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Housing |
40 foot semi-transportable carrier, expandable sides; swing-off roof |
Historical
|
Construction |
|
|
Started |
1979 |
|
Funding |
NASA Contract |
|
Contractor |
|
|
Telescope |
Victoria Machine Works |
|
Milestones |
|
|
Aug 1981 |
first LAGEOS acquisition |
|
Aug 1983 |
first lunar acquisition |
