Large Optical Test and Integration Site
Encyclopedia
The Large Optical Test and Integration Site, or LOTIS, is a facility at the Lockheed Martin Space Systems
Company in Sunnyvale, CA for testing large optical components under realistic conditions. LOTIS has large, thermally stabilized vacuum chamber
, vibration-isolated optical benches, and a large telescope (run backwards as a collimator) to create images for the test optics to view. It can generate images from the visible through the mid-wavelength IR.
The fabrication error in the Hubble Space Telescope
main mirror is the classic example that shows the need for such testing. In this case, a test facility such as LOTIS was not easily available, so the completed optics were not tested as a unit, and instead relied on careful testing of the individual components. Unfortunately, due to a mis-assembled null corrector
, one of the tests was wrong, and a mis-figured
mirror was not discovered until the telescope was placed into service. This is exactly the type of problem that LOTIS can detect, since it is designed to test large optical systems as a unit by creating realistic inputs and operating conditions for them.
Lockheed Martin Space Systems
Lockheed Martin Space Systems Company is one of the four major business divisions of Lockheed Martin. It is headquartered in Denver, Colorado with additional sites in Sunnyvale, California; Newtown, Pennsylvania; Huntsville, Alabama; and elsewhere in the US and UK...
Company in Sunnyvale, CA for testing large optical components under realistic conditions. LOTIS has large, thermally stabilized vacuum chamber
Vacuum chamber
A vacuum chamber is a rigid enclosure from which air and other gases are removed by a vacuum pump. The resulting low pressure, commonly referred to as a vacuum, allows researchers to conduct physical experiments or to test mechanical devices which must operate in outer space...
, vibration-isolated optical benches, and a large telescope (run backwards as a collimator) to create images for the test optics to view. It can generate images from the visible through the mid-wavelength IR.
The fabrication error in the Hubble Space Telescope
Hubble Space Telescope
The Hubble Space Telescope is a space telescope that was carried into orbit by a Space Shuttle in 1990 and remains in operation. A 2.4 meter aperture telescope in low Earth orbit, Hubble's four main instruments observe in the near ultraviolet, visible, and near infrared...
main mirror is the classic example that shows the need for such testing. In this case, a test facility such as LOTIS was not easily available, so the completed optics were not tested as a unit, and instead relied on careful testing of the individual components. Unfortunately, due to a mis-assembled null corrector
Null corrector
A null corrector is an optical device used in the testing of large aspheric mirrors. A spherical mirror of any size can be tested relatively easily using standard optical components such as laser, mirrors, beamsplitters, and converging lenses. One method of doing this using a Shack cube is shown...
, one of the tests was wrong, and a mis-figured
Figuring
Figuring is the process of final polishing of an optical surface to remove imperfections or modify the surface curvature to achieve the shape required for a given application.-Types of figuring:...
mirror was not discovered until the telescope was placed into service. This is exactly the type of problem that LOTIS can detect, since it is designed to test large optical systems as a unit by creating realistic inputs and operating conditions for them.